Conformational change in the pheromone-binding protein from Bombyx mori induced by pH and by interaction with membranes.
AuthorsWojtasek H,Leal WS
JournalThe Journal of biological chemistry
PubMed ID10521490
Cofactor-induced refolding: refolding of molten globule carbonic anhydrase induced by Zn(II) and Co(II).
AuthorsAndersson D,Hammarström P,Carlsson U
JournalBiochemistry
PubMed ID11258876
Rapid irreversible G protein alpha subunit misfolding due to intramolecular kinetic bottleneck that precedes Mg2+ "lock" after GTP/GDP exchange.
AuthorsZelent B,Veklich Y,Murray J,Parkes JH,Gibson S,Liebman PA
JournalBiochemistry
PubMed ID11583165
Stoichiometric exchange of GTP for GDP on heterotrimeric G protein alpha (Galpha) subunits is essential to most hormone and neurotransmitter initiated signal transduction. Galphas are stably activated in a Mg2+ complex with GTPgammaS, a nonhydrolyzable GTP analogue that is reported to bind Galpha, with very high affinity. Yet, it is ... More
Differential perturbation of intersubunit and interdomain communications by glycine 141 mutation in Escherichia coli CRP.
AuthorsCheng X, Lee JC
JournalBiochemistry
PubMed ID9425025
Upon binding of cAMP, concomitant changes in CRP structure across the subunit and domain interfaces are observed. In order to identify the structural elements involved in the coupling of interfacial interactions, structural perturbation was introduced at residue 141 by site-directed mutagenesis. Thermodynamic parameters defining protein stability, cAMP binding, and subunit ... More
Phosphorescence from 2-(p-toluidinyl)naphthalene-6-sulfonate and 1-anilinonaphthalene-8-sulfonate, commonly used fluorescence probes of biological structures.
AuthorsManiara G, Vanderkooi JM, Bloomgarden DC, Koloczek H
JournalPhotochem Photobiol
PubMed ID3344289
Calcium-induced phase separation in phospholipid bilayers. A fluorescence anisotropy study.
AuthorsParasassi T, de Felip E, Lepore F, Conti F
JournalCell Mol Biol
PubMed ID3742537
Enzyme-based visualization of receptor-ligand binding in tissues.
'New methods of elucidating the ligand-binding activity of receptors could improve our understanding of receptor function, key events they control, and their presence in normal and pathological states. We describe a method for visualizing receptor-ligand binding in cells and tissues that substitutes fluorescein for radioactive labels, and detects receptor bound, ... More
Detection of one attomole of [Arg8]-vasopressin by novel noncompetitive enzyme immunoassay (hetero-two-site complex transfer enzyme immunoassay).
AuthorsHashida S, Tanaka K, Yamamoto N, Uno T, Yamaguchi K, Ishikawa E
JournalJ Biochem (Tokyo)
PubMed ID1778973
'One attomole of [Arg8]-vasopressin (AVP) was detected by a novel noncompetitive enzyme immunoassay (hetero-two-site complex transfer enzyme immunoassay). AVP was indirectly biotinylated using N-hydroxysuccinimidobiotin and trapped onto an anti-AVP IgG-coated polystyrene ball. After washing, biotinylated AVP was eluted from the polystyrene ball with HCl and was reacted with 2,4-dinitrophenyl-fluorescein disulfide-bovine ... More
1-Anilino-8-naphthalenesulfonate: a fluorescent indicator of ion binding electrostatic potential on the membrane surface.
AuthorsHaynes DH
JournalJ Membr Biol
PubMed ID4847764
Structural defects underlying protein dysfunction in human glucose-6-phosphate dehydrogenase A(-) deficiency.
AuthorsGómez-Gallego F, Garrido-Pertierra A, Bautista JM
JournalJ Biol Chem
PubMed ID10734064
'The enzyme variant glucose-6-phosphate dehydrogenase (G6PD) A(-), which gives rise to human glucose-6-phosphate dehydrogenase deficiency, is a protein of markedly reduced structural stability. This variant differs from the normal enzyme, G6PD B, in two amino acid substitutions. A further nondeficient variant, G6PD A, bears only one of these two mutations ... More
Interaction of 1,1'-bi(4-anilino)naphthalene-5,5'-disulfonic acid with alpha-crystallin.
AuthorsSharma KK, Kaur H, Kumar GS, Kester K
JournalJ Biol Chem
PubMed ID9535881
'The hydrophobic sites in alpha-crystallin were evaluated using a fluorescent probe 1,1''-bi(4-anilino)naphthalenesulfonic acid (bis-ANS). Approximately one binding site/subunit of alpha-crystallin at 25 degrees C was estimated by equilibrium binding and Scatchard analysis (Kd = 1.1 microM). Based on fluorescence titration, the dissociation constant was 0.95 microM. The number of bis-ANS ... More
8-Anilino-1-naphthalenesulfonate is a fluorescent probe of conformational changes in the D-galactose-H+ symport protein of Escherichia coli.
AuthorsWalmsley AR, Martin GE, Henderson PJ
JournalJ Biol Chem
PubMed ID8006005
'The binding of sugars and antibiotics to the overexpressed D-galactose-H+ symport protein (GalP) can be monitored from changes in the fluorescence of 8-anilino-1-naphthalenesulfonate (ANS) equilibrated with inside-out vesicles. Transported sugars, such as D-glucose and D-galactose, cause an enhancement in the ANS fluorescence of up to 13%. Nontransported sugars that have ... More
Mapping conformational changes in a protein: application of a protein footprinting technique to cAMP-induced conformational changes in cAMP receptor protein.
AuthorsBaichoo N, Heyduk T
JournalBiochemistry
PubMed ID9283073
'We have used protein footprinting [Heyduk, E., & Heyduk, T. (1994) Biochemistry 33, 9643] to detect and map ligand-induced conformational changes in cAMP receptor protein (CRP). The binding of cAMP to CRP dramatically increases the specific DNA binding activity of the protein and, as has been previously shown, induces conformational ... More
Hydrophobicity of the NADPH binding domain of camel lens zeta-crystallin.
AuthorsBazzi MD, Rabbani N, Duhaiman AS
JournalBiochim Biophys Acta
PubMed ID11257509
'Interaction of camel lens zeta-crystallin with the hydrophobic probe 1-anilinonaphthalene-8-sulfonic acid (ANS) enhanced the ANS fluorescence and quenched the protein fluorescence. Both of these events were concentration-dependent and showed typical saturation curves suggesting specific ANS-zeta-crystallin binding. Quantitative analysis indicated that 1 mole zeta-crystallin bound at most 1 mole ANS. NADPH ... More
Inhibition of carbonic anhydrase-II by sulfamate and sulfamide groups: an investigation involving direct thermodynamic binding measurements.
AuthorsKlinger AL, McComsey DF, Smith-Swintosky V, Shank RP, Maryanoff BE
JournalJ Med Chem
PubMed ID16759092
'This paper examines the relative effectiveness of bioisosteric sulfamate and sulfamide derivatives for inhibition of human carbonic anhydrase-II (CA-II) by using a direct binding assay based on the ThermoFluor method (Matulis et al. Biochemistry 2005, 44, 5258). Compounds 1-10, which represent five cognate sulfamate/sulfamide pairs, were studied by ThermoFluor to ... More
Amphipathic alpha-helix bundle organization of lipid-free chicken apolipoprotein A-I.
AuthorsKiss RS, Kay CM, Ryan RO
JournalBiochemistry
PubMed ID10194351
'Apolipoprotein A-I (apoA-I), the major protein component of plasma high-density lipoprotein (HDL), exists in alternate lipid-free and lipid-bound states. Among various species, chicken apoA-I possesses unique structural properties: it is a monomer in the lipid-free state and it is virtually the sole protein component of HDL. Near-UV circular dichroism (CD) ... More
The acid-induced state of glucose oxidase exists as a compact folded intermediate.
AuthorsHaq SK, Ahmad MF, Khan RH
JournalBiochem Biophys Res Commun
PubMed ID12659873
'A systematic investigation of the acid-induced unfolding of glucose oxidase (beta-D-glucose: oxygen 1-oxidoreductase) (GOD) from Aspergillus niger was made using steady-state tryptophan fluorescence, circular dichroism (CD), and ANS (1-anilino 8-naphthalene sulfonic acid) binding. Intrinsic tryptophan fluorescence studies showed a maximally unfolded state at pH 2.6 and the presence of a ... More
Intersubunit communications in Escherichia coli cyclic AMP receptor protein: studies of the ligand binding domain.
AuthorsHeyduk E, Heyduk T, Lee JC
JournalBiochemistry
PubMed ID1314647
'Escherichia coli cAMP receptor protein (CRP) is a homodimer in which each subunit is composed of two domains. The C-terminal domain is responsible for DNA recognition, whereas the larger N-terminal domain is involved in cAMP binding. Biochemical and genetic evidence suggests that both intersubunit and interdomain interactions play important roles ... More
Cooperative multiple binding of bisANS and daunomycin to tubulin.
AuthorsWard LD, Timasheff SN
JournalBiochemistry
PubMed ID7918408
'The binding of daunomycin and bisANS to tubulin was studied by direct equilibrium techniques. Both ligands generated abnormal Scatchard plots. Their concave-downward nature indicated positive cooperativity. The data conform to tubulin possessing ca. 35 daunomycin binding sites with a binding constant of 570-1430 M-1. The binding of bisANS is characterized ... More
Time-resolved fluorescence anisotropy study of the refolding reaction of the alpha-subunit of tryptophan synthase reveals nonmonotonic behavior of the rotational correlation time.
AuthorsBilsel O, Yang L, Zitzewitz JA, Beechem JM, Matthews CR
JournalBiochemistry
PubMed ID10194334
'Time-resolved fluorescence anisotropy of a bound extrinsic probe was studied in an effort to characterize dynamic properties of the transient partially folded forms that appear during the folding of the alpha-subunit of tryptophan synthase (alphaTS) from Escherichia coli. Previous studies have shown that alphaTS, a single structural domain, can be ... More
Inhibition of ADP-induced aggregation of bovine platelets by saturated fatty acids and its relation with the change of membrane surface charge.
AuthorsKitagawa S, Nishitama H, Kametani F
JournalBiochim Biophys Acta
PubMed ID6466668
'The inhibitory effects of saturated fatty acids with 4 to 18 carbon atoms on ADP-induced aggregation of bovine platelets were investigated. The inhibitory effects of the acids increased with increase of their alkyl chain length up to C14. On the other hand, from C16 the inhibitory effects tended to decrease ... More
A kinetic mechanism for the polymerization of alpha1-antitrypsin.
AuthorsDafforn TR, Mahadeva R, Elliott PR, Sivasothy P, Lomas DA
JournalJ Biol Chem
PubMed ID10092640
'The mutation in the Z deficiency variant of alpha1-antitrypsin perturbs the structure of the protein to allow a unique intermolecular linkage. These loop-sheet polymers are retained within the endoplasmic reticulum of hepatocytes to form inclusions that are associated with neonatal hepatitis, juvenile cirrhosis, and hepatocellular carcinoma. The process of polymer ... More
Nativelike structure and stability in a truncation mutant of a protein minidomain: the peripheral subunit-binding domain.
AuthorsSpector S, Young P, Raleigh DP
JournalBiochemistry
PubMed ID10194328
'Despite its small size, the peripheral subunit-binding domain from the dihydrolipoamide acetyltransferase component of the Bacillus stearothermophilus pyruvate dehydrogenase multienzyme complex adopts a unique, compact structure. To determine whether the full 43 residue sequence is required for the domain to adopt a stable, nativelike structure, 3 proteins of different lengths ... More
Electron paramagnetic resonance of spin-labeled aequorin.
AuthorsKemple MD, Ray BD, Jarori GK, Rao BD, Prendergast FG
JournalBiochemistry
PubMed ID6487606
'Aequorin is a Ca-activated bioluminescent protein from jellyfish. This protein contains two sulfhydryl groups, one of which is essential for its bioluminescence. Little information concerning the structure of and relationship between the metal binding sites of aequorin and the sulfhydryl group(s) is known. Aequorin was modified by attachment of either ... More
Mechanism of uptake of the fluorescent dye 2-(4-dimethylaminostyryl)-1-ethylpyridinium cation (DMP+) by phospholipid vesicles.
AuthorsSedgwick EG, Bragg PD
JournalBiochim Biophys Acta
PubMed ID8443217
'The fluorescent dye 2-(4-dimethylaminostyryl)-1-ethylpyridinium cation (DMP+) is taken up by liposomes of egg phosphatidylcholine in response to the imposition of a transmembrane potential. Entry of DMP+ into the bilayer driven by the transmembrane potential is accompanied by a change in the fluorescence emission maximum of the dye. This change reflects ... More
Metabolism of an anionic fluorescent dye, 1-anilino-8-naphthalene sulfonate (ANS) by rat liver microsomes.
AuthorsChung YB, Bae WT, Han K
JournalArch Pharm Res
PubMed ID9868536
'The present study was designed to examine the metabolism of 1-anilino-8-naphthalene sulfonate (ANS), an anionic compound which is transported into liver via "multispecific organic anion transporter", with rat hepatic microsomes. TLC analysis indicated that the fluorescent metabolites were not produced to a measurable extent, which made it possible to assess ... More
Detection of conformational changes in chloroplast coupling factor 1 by 8-anilino-1-naphthalene-sulphonate fluorescence changes.
AuthorsPick U, Finel M
JournalEur J Biochem
PubMed ID6225641
'Chloroplast coupling factor 1 (CF1) contains a high-affinity binding site for 8-anilino-1-napthalene sulphonate (ANS,Kd = 5-6 microM). The binding of ANS to the enzyme is associated with a fluorescence enhancement and a blue-shift in the emission spectrum. ANS only slightly inhibits ATP hydrolysis by CF1. Adenine nucleotides and inorganic phosphate ... More
Aspartate-induced aminoacylase folding and forming of molten globule.
AuthorsXie Q, Guo T, Wang T, Lu J, Zhou HM
JournalInt J Biochem Cell Biol
PubMed ID12824065
'Aspartate is an osmolyte found in some marine invertebrates and cyclostome fish. The aspartate-induced unfolding of N-acylamino acid amido hydrolase (aminoacylase) has been studied by measuring enzyme activity, fluorescence emission spectra, 8-anilino-1-naphthalenesulfonate (ANS) fluorescence spectra and far-UV circular dichroism (CD) spectra. The results showed that aspartate caused the inactivation and ... More
ATP and the core "alpha-Crystallin" domain of the small heat-shock protein alphaB-crystallin.
AuthorsMuchowski PJ, Hays LG, Yates JR, Clark JI
JournalJ Biol Chem
PubMed ID10514509
'Electrospray ionization mass spectrometry (ESI-LC/MS) of tryptic digests of human alphaB-crystallin in the presence and absence of ATP identified four residues located within the core "alpha-crystallin" domain, Lys(82), Lys(103), Arg(116), and Arg(123), that were shielded from the action of trypsin in the presence of ATP. In control experiments, chymotrypsin was ... More
The guanidine like effects of arginine on aminoacylase and salt-induced molten globule state.
AuthorsXie Q, Guo T, Lu J, Zhou HM
JournalInt J Biochem Cell Biol
PubMed ID14643894
'Aminoacylase is a dimeric enzyme containing one Zn(2+) ion per subunit. The arginine (Arg)-induced unfolding of Holo-aminoacylase and Apo-aminoacylase has been studied by measurement of enzyme activity, fluorescence emission spectra and 1-anilino-8-naphthalenesulfonate (ANS) fluorescence spectra. Besides being the most alkaline amino acid, the arginine molecule contains a positively charged guanidine ... More
Thioridazine interacts with the membrane of mitochondria acquiring antioxidant activity toward apoptosis--potentially implicated mechanisms.
AuthorsRodrigues T, Santos AC, Pigoso AA, Mingatto FE, Uyemura SA, Curti C
JournalBr J Pharmacol
PubMed ID11976278
'We evaluated the effects of the phenothiazine derivative thioridazine on mechanisms of mitochondria potentially implicated in apoptosis, such as those involving reactive oxygen species (ROS) and cytochrome c release, as well as the involvement of drug interaction with mitochondrial membrane in these effects. Within the 0 - 100 microM range ... More
Fluorescence polarization study on the increase of membrane fluidity of human erythrocyte ghosts induced by synthetic water-soluble polymers.
AuthorsOhno H, Shimidzu N, Tsuchida E, Sasakawa S, Honda K
JournalBiochim Biophys Acta
PubMed ID7317393
'The effect of water-soluble polymers on the membrane fluidity of human erythrocyte ghosts was investigated and was compared with that of concanavalin A by means of the fluorescence polarization technique. 8-Anilino-1-naphthalene sulfonic acid sodium salt and 1,6-diphenyl-1,3,5-hexatriene were used as probe molecules. The membrane fluidity was increased by the addition ... More
The folding of dimeric cytoplasmic malate dehydrogenase. Equilibrium and kinetic studies.
AuthorsSanyal SC, Bhattacharyya D, Das Gupta C
JournalEur J Biochem
PubMed ID12153583
'Porcine heart cytoplasmic malate dehydrogenase (s-MDH) is a dimeric protein (2 x 35 kDa). We have studied equilibrium unfolding and refolding of s-MDH using activity assay, fluorescence, far-UV and near-UV circular dichroism (CD) spectroscopy, hydrophobic probe-1-anilino-8-napthalene sulfonic acid binding, dynamic light scattering, and chromatographic (HPLC) techniques. The unfolding and refolding ... More
An insight into domain structures and thermal stability of gamma-crystallins.
AuthorsSen AC, Walsh MT, Chakrabarti B
JournalJ Biol Chem
PubMed ID1601859
'The thermal behavior of gamma II, gamma IIIA, gamma IIIB, and gamma IVA crystallin, from calorimetric and spectral studies, has been analyzed in terms of selective unfolding of domains, interdomain interactions, conformational stability, and the existence of intermediates in the order-disorder transition equilibrium. The major endothermic transition (Tm) observed calorimetrically ... More
Localization of the thrombin-binding domain on prothrombin fragment 2.
AuthorsLiaw PC, Fredenburgh JC, Stafford AR, Tulinsky A, Austin RC, Weitz JI
JournalJ Biol Chem
PubMed ID9535876
'Co-crystallographic studies have shown that the interaction of human prothrombin fragment 2 (F2) with thrombin involves the formation of salt bridges between the kringle inner loop of F2 and anion-binding exosite II of thrombin. When F2 binds to thrombin, it has been shown to evoke conformational changes at the active ... More
Probing of DNA-binding sites of Escherichia coli RecA protein utilizing 1-anilinonaphthalene-8-sulfonic acid.
AuthorsMasui R, Kuramitsu S
JournalBiochemistry
PubMed ID9724525
'RecA protein of Escherichia coli plays an essential role in homologous recombination of DNA strands. To analyze the interaction of RecA with single-stranded DNA (ssDNA), we performed a fluorescence competition assay employing 1-anilinonaphthalene-8-sulfonic acid (ANS) as an extrinsic fluorescent probe. ANS bound to RecA at three sites, leading to enhancement ... More
The lipid-free structure of apolipoprotein A-I: effects of amino-terminal deletions.
'Deletion mutants of human apolipoprotein A-I (apo hA-I) have been produced from a bacterial expression system to explore the function of the specific domains comprising residues 1-43, 1-65, 88-98, and 187-243, respectively, in the lipid-free conformation and in the lipid-binding mechanism of apo hA-I. Initial studies on apo Delta(1-43)A-I and ... More
Automated flow injection gradient technique for binding studies of micromolecules to proteins using potentiometric sensors: application to bovine serum albumin with anilinonaphthalenesulfonate probe and drugs.
AuthorsGeorgiou ME, Georgiou CA, Koupparis MA
JournalAnal Chem
PubMed ID10405613
'An automated flow injection (FI) gradient technique is described for the binding study of the potentiometric probe 1-anilino-8-naphthalenesulfonate (ANS) to bovine serum albumin (BSA). Using a single-channel FI system with a mixing chamber and a flow ANS electrode, the binding parameters (binding constant and number of binding sites) were calculated ... More
Salt modulates the stability and lipid binding affinity of the adipocyte lipid-binding proteins.
AuthorsSchoeffler AJ, Ruiz CR, Joubert AM, Yang X, LiCata VJ
JournalJ Biol Chem
PubMed ID12794068
'Adipocyte lipid-binding protein (ALBP or aP2) is an intracellular fatty acid-binding protein that is found in adipocytes and macrophages and binds a large variety of intracellular lipids with high affinity. Although intracellular lipids are frequently charged, biochemical studies of lipid-binding proteins and their interactions often focus most heavily on the ... More
Kinetics of folding of the all-beta sheet protein interleukin-1 beta.
'The folding of the all-beta sheet protein, interleukin-1 beta, was studied with nuclear magnetic resonance (NMR) spectroscopy, circular dichroism, and fluorescence. Ninety percent of the beta structure present in the native protein, as monitored by far-ultraviolet circular dichroism, was attained within 25 milliseconds, correlating with the first kinetic phase determined ... More
Differential temperature-dependent chaperone-like activity of alphaA- and alphaB-crystallin homoaggregates.
AuthorsDatta SA, Rao CM
JournalJ Biol Chem
PubMed ID10574947
'alpha-Crystallin, a heteromultimeric protein made up of alphaA- and alphaB-crystallins, functions as a molecular chaperone in preventing the aggregation of proteins. We have shown earlier that structural perturbation of alpha-crystallin can enhance its chaperone-like activity severalfold. The two subunits of alpha-crystallin have extensive sequence homology and individually display chaperone-like activity. ... More
The effect of tryptophanyl substitution on folding and structure of myoglobin.
AuthorsSirangelo I, Tavassi S, Martelli PL, Casadio R, Irace G
JournalEur J Biochem
PubMed ID10866792
'Mammalian myoglobins contain two tryptophanyl residues at the invariant positions 7 (A-5) and 14 (A-12) in the N-terminal region (A helix) of the protein molecule. The crucial role of tryptophanyl residues has been investigated by site-directed mutagenesis and molecular dynamics simulation. The apomyoglobin mutants with a double W-->F substitution were ... More
The crystallographic structure of phytohemagglutinin-L.
'The structure of phytohemagglutinin-L (PHA-L), a leucoagglutinating seed lectin from Phaseolus vulgaris, has been solved with molecular replacement using the coordinates of lentil lectin as model, and refined at a resolution of 2.8 A. The final R-factor of the structure is 20.0%. The quaternary structure of the PHA-L tetramer differs ... More
Transport of organic anions through the erythrocyte membrane as K+-valinomycin complexes.
AuthorsMarinetti GV, Skarin A, Whitman P
JournalJ Membr Biol
PubMed ID660643
'K+, Rb+, or Cs+ complexes of valinomycin form ion pair complexes with picric acid and trinitrobenzenesulfonate (TNBS). The formation of a picrate-K+-valinomycin complex is supported by spectral evidence. These complexes have zero net charge and readily permeate the intact erythrocyte membrane. The K+-valinomycin complex has been used to convert the ... More
A phosphorylation-induced major structural change in the N-terminal domain of the P protein of Chandipura virus.
AuthorsRaha T, Chattopadhyay D, Chattopadhyay D, Roy S
JournalBiochemistry
PubMed ID10026294
'It has previously been shown that phosphorylation of P protein of vesicular stomatitis virus as well as Chandipura (CHP) virus is required for transcription activation and replication switch. The structural nature of this crucial conformational change, however, is largely unknown. We have studied the phosphorylation-associated conformational change in the P ... More
Staining with ANS fluorescent dye reveals distribution of mitochondria and lipid droplets in cultured Leydig cells.
AuthorsBilinska B
JournalFolia Histochem Cytobiol
PubMed ID8026598
'After 1-anilinonaphthalene-8-sulphonate (ANS) staining two types of structures (spherical and elongated) were observed in the cytoplasm of Leydig cells. The spherical structures were predominantly localized in the perinuclear area, whereas the elongated forms were rather noticed in peripheral cytoplasm as well as in cellular processes. Comparison of the obtained pictures ... More
Fluorescence studies of the aged erythrocyte membranes.
AuthorsTozzi-Ciancarelli MG, D'Alfonso A, Tozzi E, Troiani-Sevi E, De Matteis G
JournalCell Mol Biol
PubMed ID2731189
'The most important purpose of this research is to characterize by means of fluorescence polarization the structural and functional changes which occur in the membrane of the human erythrocytes during aging process. Our results provide evidence of a significant increase of membrane fluidity in the deep lipid core and in ... More
GroEL binds artificial proteins with random sequences.
AuthorsAoki K, Motojima F, Taguchi H, Yomo T, Yoshida M
JournalJ Biol Chem
PubMed ID10788496
'Chaperonin GroEL from Escherichia coli binds to the non-native states of many unrelated proteins, and GroEL-recognizable structural features have been argued. As model substrate proteins of GroEL, we used seven artificial proteins (138 approximately 141 residues), each of which has a unique but randomly chosen amino acid sequence and no ... More
Properties of cremophor EL micelles probed by fluorescence.
AuthorsKessel D
JournalPhotochem Photobiol
PubMed ID1454875
'Using 1-anilino,8-naphthalenesulfonic acid (ANS) as a probe, we examined properties of micelles of Cremophor EL, an amphipathic agent which can solubilize hydrophobic photosensitizing agents and promote their distribution to plasma lipoprotein. In aqueous solution, Cremophor micelles persisted for several hours after dilution below the critical micellar concentration (CMC). After equilibrium ... More
Mechanism of protein-induced membrane fusion: fusion of phospholipid vesicles by clathrin associated with its membrane binding and conformational change.
AuthorsMaezawa S, Yoshimura T, Hong K, Düzgünes N, Papahadjopoulos D
JournalBiochemistry
PubMed ID2496757
'The clathrin-induced fusion of liposome membranes, the membrane binding of clathrin, and the conformational states of clathrin were investigated over a wide pH range using large unilamellar and multilamellar vesicles composed of phosphatidylserine (PS), phosphatidylcholine (PC), PS/PC (2:1), PS/PC (1:1), or PS/PC (1:2). The pH profiles of clathrin-induced fusion of ... More
Protein stability induced by ligand binding correlates with changes in protein flexibility.
AuthorsCelej MS, Montich GG, Fidelio GD
JournalProtein Sci
PubMed ID12824495
'The interaction between ligands and proteins usually induces changes in protein thermal stability with modifications in the midpoint denaturation temperature, enthalpy of unfolding, and heat capacity. These modifications are due to the coupling of unfolding with binding equilibrium. Furthermore, they can be attained by changes in protein structure and conformational ... More
Effects of C-terminal deletions on the conformational state and denaturation of phosphoglycerate kinase.
AuthorsMas MT, Chen HH, Aisaka K, Lin LN, Brandts JF
JournalBiochemistry
PubMed ID7794905
'Phosphoglycerate kinase (PGK) contains two domains of approximately equal size, both of the alpha/beta type. An alpha-helix consisting of the middle section of the 415-amino acid polypeptide chain, and the N- and C-termini reside in the interdomain hinge region [Watson, H. C., et al. (1982) EMBO J. 1, 1635-1640]. The ... More
Heparin prevents the binding of phospholipase A2 to phospholipid micelles: importance of the amino-terminus.
AuthorsDiccianni MB, Lilly-Stauderman M, McLean LR, Balasubramaniam A, Harmony JA
JournalBiochemistry
PubMed ID1892820
'The activity of the major isoform of porcine pancreatic phospholipase A2 (PLA2), designated B-PLA2, against micellar substrates is inhibited by heparin. Inhibition is a consequence of binding of the enzyme to heparin, documented by a heparin-induced alteration in the intrinsic fluorescence of B-PLA2 and in the 8-anilino-1-naphthalene sulfonate fluorescence and ... More
pH and temperature-induced molten globule-like denatured states of equinatoxin II: a study by UV-melting, DSC, far- and near-UV CD spectroscopy, and ANS fluorescence.
AuthorsPoklar N, Lah J, Salobir M, Macek P, Vesnaver G
JournalBiochemistry
PubMed ID9398152
'Thermal denaturation of equinatoxin II (EqTxII) in glycine buffer solutions (pH 1.1, 2.0, 3.0, and 3.5) and in triple distilled water (pH 5.5-6.0) was examined by differential scanning calorimetry, UV and CD spectroscopy and fluorescence emission spectroscopy of the added hydrophobic fluorescent probe ANS. At pH 5.5-6.0 and at temperatures ... More
Spectroscopic study of the activation and oligomerization of the channel-forming toxin aerolysin: identification of the site of proteolytic activation.
Authorsvan der Goot FG, Lakey J, Pattus F, Kay CM, Sorokine O, Van Dorsselaer A, Buckley JT
JournalBiochemistry
PubMed ID1382579
'The channel-forming protein aerolysin is secreted as a protoxin which can be activated by proteolytic removal of a C-terminal peptide. The activation and subsequent oligomerization of aerolysin were studied using a variety of spectroscopic techniques. Mass spectrometric determination of the molecular weights of proaerolysin and aerolysin permitted identification of the ... More
The location of fluorescence probes with charged groups in model membranes.
AuthorsKachel K, Asuncion-Punzalan E, London E
JournalBiochim Biophys Acta
PubMed ID9814853
'The location of commonly used charged fluorescent membrane probes in membranes was determined in order to: (1) investigate the relationship between the structure of hydrophobic molecules and their depth within membranes; and (2) aid interpretation of experiments in which these fluorescent probes are used to examine membrane structure. Membrane depth ... More
Fluorescence study on the interaction of a multiple antigenic peptide from hepatitis A virus with lipid vesicles.
AuthorsOrtiz A, Cajal Y, Haro I, Reig F, Alsina MA
JournalBiopolymers
PubMed ID10775061
'The interaction of the multiple antigenic peptide MAP4VP3 with lipid membranes has been studied by spectroscopic techniques. MAP4VP3 is a multimeric peptide that corresponds to four units of the sequence 110-121 of the capsid protein VP3 of hepatitis A virus. In order to evaluate the electrostatic and hydrophobic components on ... More
Fast folding of a four-helical bundle protein.
AuthorsMarianayagam NJ, Khan F, Male L, Jackson SE
JournalJ Am Chem Soc
PubMed ID12175232
'The FK506-FKBP12 binding-domain of the kinase FRAP (FRB) forms a classic up-down four-helical bundle. The folding pathway of this protein has been investigated using a combination of equilibrium and kinetic studies. The native state of the protein is stable with respect to the unfolded state by some 7 kcal mol(-1) ... More
Resolution of tryptophan-ANS fluorescence energy transfer in apomyoglobin by site-directed mutagenesis.
AuthorsSirangelo I, Malmo C, Casillo M, Irace G
JournalPhotochem Photobiol
PubMed ID12405143
'Resonance energy transfer between tryptophanyl residues and the apolar fluorescent dye 1-anilino-8-naphthalene sulfonate (ANS) occurs when the fluorophore is bound to native folded sperm whale apomyoglobin. The individual transfer contribution of the two tryptophanyl residues (W7 and W14, both located on the A-helix of the protein) was resolved by measuring ... More
Effect of self-association on the structural organization of partially folded proteins: inactivated actin
'The propensity to associate or aggregate is one of the characteristic properties of many nonnative proteins. The aggregation of proteins is responsible for a number of human diseases and is a significant problem in biotechnology. Despite this, little is currently known about the effect of self-association on the structural properties ... More
The effect of conserved residue charge reversal on the folding of recombinant non-phosphorylated human beta-casein.
AuthorsBu H, Sood SM, Slattery CW
JournalArch Biochem Biophys
PubMed ID14592468
'A short stretch of 13 amino acids in the central portion of human beta-casein contains four positively charged conserved residues, three Lys and one Arg. We changed these individually to Glu, reversing their charge, and compared the resulting recombinant proteins to the wild-type recombinant, monitoring thermal aggregation with turbidity as ... More
Kinetic partitioning. Poising SecB to favor association with a rapidly folding ligand.
AuthorsDiamond DL, Randall LL
JournalJ Biol Chem
PubMed ID9360972
'Chaperones are a class of proteins that possess the remarkable ability to selectively bind polypeptides that are in a nonnative state. The selectivity of SecB, a molecular chaperone in Escherichia coli, for its ligands can be explained in part by a kinetic partitioning between folding of the polypeptide and association ... More
Time-resolved total internal reflection fluorometry study on polarity at a liquid/liquid interface.
AuthorsIshizaka S, Kim HB, Kitamura N
JournalAnal Chem
PubMed ID11403281
'The polarity of a water/oil (oil: cyclohexane, carbon tetrachloride, toluene, chlorobenzene, o-dichlorobenzene, or 1,2-dichloroethane) interface was investigated by means of time-resolved total-internal-reflection (TIR) fluorescence spectroscopy of a polarity-sensitive probe: sulforhodamine B (SRB). In bulk solutions, the nonradiative decay rate constant of SRB increased with an increase in a solvent polarity ... More
Direct binding of ethanol to bovine serum albumin: a fluorescent and 13C NMR multiplet relaxation study.
AuthorsAvdulov NA, Chochina SV, Daragan VA, Schroeder F, Mayo KH, Wood WG
JournalBiochemistry
PubMed ID8555194
'Molecular mechanisms of ethanol interaction with proteins are not well-understood. In the present study, direct interaction of ethanol with hydrophobic binding sites on fatty acid free bovine serum albumin (BSA) was determined using the fluorescent probe 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS), cis-parinaric acid, and 13C NMR. The affinity of ethanol for BSA ... More
Native-like conformations are sampled by partially folded and disordered variants of bovine pancreatic trypsin inhibitor.
AuthorsTulla-Puche J, Getun IV, Woodward C, Barany G
JournalBiochemistry
PubMed ID14769035
'Partially folded conformational ensembles of bovine pancreatic trypsin inhibitor (BPTI) are accessed by replacing Cys 5, 30, 51, and 55 by alpha-amino-n-butyric acid (Abu) while retaining the disulfide between Cys 14 and 38; the resultant variant is termed [14-38](Abu). Two new analogues with modifications in the beta-turn, P26D27[14-38](Abu) and N26G27K28[14-38](Abu), ... More
Reactions of fluorescent probes with normal and chemically modified myelin.
AuthorsFeinstein MB, Felsenfeld H
JournalBiochemistry
PubMed ID238581
'The fluorescent probes 8-anilino-1-naphthalenesulfonate (ANS) and 2-p-toluidinylnaphthalene-6-sulfonate (TNS) bind to highly purified myelin membranes obtained from bovine brain white matter. Binding of the dyes was markedly increased by environmental conditions which reduce the negative surface potential of the membrane, i.e., cations (La-3+ is greater than Ca-2+ is greater than Na-+,K-+), ... More
Implications of the ligandin binding site on the binding of non-substrate ligands to Schistosoma japonicum-glutathione transferase.
AuthorsYassin Z, Ortiz-Salmerón E, García-Maroto F, Barón C, García-Fuentes L
JournalBiochim Biophys Acta
PubMed ID15134656
'The binding interactions between dimeric glutathione transferase from Schistosoma japonicum (Sj26GST) and bromosulfophthalein (BS) or 8-anilino-1-naphthalene sulfonate (ANS) were characterised by fluorescence spectroscopy and isothermal titration calorimetry (ITC). Both ligands inhibit the enzymatic activity of Sj26GST in a non-competitive form. A stoichiometry of 1 molecule of ligand per mole of ... More
Structure and thermodynamics of the extraordinarily stable molten globule state of canine milk lysozyme.
AuthorsKoshiba T, Yao M, Kobashigawa Y, Demura M, Nakagawa A, Tanaka I, Kuwajima K, Nitta K
JournalBiochemistry
PubMed ID10727216
'Here, we show that an unfolded intermediate of canine milk lysozyme is extraordinarily stable compared with that of the other members of the lysozyme-alpha-lactalbumin superfamily, which has been studied previously. The stability of the intermediate of this protein was investigated using calorimetry, CD spectroscopy, and NMR spectroscopy, and the results ... More
Activation of protein kinase C by short chain phosphatidylcholines.
AuthorsWalker JM, Sando JJ
JournalJ Biol Chem
PubMed ID3350802
'The acidic phospholipid requirement for protein kinase C (Ca2+/phospholipid-dependent enzyme) activation has been well established, although the molecular nature of this lipid-protein interaction is unclear. The additional requirement for Ca2+ has provided the basis for several models involving charge interactions. We now report that short chain neutral phosphatidylcholines also activate ... More
Ca(2+)- and H(+)-dependent conformational changes of calbindin D(28k).
AuthorsBerggård T, Silow M, Thulin E, Linse S
JournalBiochemistry
PubMed ID10841767
'Calbindin D(28k) is a member of a large family of intracellular Ca(2+) binding proteins characterized by EF-hand structural motifs. Some of these proteins are classified as Ca(2+)-sensor proteins, since they are involved in transducing intracellular Ca(2+) signals by exposing a hydrophobic patch on the protein surface in response to Ca(2+) ... More
Fluorescent probing of the ligand-binding ability of blood plasma in the acute-phase response.
'The acute-phase response alters the composition of carrier proteins in plasma, which may affect the blood deposition and transport of biomediators and drugs. The effect of the acute-phase response on the ligand binding ability of plasma was studied in leukemic children with and without systemic inflammation (sepsis and septic shock). ... More
Matrix proteins from insect pliable cuticles: are they flexible and easily deformed?
AuthorsAndersen SO
JournalInsect Biochem Mol Biol
PubMed ID11222954
'Proteins from pliable cuticle of locusts, Schistocerca gregaria, and silk moth larvae, Hyalophora cecropia, were studied in solution by means of a fluorescent probe, 8-anilinonaphthalene-1-sulphonic acid (ANS), which is much more fluorescent in non-polar media than in polar media. An intense ANS-fluorescence was observed in the presence of the cuticular ... More
Interactions of soluble penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus with moenomycin.
AuthorsGraves-Woodward K, Pratt RF
JournalBiochemistry
PubMed ID10441150
'Kinetics studies in homogeneous aqueous solution showed that solubilized penicillin-binding protein 2a (sPBP2a) of methicillin-resistant Staphylococcus aureus (a bacterial DD-peptidase) was inhibited by the amphiphilic glycolipid antibiotic moenomycin. Inhibition at the peptidase site was determined by competition experiments between moenomycin and the chromophoric beta-lactam nitrocefin. Under conditions of high salt ... More
High-density miniaturized thermal shift assays as a general strategy for drug discovery.
AuthorsPantoliano MW, Petrella EC, Kwasnoski JD, Lobanov VS, Myslik J, Graf E, Carver T, Asel E, Springer BA, Lane P, Salemme FR
JournalJ Biomol Screen
PubMed ID11788061
'More general and universally applicable drug discovery assay technologies are needed in order to keep pace with the recent advances in combinatorial chemistry and genomics-based target generation. Ligand-induced conformational stabilization of proteins is a well-understood phenomenon in which substrates, inhibitors, cofactors, and even other proteins provide enhanced stability to proteins ... More
Fluorescence spectroscopic investigations of the dynamic properties of proteins, membranes and nucleic acids.
AuthorsLakowicz JR
JournalJ Biochem Biophys Methods
PubMed ID6158533
'Fluorescence spectroscopy can reveal the dynamic properties of proteins, membranes and nucleic acids on the nanosecond timescale. Dynamic processes which can affect the fluorescence spectral characteristics of biopolymer-bound fluorophores include dipolar relaxation around excited state dipoles, rotational diffusion of fluorophores, and permeation of bipolymers of fluorescence quenchers. The occurrence of ... More
Molecular dynamics of hemoglobin subunits as seen by fluorescence spectroscopy.
AuthorsOton J, Bucci E, Steiner RF, Fronticelli C, Franchi D, Montemarano J, Martinez A
JournalJ Biol Chem
PubMed ID7251596
'Fluorescent conjugates of beta A subunits and their respective heme-free derivatives have been prepared in which a 1,5-N-iodoacetylaminoethyl-5-naphthylamine-1-sulfonate probe has been specifically placed at the beta-93 or beta-112 cysteine. The fluorescence anisotropy decay and static fluorescence polarization of these conjugates have been examined. Fluorescence measurements have also been made using ... More
Anisodamine causes the changes of structure and function in the transmembrane domain of the Ca(2+)-ATPase from sarcoplasmic reticulum.
AuthorsPang YH, Chen JW
JournalBiosci Biotechnol Biochem
PubMed ID14745174
'The effects of anisodamine on the Ca(2+)-ATPsae of sarcoplasmic reticulum (SR) were investigated by using differential scanning calorimetry to measure the ability of anisodamine to denature the transmembrane domain and the cytoplasmic domain. Anisodamine significantly altered the thermotropic phase behaviors of the transmembrane domain of purified Ca(2+)-ATPase. Specifically, the melting ... More
Identification of 1,1'-bi(4-anilino)naphthalene-5,5'-disulfonic acid binding sequences in alpha-crystallin.
AuthorsSharma KK, Kumar GS, Murphy AS, Kester K
JournalJ Biol Chem
PubMed ID9624133
'The hydrophobic binding sites in alpha-crystallin were evaluated using fluorescent probes 1,1''-bi(4-anilino)naphthalenesulfonic acid (bis-ANS), 8-anilino-1-naphthalene sulfonate (ANS), and 1-azidonaphthalene 5-sulfonate (1,5-AZNS). The photolysis of bis-ANS-alpha-crystallin complex resulted in incorporation of the probe to both alphaA- and alphaB-subunits. Prior binding of denatured alcohol dehydrogenase to alpha-crystallin significantly decreased the photoincorporation of ... More
Effect of beta-Cyclodextrin on the Photoinduced Charge Transfer in Sodium 1-Anilino-8-naphthalene Sulfate (ANS)/CdS Colloidal System.
AuthorsYang J, Xiang J, Chen C, Lu D, Xu G
JournalJ Colloid Interface Sci
PubMed ID11482950
'The S-center radical (ANS(.)) of sodium 1-anilino-8-naphthalene sulfate (ANS) generated by photoinduced charge transfer in ANS/CdS and ANS/CdS/beta-cyclodextrin(beta-CD) systems has been studied by using spin trapping electron spin resonance techniques, UV-visible spectroscopic methods, and fluorescence spectroscopic methods. It was found that the S-centered radical (ANS(.)) was produced by the charge ... More
Hydrophobic probe binding of beta-lactoglobulin in the native and molten globule state induced by high pressure as affected by pH, KIO(3) and N-ethylmaleimide.
AuthorsYang J, Powers JR, Clark S, Dunker AK, Swanson BG
JournalJ Agric Food Chem
PubMed ID12188631
'High hydrostatic pressure (HHP) at 500 MPa and 50 degrees C induces beta-LG into the molten globule state. Retinol, cis-parinaric acid (CPA), and 1-anilino-naphthalene-8-sulfonate (ANS) fluorescence from pH 2.5 to 10.5 in the presence of the native and molten globule states of beta-LG indicate that retinol binds to beta-LG in ... More
High hydrostatic pressure perturbs the interactions between CF(0)F(1) subunits and induces a dual effect on activity.
AuthorsSouza MO, Creczynski-Pasa TB, Scofano HM, Gräber P, Mignaco JA
JournalInt J Biochem Cell Biol
PubMed ID15006644
'Chloroplast ATP-synthase is an H(+)/ATP-driven rotary motor in which a hydrophobic multi-subunit assemblage rotates within a hydrophilic stator, and subunit interactions dictate alternate-site catalysis. To explore the relevance of these interactions for catalysis we use hydrostatic pressure to induce conformational changes and/or subunit dissociation, and the resulting changes in the ... More
cDNA cloning, expression, and mutagenesis of a PR-10 protein SPE-16 from the seeds of Pachyrrhizus erosus.
AuthorsWu F, Yan M, Li Y, Chang S, Song X, Zhou Z, Gong W
JournalBiochem Biophys Res Commun
PubMed ID14680830
'SPE-16 is a new 16kDa protein that has been purified from the seeds of Pachyrrhizus erosus. It''s N-terminal amino acid sequence shows significant sequence homology to pathogenesis-related class 10 proteins. cDNA encoding 150 amino acids was cloned by RT-PCR and the gene sequence proved SPE-16 to be a new member ... More
Domain swapping in human alpha A and alpha B crystallins affects oligomerization and enhances chaperone-like activity.
AuthorsKumar LV, Rao CM
JournalJ Biol Chem
PubMed ID10896951
'alphaA and alphaB crystallins, members of the small heat shock protein family, prevent aggregation of proteins by their chaperone-like activity. These two proteins, although very homologous, particularly in the C-terminal region, which contains the highly conserved "alpha-crystallin domain," show differences in their protective ability toward aggregation-prone target proteins. In order ... More
Fluorescence spectroscopic studies of Huntington fibroblast membranes.
AuthorsLakowicz JR, Sheppard JR
JournalAm J Hum Genet
PubMed ID6452057
'Using fluorescence spectroscopic methods, we compared the membrane properties of intact fibroblasts from both normal subjects and patients with Huntington disease (HD). Cells were stained with various fluorophores, including 1-anilino-8-naphthalene sulfonic acid (ANS), 2-toluidinyl-6-naphthalene sulfonic acid (TNS), 1,6-diphenyl-1,3,5-hexatriene (DPH), and 6-lauroyl-2-(dimethylamino)-naphthalene (LAURDAN). Using these labeled cells, we measured fluorescence yields ... More
A collapsed intermediate with nonnative packing of hydrophobic residues in the folding of TEM-1 beta-lactamase.
AuthorsVanhove M, Lejeune A, Guillaume G, Virden R, Pain RH, Schmid FX, Frère JM
JournalBiochemistry
PubMed ID9485321
'The kinetics of refolding of TEM-1 beta-lactamase from solution in guanidine hydrochloride have been investigated on the manual and stopped-flow mixing time scales. The kinetics of change of far-UV circular dichroism and of intrinsic and ANS fluorescence have been compared with changes in the quenching of fluorescence by acrylamide as ... More
Evidence that a salt bridge in the light chain contributes to the physical stability difference between heavy and light human ferritins.
AuthorsSantambrogio P, Levi S, Arosio P, Palagi L, Vecchio G, Lawson DM, Yewdall SJ, Artymiuk PJ, Harrison PM, Jappelli R
JournalJ Biol Chem
PubMed ID1629207
'Human ferritin, a multimeric iron storage protein, is composed by various proportions of two subunit types: the H- and L-chains. The biological functions of these two genic products have not been clarified, although differences in reactivity with iron have been shown. Starting from the hypothesis that the high stability typical ... More
Effect of D57N mutation on membrane activity and molecular unfolding of cobra cardiotoxin.
'Cobra cardiotoxins (CTXs) are able to adopt a three-fingered beta-strand structure with continuous hydrophobic patch that is capable of interacting with zwitterionic phospholipid bilayer. In addition to the four disulfide bonds that form the rigid core of CTXs, Asp57 near the C-terminus interacts electrostatically with Lys2 near the N-terminus (Chiang ... More
H(+)-ATP synthase from rat liver mitochondria. A simple, rapid purification method of the functional complex and its characterization.
AuthorsYoshihara Y, Nagase H, Yamane T, Oka H, Tani I, Higuti T
JournalBiochemistry
PubMed ID1829963
'A novel, simple, and rapid preparative method for purification of rat liver H(+)-ATP synthase by anion-exchange HPLC was developed. The H(+)-ATP synthase purified had higher ATPase activity in the absence of added phospholipids than any preparation reported previously, and this activity was completely inhibited by oligomycin. When reconstituted into proteoliposomes, ... More
Characterization of the sources of protein-ligand affinity: 1-sulfonato-8-(1')anilinonaphthalene binding to intestinal fatty acid binding protein.
AuthorsKirk WR, Kurian E, Prendergast FG
JournalBiophys J
PubMed ID8770188
'1-Sulfonato-8-(1'')anilinonaphthalene (1,8-ANS) was employed as a fluorescent probe of the fatty acid binding site of recombinant rat intestinal fatty acid binding protein (1-FABP). The enhancement of fluorescence upon binding allowed direct determination of binding affinity by fluorescence titration experiments, and measurement of the effects on that affinity of temperature, pH, ... More
Lead ion effect on creatine kinase: equilibrium and kinetic studies of inactivation and conformational changes.
AuthorsZhou HW, Park YD, Zhou HM
JournalInt J Biochem Cell Biol
PubMed ID11906827
'The effects of lead ions on creatine kinase (CK) were studied by measuring activity changes, intrinsic fluorescence spectra and 8-anilo-1-naphthalenesulfonate (ANS)-binding fluorescence along with size-exclusion chromatography (SEC). Below 5 mM Pb(2+) concentration, there was nearly no change of the enzyme activity and a slight change of the ANS-binding fluorescence. The ... More
Exposure of hydrophobic surfaces on the chaperonin GroEL oligomer by protonation or modification of His-401.
AuthorsGibbons DL, Horowitz PM
JournalJ Biol Chem
PubMed ID7706275
'Hydrophobic exposure on the chaperonin GroEL is increased 6-10-fold after the protein is treated with the His-reactive reagent diethyl pyrocarbonate (DEP), or the solution pH is lowered to 5.5. The induced hydrophobic surfaces have the same 1,1''-bis(4-anilino)naphthalene-5,5''-disulfonic acid (bis-ANS) binding characteristics as unperturbed GroEL: a Kd approximately equal to 3.5 ... More
Calcium-dependent solvation of the myristoyl group of recoverin.
AuthorsHughes RE, Brzovic PS, Klevit RE, Hurley JB
JournalBiochemistry
PubMed ID7547868
'Recoverin is an N-myristoylated calcium-binding protein present in the photoreceptor cells of the mammalian retina. It is believed to function as a calcium sensor in visual signal transduction by coupling the kinetics of the recovery phase of the photoresponse to changes in the levels of intracellular Ca2+. Upon binding Ca2+, ... More
In vitro study on the interaction of mechanism of tricyclic compounds with bovine serum albumin.
AuthorsKamat BP, Seetharamappa J
JournalJ Pharm Biomed Anal
PubMed ID15137993
'The mechanism of interaction of five phenothiazine drugs with bovine serum albumin has been investigated using fluorescence spectroscopy, circular dichroism and equilibrium dialysis methods. It was found that the phenothiazine ring common to all drugs makes major contribution to interaction. However, the nature of alkylamino group at position 10 influences ... More
Mutation of R116C results in highly oligomerized alpha A-crystallin with modified structure and defective chaperone-like function.
AuthorsShroff NP, Cherian-Shaw M, Bera S, Abraham EC
JournalBiochemistry
PubMed ID10684623
'An autosomal dominant congenital cataract in human is associated with mutation of Arg-116 to Cys (R116C) in alpha A-crystallin. To investigate the molecular basis of cataract formation, rat alpha A-crystallin cDNA was cloned into pET-23d(+), and the site-directed mutants S142C (similar to wild-type human alpha A) and R116C/S142C or R116C ... More
Synthesis of a highly fluorescent beta-diketone-europium chelate and its utility in time-resolved fluoroimmunoassay of serum total thyroxine.
AuthorsWu FB, Han SQ, Zhang C, He YF
JournalAnal Chem
PubMed ID12463376
'A new highly fluorescent beta-diketone-europium chelate was synthesized and employed as a tracer to develop a time-resolved fluoroimmunoassay (TRFIA) for detection of serum total thyroxine (T4). The tetradentate beta-diketone chelator, 1,10-bis(thiophene-2''-yl)-4,4,5,5,6,6,7,7-octafluorodecane-1,3,8,10-tetraone (BTOT), was structurally composed of two units of thenoyltrifluoroacetone (TTA) derivatives but expressed fluorescence that was greatly enhanced, as ... More
Supramolecular ligands: monomer structure and protein ligation capability.
AuthorsStopa B, Górny M, Konieczny L, Piekarska B, Rybarska J, Skowronek M, Roterman I
JournalBiochimie
PubMed ID9924974
'The aim of this work was to define the chemical structure of compounds self-assembling in water solutions, which appear to interact with proteins as single ligands with their supramolecular nature preserved. For this purpose the ligation to proteins of bis azo dyes, represented by Congo red and its derivatives with ... More
The N-terminal sequence (residues 1-65) is essential for dimerization, activities, and peptide binding of Escherichia coli DsbC.
AuthorsSun XX, Wang CC
JournalJ Biol Chem
PubMed ID10930424
'Limited proteolysis of DsbC with trypsin resulted in a compact and stable C-terminal fragment (residues 66-216), fDsbC, which retains the active site sequence, -Cys(98)-Gly-Tyr-Cys(101)-, and shows only minor differences in conformation compared with that of the intact molecule. The pK(a) of active site thiol and the K(SS) with glutathione are ... More
Nondestructive detection of neutral glycosphingolipids with lipophilic anionic fluorochromes and their employment for preparative high-performance thin-layer chromatography.
AuthorsMüthing J, Kemminer SE
JournalAnal Biochem
PubMed ID8660611
'In this study a simple and effective procedure for the isolation of individual neutral glycosphingolipids (GSLs) by preparative thin-layer chromatography is described. The method is based on nondestructive visualization of neutral GSLs on silica gel precoated thin-layer chromatography plates with anionic lipophilic fluorochromes. After thin-layer chromatography, individual neutral GSLs were ... More
Unfolding pathway in red kidney bean acid phosphatase is dependent on ligand binding.
AuthorsCashikar AG, Rao NM
JournalJ Biol Chem
PubMed ID8617740
'Structural basis for ligand-induced protein stabilization was investigated in the case of an acid phosphatase (red kidney bean purple acid phosphatase (KBPAP)) from red kidney bean. Phosphate, a physiological ligand, increases the stability against solvent denaturation by 3.5 kcal/mol. Generality of phosphate stabilization was shown by similar effects with other ... More
Mutation of cysteine 254 facilitates the conformational changes accompanying the interconversion of persulfide-substituted and persulfide-free rhodanese.
AuthorsIslam TA, Miller-Martini DM, Horowitz PM
JournalJ Biol Chem
PubMed ID8132509
'Mutants of rhodanese (EC 2.8.1.1) that substitute Ser for Cys-254 and/or Cys-263, i.e. C254S, C263S, and the double mutant C254/263S, were compared with the wild-type enzyme to test the hypothesis that the persulfide formation to give sulfur-substituted rhodanese (ES) during catalysis can exert a stabilizing influence on the global structure ... More