The large size (six membrane-spanning repeats in each of four domains) and asymmetric architecture of the voltage-dependent Na+ channel has hindered determination of its structure. With the goal of determining the minimum structure of the Na+ channel permeation pathway, we created two stable cell lines expressing the voltage-dependent rat skeletal ... More
TRPC1 associates with BK(Ca) channel to form a signal complex in vascular smooth muscle cells.
AuthorsKwan HY, Shen B, Ma X, Kwok YC, Huang Y, Man YB, Yu S, Yao X,
JournalCirc Res
PubMed ID19168436
'TRPC1 (transient receptor potential canonical 1) is a Ca(2+)-permeable cation channel involved in diverse physiological function. TRPC1 may associate with other proteins to form a signaling complex, which is crucial for channel function. In the present study, we investigated the interaction between TRPC1 and large conductance Ca(2+)-sensitive K(+) channel (BK(Ca)). ... More
Na+-dependent release of Mg2+ from an intracellular pool in rat sublingual mucous acini.
AuthorsZhang GH, Melvin JE
JournalJ Biol Chem
PubMed ID8910560
'Muscarinic stimulation induces release of Mg2+ from an intracellular pool in rat sublingual mucous acini (Zhang, G. H., and Melvin, J. E. (1992) J. Biol. Chem. 267, 20721-20727). In the present study we examined the interdependence of Mg2+ mobilization on intracellular Na+ and Ca2+ by monitoring the intracellular free concentrations ... More
Activity of ionotropic glutamate receptors in retinal cells: effect of ascorbate/Fe(2+)-induced oxidative stress.
AuthorsAgostinho P, Duarte CB, Oliveira CR
JournalJ Neurochem
PubMed ID8752122
'The effect of oxidative stress induced by the oxidant pair ascorbate/Fe2+ on the activity of ionotropic glutamate receptors was studied in cultured chick retina cells. The release of [3H]GABA and the increase of the intracellular free Na+ concentration ([Na+]i), evoked by glutamate receptor agonists, were used as functional assays for ... More
Gramicidin channels in phospholipid bilayers with unsaturated acyl chains.
AuthorsGirshman J, Greathouse DV, Koeppe RE, Andersen OS
JournalBiophys J
PubMed ID9284299
'In organic solvents gramicidin A (gA) occurs as a mixture of slowly interconverting double-stranded dimers. Membrane-spanning gA channels, in contrast, are almost exclusively single-stranded beta(6,3)-helical dimers. Based on spectroscopic evidence, it has previously been concluded that the conformational preference of gA in phospholipid bilayers varies as a function of the ... More
Induction of cytosolic Ca2+ elevation mediated by Mas-7 occurs through membrane pore formation.
AuthorsSuh BC, Song SK, Kim YK, Kim KT
JournalJ Biol Chem
PubMed ID8955110
'Mas-7, a mastoparan derivative, induces elevation of intracellular free Ca2+ concentration ([Ca2+]i) along two independent pathways. The minor contribution occurs via phospholipase C activation and is negatively regulated by treatment with phorbol 12-myristate 13-acetate, a protein kinase C activator. The major contribution involves plasma membrane pores allowing not only Ca2+, ... More
Fluorescence measurement of intracellular sodium concentration in single Escherichia coli cells.
AuthorsLo CJ, Leake MC, Berry RM
JournalBiophys J
PubMed ID16227503
'The energy-transducing cytoplasmic membrane of bacteria contains pumps and antiports maintaining the membrane potential and ion gradients. We have developed a method for rapid, single-cell measurement of the internal sodium concentration ([Na(+)](in)) in Escherichia coli using the sodium ion fluorescence indicator, Sodium Green. The bacterial flagellar motor is a molecular ... More
Two mechanisms of H+/OH- transport across phospholipid vesicular membrane facilitated by gramicidin A.
AuthorsPrabhananda BS, Kombrabail MH
JournalBiophys J
PubMed ID8968580
'Two rate-limiting mechanisms have been proposed to explain the gramicidin channel facilitated decay of the pH difference across vesicular membrane (delta pH) in the pH region 6-8 and salt (MCI, M+ = K+, Na+) concentration range 50-300 mM. 1) At low pH conditions (approximately 6), H+ transport through the gramicidin ... More
Effect of gramicidin A on the dipole potential of phospholipid membranes.
AuthorsShapovalov VL, Kotova EA, Rokitskaya TI, Antonenko YN
JournalBiophys J
PubMed ID10388758
'The effect of channel-forming peptide gramicidin A on the dipole potential of phospholipid monolayers and bilayers has been studied. Surface pressure and surface potential isotherms of monolayers have been measured with a Langmuir trough equipped with a Wilhelmy balance and a surface potential meter (Kelvin probe). Gramicidin has been shown ... More
Synthesis of acylated gramicidins and the influence of acylation on the interfacial properties and conformational behavior of gramicidin A.
AuthorsVogt TC, Killian JA, Demel RA, De Kruijff B
JournalBiochim Biophys Acta
PubMed ID1718430
'Five gramicidin A analogs were synthesized in which various acyl chains, differing in length and unsaturation, were covalently coupled to the C-terminal ethanolamine group. The analogs were characterized by various spectroscopic techniques and their molecular properties were investigated using monolayer techniques and circular dichroism. It is demonstrated that neither the ... More
Intracellular potassium stabilizes human ether-à-go-go-related gene channels for export from endoplasmic reticulum.
AuthorsWang L, Dennis AT, Trieu P, Charron F, Ethier N, Hebert TE, Wan X, Ficker E,
JournalMol Pharmacol
PubMed ID19139152
'Several therapeutic compounds have been identified that prolong the QT interval on the electrocardiogram and cause torsade de pointes arrhythmias not by direct block of the cardiac potassium channel human ether-à-go-go-related gene (hERG) but via disruption of hERG trafficking to the cell surface membrane. One example of a clinically important ... More
Methodological aspects of measuring absolute values of membrane potential in human cells by flow cytometry.
AuthorsKlapperstück T, Glanz D, Klapperstück M, Wohlrab J,
JournalCytometry A
PubMed ID19504578
'The bis-barbituric acid oxonol, DiBAC(4)(3) is used as a standard potentiometric probe in human cells. However, its fluorescence depends not only on membrane potential but also varies with nonpotential related changes in the amount of intracellular free and bound dye. This study demonstrates the influence of different experimental conditions on ... More
Assessment of Escherichia coli B with enhanced permeability to fluorochromes for flow cytometric assays of bacterial cell function.
AuthorsHerrera G, Martinez A, Blanco M, O'Connor JE
JournalCytometry
PubMed ID12357461
'BACKGROUND: Flow cytometry has become a choice methodology for microbiological research. However, functional cytometric assays in live bacteria are still limited. This is due, in part, to the cell wall impairing penetration of vital dyes in bacteria, thus imposing permeabilization procedures. These manipulations may affect cell physiology, provoke cell aggregation ... More
Excitotoxic degeneration is initiated at non-random sites in cultured rat cerebellar neurons.
AuthorsBindokas VP, Miller RJ
JournalJ Neurosci
PubMed ID7472456
'Prolonged stimulation of cultured cerebellar neurons by kainic acid (KA) leads to death of neurons first evident from the swelling of soma and neurites. Stimulation is accompanied by increases in [Ca2+]i and [Na+]i as monitored using digital imaging microfluorimetry. "Blebs" tended to form on neurites with the highest increases in ... More
Regulatory volume decrease in HL-60 cells: importance of rapid changes in permeability of Cl- and organic solutes.
AuthorsHallows KR, Knauf PA
JournalAm J Physiol
PubMed ID7943267
'Results obtained through the use of inhibitors and isotope flux and equilibration techniques indicate that the regulatory volume decrease (RVD) response of human promyelocytic leukemic HL-60 cells occurs largely through the efflux of K+ and Cl- through separate conductive membrane pathways. These "channels" differ pharmacologically and in their modes of ... More
Structure and dynamics of hydronium in the ion channel gramicidin A.
AuthorsSagnella DE, Voth GA
JournalBiophys J
PubMed ID9172729
'The effects of the hydronium ion, H(3)0+, on the structure of the ion channel gramicidin A and the hydrogen-bonded network of waters within the channel were studied to help elucidate a possible mechanism for proton transport through the channel. Several classical molecular dynamics studies were carried out with the hydronium ... More
The ability of membrane potential dyes and calcafluor white to distinguish between viable and non-viable bacteria.
AuthorsMason DJ, Lopéz-Amorós R, Allman R, Stark JM, Lloyd D
JournalJ Appl Bacteriol
PubMed ID7537262
'Various dyes were assessed for their ability to discriminate between viable and non-viable bacteria. Two methods of killing were employed: by heat treatment or by gramicidin treatment. Staining was carried out in two ways; by staining directly in the medium or by washing cells prior to staining in buffer. Carbocyanine ... More
Characterization of Zn(2+) transport in Madin-Darby canine kidney cells.
AuthorsDucoudret O, Barbier O, Tauc M, Fuchs M, Poujeol P
JournalBiochim Biophys Acta
PubMed ID12659958
'The aim of this study was to characterize the mechanism implicated in Zn(2+) transport in MDCK cells. Trace elements such as Zn(2+), Cd(2+) or Cu(2+) induced MDCK cell depolarization at the micromolar level as demonstrated by bis-oxonol fluorescence and whole-cell patch experiments. This depolarization was inhibited by La(3+) and Gd(3+) ... More
Rapid measurement of toxicity using electrochromic dyes and frog embryos.
AuthorsStringer BK, Blankemeyer JT
JournalBull Environ Contam Toxicol
PubMed ID7691282
Flow cytometric detection of fluorescent redistributional dyes for measurement of cell transmembrane potential.
AuthorsTanner MK, Wellhausen SR
JournalMethods Mol Biol
PubMed ID9664484
P-glycoprotein multidrug resistance and cancer.
AuthorsBosch I, Croop J
JournalBiochim Biophys Acta
PubMed ID8876632
Cell membrane potential analysis.
AuthorsShapiro HM
JournalMethods Cell Biol
PubMed ID7532258
Intracellular ion activities and membrane transport in parietal cells measured with fluorescent dyes.
AuthorsNegulescu PA, Machen TE
JournalMethods Enzymol
PubMed ID2074799
The purpose of this chapter is to summarize the methods we have usedfor measuring intracellular pH with BCECF, intracellular calcium with fura-2 and intracellular sodium with SBFI in single, identified cells of gastricglands isolated from rabbits. ... More
Modulation of intracellular Na+ concentration by BmK AS, a scorpion toxin, in B104 cell line.
AuthorsTan ZY, Chen J, Feng XH, Susumu T, Ji YH
JournalNeuroreport
PubMed ID15106823
ABSL Effects of BmK AS, a toxin from scorpion Buthus mortensi Karsch and an activator of skeletal muscle RyRs, on the intracellular Na+ concentration have been investigated in the B104 neuroblastoma cell line by fluorescence digital imaging techniques. The intracellular Na+ concentration was elevated by 500 nM BmK AS significantly ... More
Insulin stimulation of glucose uptake and the transmembrane potential of muscle cells in culture.
AuthorsKlip A, Ramlal T, Walker D
JournalFEBS Lett
PubMed ID3527748
The membrane potential of L6 muscle cells was measured with the fluorescent dye bis-oxonol. Hyperpolarizations of up to 15 mV were caused by gramicidin (in N-methyl-D-glucamine+ medium), or by monensin or ionomycin. Depolarization was achieved with gramicidin (in Na+ medium), or with K+. Insulin did not change the resting membrane ... More
Spectroscopic studies of the interactions of the pyrethroid insecticide fenvalerate with gramicidin.
AuthorsGhosh JK, Sarkar SN, Sikdar SK
JournalBiochem Mol Biol Int
PubMed ID9623761
Fenvalerate is a pyrethroid insecticide which interacts with ionic channels. Using circular dichroism technique we have studied the interaction of fenvalerate with gramicidin, a model channel peptide which transports ions. In most organic solvents, gramicidin exists as a double helix except in trifluoroethanol where it exists as a channel forming ... More
Influence of lipid-soluble gating modifier toxins on sodium influx in neocortical neurons.
The electrical signals of neurons are fundamentally dependent on voltage-gated sodium channels (VGSCs), which are responsible for the rising phase of the action potential. An array of naturally occurring and synthetic neurotoxins have been identified that modify the gating properties of VGSCs. Using murine neocortical neurons in primary culture, we ... More
Sodium channel activation augments NMDA receptor function and promotes neurite outgrowth in immature cerebrocortical neurons.
A range of extrinsic signals, including afferent activity, affect neuronal growth and plasticity. Neuronal activity regulates intracellular Ca(2+), and activity-dependent calcium signaling has been shown to regulate dendritic growth and branching (Konur and Ghosh, 2005). NMDA receptor (NMDAR) stimulation of Ca(2+)/calmodulin-dependent protein kinase signaling cascades has, moreover, been demonstrated to ... More
Simultaneous measurement of [Na+]i and Ca2+ transients in an isolated myocyte: effects of strophanthidin.
AuthorsTerada H, Hayashi H, Satoh H, Katoh H, Yamazaki N
JournalBiochem Biophys Res Commun
PubMed ID8093022
We have developed a new method to measure [Na+]i and Ca2+ transients of a beating cardiac myocyte using a Na(+)-sensitive fluorescent probe, sodium-binding benzofuran isophthalate (SBFI) and a Ca(2+)-sensitive fluorescent probe, fluo-3. There was no interaction between two probes, and the artifact due to contraction could be eliminated in the ... More
Heterodimer formation and crystal nucleation of gramicidin D.
AuthorsBurkhart BM, Gassman RM, Langs DA, Pangborn WA, Duax WL
JournalBiophys J
PubMed ID9788907
The linear pentadecapeptide antibiotic gramicidin D is a heterogeneous mixture of six components. Precise refinements of three-dimensional structures of naturally occurring gramicidin D in crystals obtained from methanol, ethanol, and n-propanol demonstrate the unexpected presence of stable left-handed antiparallel double-helical heterodimers that vary with the crystallization solvent. The side chains ... More
13C solid-state NMR of gramicidin A in a lipid membrane.
AuthorsQuist PO
JournalBiophys J
PubMed ID9788943
The natural-abundance 13C NMR spectrum of gramicidin A in a lipid membrane was acquired under magic-angle spinning conditions. With fast sample spinning (15 kHz) at approximately 65 degrees C the peaks from several of the aliphatic, beta-, alpha-, aromatic, and carbonyl carbons in the peptide could be resolved. The resolution ... More
Evidence for a phorbol ester-insensitive phosphorylation step in capacitative calcium entry in rat thymic lymphocytes.
AuthorsMarriott I, Mason MJ
JournalJ Biol Chem
PubMed ID8900152
Experiments were undertaken to investigate the regulation of capacitative Ca2+ entry by phorbol ester-sensitive protein kinase C and serine/threonine protein phosphatase activity. The thapsigargin-activated Ca2+ entry pathway was probed in control cells and cells treated with phosphatase type 1/2A inhibitors, okadaic acid and calyculin A, or with the phorbol ester, ... More
Peroxyl radicals promoted changes in water permeability through gramicidin channels in DPPC and lecithin-PC vesicles.
AuthorsSoto MA, Sotomayor CP, Lissi EA
JournalChem Phys Lipids
PubMed ID12637166
Gramicidin incorporation to DPPC or lecithin-PC large unilamellar vesicles (LUVs) leads to pore formation that, under hyper-osmotic conditions, produces a noticeable increase in the rate of trans-membrane water flow. This pore formation is more efficient in the more fluid lecithin-PC LUVs. Exposure of these vesicles to peroxyl radicals generated in ... More
Intracellular ionic variations in the apoptotic death of L cells by inhibitors of cell cycle progression.
AuthorsBarbiero G, Duranti F, Bonelli G, Amenta JS, Baccino FM
JournalExp Cell Res
PubMed ID7698242
Treatment with VP-16 (1-50 microM) or excess thymidine (5 mM) caused a block of L cells at different steps in their progression through the replicative cycle. The arrest was followed by an asynchronous process of cell death that conformed to criteria for apoptosis. Careful monitoring of this process in the ... More
The fluorescent cationic dye rhodamine 6G as a probe for membrane potential in bovine aortic endothelial cells.
AuthorsMandalà M, Serck-Hanssen G, Martino G, Helle KB
JournalAnal Biochem
PubMed ID10527490
The membrane potential of cultured bovine aortic endothelial cells was assessed by a fluorescent probe as an alternative to direct methods. We used the fluorescent cationic dye rhodamine 6G, a lipophilic probe with high permeability in cell membranes. A linear relationship was obtained between fluorescence intensity (F.I.) and membrane potential ... More
Toxin pharmacology of the ATP-induced hyperpolarization in Madin-Darby canine kidney cells.
AuthorsTauc M, Gastineau M, Poujeol P
JournalBiochim Biophys Acta
PubMed ID1373656
The effects of Leiurus quinquestriatus hebraeus (LQH) venom, mamba venom, Buthus tamulus (BT) venom, purified apamin and synthetic charybdotoxin on the membrane hyperpolarization induced by extracellular ATP were examined in Madin-Darby canine kidney cells. For this we used a membrane potential probe (bisoxonol) to determine the potential variations. The relation ... More
Caspase-8-mediated BID cleavage and release of mitochondrial cytochrome c during Nomega-hydroxy-L-arginine-induced apoptosis in MDA-MB-468 cells. Antagonistic effects of L-ornithine.
AuthorsSingh R, Pervin S, Chaudhuri G
JournalJ Biol Chem
PubMed ID12145284
We have previously reported that N(omega)-hydroxy-l-arginine (NOHA), a stable intermediate product formed during the conversion of l-arginine to nitric oxide, induced apoptosis in MDA-MB-468 cells, and this action was antagonized in the presence of l-ornithine. We also reported that apoptosis induced by NOHA in this cell line could not be ... More
Fluorescence lifetime microscopy of the sodium indicator sodium-binding benzofuran isophthalate in HeLa cells.
AuthorsDespa S, Steels P, Ameloot M
JournalAnal Biochem
PubMed ID10790305
The behavior of the sodium indicator sodium-binding benzofuran isophthalate (SBFI) is investigated in HeLa cells by time-resolved fluorescence microscopy. The fluorescence relaxation of SBFI in HeLa cells can be described by a triexponential for intracellular sodium concentration ([Na(+)](i)) between 0 and 90 mM. Changes in [Na(+)](i) affect neither the fluorescence ... More
Fluorescence lifetime microscopy of the Na+ indicator Sodium Green in HeLa cells.
AuthorsDespa S, Vecer J, Steels P, Ameloot M
JournalAnal Biochem
PubMed ID10870831
This study investigates the usefulness of lifetime measurements of Sodium Green for evaluating intracellular Na+ concentration ([Na+]i) in HeLa cells. Frequency-domain lifetime measurements are performed in HeLa cells and in different buffer solutions (with and without K+ and bovine serum albumin). In all cases, the fluorescence decays of Sodium Green ... More
Membrane depolarization was required to induce DNA synthesis in murine macrophage cell line PU5-1.8.
AuthorsKong SK, Suen YK, Choy YM, Fung KP, Lee CY
JournalImmunopharmacol Immunotoxicol
PubMed ID1940052
The role of membrane potential (Em) on the initiation of DNA synthesis in murine macrophage cell line PU5-1.8 was investigated with fluorescent probes bis-oxonol and diS-C3-(5). Incubation of PU5-1.8 cells in high K(+)-HEPES buffer or with gramicidin at 37 degrees C for 1h that depolarized the membrane induced [3H]-thymidine incorporation ... More
Na/K pump current and [Na](i) in rabbit ventricular myocytes: local [Na](i) depletion and Na buffering.
AuthorsDespa S, Bers DM
JournalBiophys J
PubMed ID12770918
Na/K pump current (I(pump)) and intracellular Na concentration ([Na](i)) were measured simultaneously in voltage-clamped rabbit ventricular myocytes, under conditions where [Na](i) is controlled mainly by membrane transport. Upon abrupt pump reactivation (after 10-12 min blockade), I(pump) decays in two phases. Initially, I(pump) declines with little [Na](i) change, whereas the second ... More
New fluorescent octadecapentaenoic acids as probes of lipid membranes and protein-lipid interactions.
AuthorsMateo CR, Souto AA, Amat-Guerri F, Acuña AU
JournalBiophys J
PubMed ID8889194
The chemical and spectroscopic properties of the new fluorescent acids all(E)-8, 10, 12, 14, 16-octadecapentaenoic acid (t-COPA) and its (8Z)-isomer (c-COPA) have been characterized in solvents of different polarity, synthetic lipid bilayers, and lipid/protein systems. These compounds are reasonably photostable in solution, present an intense UV absorption band (epsilon(350 nm) ... More
Interaction of multidrug-resistant Chinese hamster ovary cells with the peptide ionophore gramicidin D.
AuthorsLoe DW, Sharom FJ
JournalBiochim Biophys Acta
PubMed ID7509193
A major form of multidrug resistance results from the overexpression of P-glycoprotein, a 170 kDa membrane protein. Multidrug resistant (MDR) Chinese hamster ovary (CHO) cells and mdrl transfectants displayed cross-resistance to the channel-forming peptide ionophore gramicidin D, which was reversed by various chemosensitizers, thus directly implicating P-glycoprotein as the mediator ... More
Regulation of [Na+]i and [Ca2+]i in guinea pig myocytes: dual loading of fluorescent indicators SBFI and fluo 3.
AuthorsSatoh H, Hayashi H, Noda N, Terada H, Kobayashi A, Hirano M, Yamashita Y, Yamazaki N
JournalAm J Physiol
PubMed ID8141358
To investigate the mechanisms regulating intracellular Na+ and Ca2+ concentrations ([Na+]i and [Ca2+]i, respectively), we monitored both ion concentrations simultaneously using fluorescent probes, Na(+)-binding benzofuran isophthalate (SBFI) and fluo 3, in unstimulated guinea pig ventricular myocytes. After the addition of 500 microM strophanthidin, [Na+]i increased gradually from 6.6 +/- 0.6 ... More
Interaction of the P-glycoprotein multidrug transporter with peptides and ionophores.
AuthorsSharom FJ, DiDiodato G, Yu X, Ashbourne KJ
JournalJ Biol Chem
PubMed ID7730340
P-glycoprotein functions as an ATP-driven active efflux pump for many cytotoxic drugs. We now show that hydrophobic peptides and ionophores also interact with the multidrug transporter. Multidrug-resistant cells are cross-resistant to several hydrophobic peptides and ionophores, but not to some other membrane-active species. Linear peptides, cyclic peptides, and ionophores stimulated ... More
Dimerization constant and single-channel conductance of gramicidin in thylakoid membranes.
AuthorsSchönknecht G, Althoff G, Junge W
JournalJ Membr Biol
PubMed ID1378501
The effect of the pore-forming antibiotic gramicidin on pure lipid membranes is well characterized. We studied its action in protein-rich thylakoid membranes that contain less than 25% (wt/wt) acyl lipids. A transmembrane voltage was induced by flashing light, and its decay was measured and interpreted to yield the distribution of ... More
Determination of the intracellular dissociation constant, K(D), of the fluo-3. Ca(2+) complex in mouse sperm for use in estimating intracellular Ca(2+) concentrations.
AuthorsRockwell PL, Storey BT
JournalMol Reprod Dev
PubMed ID10542383
In order to calculate the actual, rather than the relative, intracellular Ca(2+) concentration (Ca(2+))(i) in mammalian sperm cells, using fluorescent probes whose fluorescence emission differs between the probe. Ca(2+) complex and free probe, the value of the dissociation constant for the probe. Ca(2+) complex, K(D), is required. Interaction of the ... More
Staining of mitochondrial membranes with 10-nonyl acridine orange, MitoFluor Green, and MitoTracker Green is affected by mitochondrial membrane potential altering drugs.
AuthorsKeij JF, Bell-Prince C, Steinkamp JA
JournalCytometry
PubMed ID10685077
BACKGROUND: We set out to develop an assay for the simultaneous analysis of mitochondrial membrane potential and mass using the probes 10-nonyl acridine orange (NAO), MitoFluor Green (MFG), and MitoTracker Green (MTG) in HL60 cells. However, in experiments in which NAO and MFG were combined with orange emitting mitochondrial membrane ... More
Mechanism of interaction of different classes of cationic antimicrobial peptides with planar bilayers and with the cytoplasmic membrane of Escherichia coli.
AuthorsWu M, Maier E, Benz R, Hancock RE
JournalBiochemistry
PubMed ID10353835
Antimicrobial cationic peptides are prevalent throughout nature as part of the intrinsic defenses of most organisms, and have been proposed as a blueprint for the design of novel antimicrobial agents. They are known to interact with membranes, and it has been frequently proposed that this represents their antibacterial target. To ... More
Kinetics of onset of mouse sperm acrosome reaction induced by solubilized zona pellucida: fluorimetric determination of loss of pH gradient between acrosomal lumen and medium monitored by dapoxyl (2-aminoethyl) sulfonamide and of intracellular Ca(2+) changes monitored by fluo-3.
AuthorsRockwell PL, Storey BT
JournalMol Reprod Dev
PubMed ID10657053
The onset of the zona pellucida-induced acrosome reaction in mouse sperm is marked by loss of the pH gradient existing in acrosome-intact sperm between the acidic acrosomal lumen and the suspending medium, due to pore formation between outer acrosomal and plasma membranes. In earlier work, it was shown that this ... More
Modulation of concentration fluctuations in phase-separated lipid membranes by polypeptide insertion.
AuthorsFahsel S, Pospiech EM, Zein M, Hazlet TL, Gratton E, Winter R
JournalBiophys J
PubMed ID12080124
The lateral membrane organization and phase behavior of the binary lipid mixture DMPC (1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine) - DSPC (1,2-distearoyl-sn-glycero-3-phosphatidylcholine) without and with incorporated gramicidin D (GD) as a model biomembrane polypeptide was studied by small-angle neutron scattering, Fourier-transform infrared spectroscopy, and by two-photon excitation fluorescence microscopy on giant unilamellar vesicles. The small-angle ... More