Biomimetic nanostructures: creating a high-affinity zinc-binding site in a folded nonbiological polymer.
AuthorsLee BC, Chu TK, Dill KA, Zuckermann RN,
JournalJ Am Chem Soc
PubMed ID18597438
'One of the long-term goals in developing advanced biomaterials is to generate protein-like nanostructures and functions from a completely nonnatural polymer. Toward that end, we introduced a high-affinity zinc-binding function into a peptoid (N-substituted glycine polymer) two-helix bundle. Borrowing from well-understood zinc-binding motifs in proteins, thiol and imidazole moieties were ... More
Determination of thermodynamic parameters of cadmium(II) association to glutathione using the fluorescent reagent FluoZin-1.
AuthorsOgawa S, Yoshimura E,
JournalAnal Biochem
PubMed ID20347670
'A method was developed to determine the conditional association constants of cadmium(II) [Cd(II)] complexes based on the reagent FluoZin-1, which forms a fluorescent complex with Cd(II). A solution containing Cd(II) and FluoZin-1 was titrated with glutathione while determining fluorescence intensity of FluoZin-1 to estimate levels of free Cd(II). The results ... More
Zn2+ binding to human calbindin D(28k) and the role of histidine residues.
We have studied the binding of Zn2+ to the hexa EF-hand protein, calbindin D(28k)-a strong Ca2+-binder involved in apoptosis regulation-which is highly expressed in brain tissue. By use of radioblots, isothermal titration calorimetry, and competition with a fluorescent Zn2+ chelator, we find that calbindin D(28k) binds Zn2+ to three rather ... More
A reevaluation of neuronal zinc measurements: artifacts associated with high intracellular dye concentration.
AuthorsDineley KE, Malaiyandi LM, Reynolds IJ
JournalMol Pharmacol
PubMed ID12181438
The emergence of zinc as a potent neurotoxin has prompted the development of techniques suitable for the measurement of intracellular free zinc ([Zn(2+)](i)) in cultured cells. Accordingly, a new family of Zn(2+)-sensitive fluorophores has become available. Using ionophore-induced elevations of [Zn(2+)](i) in cultured neurons, we measured [Zn(2+)](i)-induced changes in the ... More
Kinetic study of the antiport mechanism of an Escherichia coli zinc transporter, ZitB.
AuthorsChao Y, Fu D
JournalJ Biol Chem
PubMed ID14715669
ZitB is a member of the cation diffusion facilitator (CDF) family that mediates efflux of zinc across the plasma membrane of Escherichia coli. We describe the first kinetic study of the purified and reconstituted ZitB by stopped-flow measurements of transmembrane fluxes of metal ions using a metal-sensitive fluorescent indicator encapsulated ... More
Selective metal binding to a membrane-embedded aspartate in the Escherichia coli metal transporter YiiP (FieF).
AuthorsWei Y, Fu D
JournalJ Biol Chem
PubMed ID16049012
The cation diffusion facilitators (CDF) are a ubiquitous family of metal transporters that play important roles in homeostasis of a wide range of divalent metal cations. Molecular identities of substrate-binding sites and their metal selectivity in the CDF family are thus far unknown. By using isothermal titration calorimetry and stopped-flow ... More
Cd(2+)-induced cytochrome c release in apoptotic proximal tubule cells: role of mitochondrial permeability transition pore and Ca(2+) uniporter.
AuthorsLee WK, Bork U, Gholamrezaei F, Thévenod F
JournalAm J Physiol Renal Physiol
PubMed ID15339793
Cd(2+) induces apoptosis of kidney proximal tubule (PT) cells. Mitochondria play a pivotal role in toxic compound-induced apoptosis by releasing cytochrome c. Our objective was to investigate the mechanisms underlying Cd(2+)-induced cytochrome c release from mitochondria in rat PT cells. Using Hoechst 33342 or MTT assay, 10 muM Cd(2+) induced ... More