Conformational stability of CopC and roles of residues Tyr79 and Trp83.

ABSTRACT: CopC is a periplasmic copper Chaperone protein that has a β-barrel fold and two metal-binding sites distinct for Cu(II) and Cu(I). In the article, four mutants (Y79F, Y79W, Y79WW83L, Y79WW83F) were obtained by site-directed mutagenesis. The far-UV CD spectra of the proteins were similar, suggesting that mutations did not bring any significant changes in secondary structures. Meanwhile the effects of mutations on the protein's function were manifested by Cu(II) binding. Fluorescence lifetime measurement and quenching of tryptophan fluorescence by acrylamide and KI showed that the microenvironment around Trp83 was more hydrophobic than that around Tyr79 in apoCopC. Unfolding experiments induced by guanidinium chloride (GdnHCl), urea provided the conformational stability of each protein. The

SUBMITTER: Song Z 

PROVIDER: S-EPMC3831667 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature