Effect of single-site charge-reversal mutations on the catalytic properties of yeast cytochrome c peroxidase: mutations near the high-affinity cytochrome c binding site.

ABSTRACT: Fifteen single-site charge-reversal mutations of yeast cytochrome c peroxidase (CcP) have been constructed to determine the effect of localized charge on the catalytic properties of the enzyme. The mutations are located on the front face of CcP, near the cytochrome c binding site identified in the crystallographic structure of the yeast cytochrome c-CcP complex [Pelletier, H., and Kraut, J. (1992) Science 258, 1748-1755]. The mutants are characterized by absorption spectroscopy and hydrogen peroxide reactivity at both pH 6.0 and 7.5 and by steady-state kinetic studies using recombinant yeast iso-1-ferrocytochrome c(C102T) as a substrate at pH 7.5. Some of the charge-reversal mutations cause detectable changes in the absorption spectrum, especially at pH 7.5, reflecting changes in the equil

SUBMITTER: Pearl NM 

PROVIDER: S-EPMC2547122 | biostudies-literature | 2007 Jul

REPOSITORIES: biostudies-literature