Electron transfer from cytochrome c(2) to the reaction center: a transition state model for ionic strength effects due to neutral mutations.

ABSTRACT: Interprotein electron transfer plays an important role in biological energy conversion. In this work, the electron transfer reaction between cytochrome c(2) (cyt) and the reaction center (RC) was studied to determine the mechanisms coupling association and electron transfer. Previous studies have shown that mutation of hydrophobic residues in the reaction interface, particularly Tyr L162, changes the binding affinity and rates of electron transfer at low ionic strengths. In this study, the effect of ionic strength on the second-order electron transfer rate constant, k(2), between cyt c(2) and native or mutant RCs was examined. Mutations of hydrophobic and hydrogen bonding residues caused k(2) to decrease more rapidly with an increase in ionic strength. This change is explained with a trans

SUBMITTER: Abresch EC 

PROVIDER: S-EPMC2789999 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature