Magnetic interactions sense changes in distance between heme b(L) and the iron-sulfur cluster in cytochrome bc(1).

ABSTRACT: During the operation of cytochrome bc(1), a key enzyme of biological energy conversion, the iron-sulfur head domain of one of the subunits of the catalytic core undergoes a large-scale movement from the catalytic quinone oxidation Q(o) site to cytochrome c(1). This changes a distance between the two iron-two sulfur (FeS) cluster and other cofactors of the redox chains. Although the role and the mechanism of this movement have been intensely studied, they both remain poorly understood, partly because the movement itself is not easily traceable experimentally. Here, we take advantage of magnetic interactions between the reduced FeS cluster and oxidized heme b(L) to use dipolar enhancement of phase relaxation of the FeS cluster as a spectroscopic parameter which with a unique clarity and spec

SUBMITTER: Sarewicz M 

PROVIDER: S-EPMC2697599 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature