title: Ultrafast haem-haem electron transfer in cytochrome c oxidase.
abstract: Electron transfer between the redox centres is essential for the function of the haem-copper oxidases. To date, the fastest rate of electron transfer between the haem groups has been determined to be ca. 3 x 10(5) s(-1). Here, we show by optical spectroscopy that about one half of this electron transfer actually occurs at least three orders of magnitude faster, after photolysis of carbon monoxide from the half-reduced bovine heart enzyme. We ascribe this to the true haem-haem electron tunnelling rate between the haem groups.
authors.affiliation: Helsinki Bioenergetics Group, Institute of Biotechnology and Biocentrum Helsinki, Biocenter 2, Room 2011, P.O. Box 56, University of Helsinki, FI-00014 Helsinki, Finland. marten.wikstrom@helsinki.fi
authors.forename: M I
authors.initials: MI
authors.lastname: Verkhovsky
authors.forename: A
authors.initials: A
authors.lastname: Jasaitis
authors.forename: M
authors.initials: M
authors.lastname: Wikström
mesh_terms: D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000737:chemistry*; D006418:Heme / Q000737:chemistry*; D010084:Oxidation-Reduction; D010782:Photolysis; D013057:Spectrum Analysis / Q000379:methods; D013997:Time Factors
chemical_list: D006418:Heme; D003576:Electron Transport Complex IV