title: Mechanism and energetics of proton translocation by the respiratory heme-copper oxidases.
abstract: Recent time-resolved optical and electrometric experiments have provided a sequence of events for the proton-translocating mechanism of cytochrome c oxidase. These data also set limits for the mechanistic, kinetic, and thermodynamic parameters of the proton pump, which are analysed here in some detail. The analysis yields limit values for the pK of the "pump site", its modulation during the proton-pumping process, and suggests its identity in the structure. Special emphasis is made on side-reactions that may short-circuit the pump, and the means by which these may be avoided. We will also discuss the most prominent proton pumping mechanisms proposed to date in relation to these data.
authors: Helsinki Bioenergetics Group, Structural Biology and Biophysics Programme, Institute of Biotechnology, University of Helsinki, PB 65 (Viikinkaari 1), FI-00014 University of Helsinki, Finland. marten.wikstrom@helsinki.fi
authors: Mårten
authors: M
authors: Wikström
authors: Michael I
authors: MI
authors: Verkhovsky
mesh_terms: D000818:Animals; D001692:Biological Transport; D006418:Heme / Q000737:chemistry* / Q000378:metabolism*; D008954:Models, Biological; D010088:Oxidoreductases / Q000378:metabolism*; D011522:Protons; D013816:Thermodynamics
chemical_list: D011522:Protons; D006418:Heme; D010088:Oxidoreductases; C024748:copper oxidase