title: Effect of temperature on the kinetics of electron transfer from the tetraheme cytochrome to the primary donor in Rhodopseudomonas viridis.
abstract: The kinetics of electron transfer from the third highest potential heme (c-552, Em = +20 mV) to the primary donor (P-960) have been measured by flash absorption spectroscopy in isolated reaction centers of Rhodopseudomonas viridis between 300 K and 7 K. The data are analyzed on the basis of three exponential components with a very fast phase (t1/2 = 120 ns) dominating at high temperature and a very slow one (t1/2 = 1.2 ms) at low temperature. This multiphasic behavior is interpreted in terms of the existence of three states with a temperature-dependent population and a very limited effect of the temperature on the kinetics for each state.
authors.affiliation: Département de Biologie Cellulaire et Moléculaire, C.E. Saclay, Gif-sur-Yvette, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Ortega
authors.forename: P
authors.initials: P
authors.lastname: Mathis
mesh_terms: D003080:Cold Temperature; D003574:Cytochrome c Group / Q000378:metabolism*; D004579:Electron Transport; D007700:Kinetics; D010788:Photosynthesis / Q000502:physiology; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D012241:Rhodopseudomonas / Q000378:metabolism*; D013053:Spectrophotometry
chemical_list: D003574:Cytochrome c Group; D045322:Photosynthetic Reaction Center Complex Proteins; C083951:cytochrome c553; C022302:cytochrome C-552