ISSN:
1432-1327
Keywords:
Key words Cytochrome c3
;
Hydrogenase
;
Energy transduction
;
Electron transfer mechanism
;
Redox-Bohr
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract Using potentiometric titrations, two protons were found to participate in the redox-Bohr effect observed for cytochrome c 3 from Desulfovibrio vulgaris (Hildenborough). Within the framework of the thermodynamic model previously presented, this finding supports the occurrence of a concerted proton-assisted 2e– step, ideally suited for the coupling role of cytochrome c 3 to hydrogenase. Furthermore, at physiological pH, it is shown that when sulfate-reducing bacteria use H2 as energy source, cytochrome c 3 can be used as a charge separation device, achieving energy transduction by energising protons which can be left in the acidic periplasmic side and transferring deenergised electrons to sulfate respiration. This mechanism for energy transduction, using a full thermodynamic data set, is compared to that put forward to explain the proton-pumping function of cytochrome c oxidase.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s007750050020
