TY - JOUR
T1 - Redox-Bohr effect in electron/proton energy transduction
T2 - Cytochrome c3 coupled to hydrogenase works as a 'proton thruster' in Desulfovibrio vulgaris
AU - Louro, Ricardo O.
AU - Catarino, Teresa
AU - LeGall, Jean
AU - Xavier, António V.
PY - 1997/8/1
Y1 - 1997/8/1
N2 - A central step in the metabolism of Desulfovibrio spp. is the oxidation of molecular hydrogen catalyzed by a periplasmic hydrogenase. However, this enzymatic activity is quite low at physiological pH. The hypothesis that, in the presence of the tetrahaem cytochrome c3, hydrogenase can maintain full activity at physiological pH through the concerted capture of the resulting electrons and protons by the cytochrome was tested for the case of Desulfovibrio vulgaris (Hildenborough). The crucial step involves an electron-to-proton energy transduction, and is achieved through a net-work of cooperativities between redox and ionizable centers within the cytochrome (redox-Bohr effect). This mechanism, which requires a relocation of the proposed proton channel in the hydrogenase structure, is similar to that proposed for the transmembrane proton pumps, and is the first example which shows evidence of functional energy transduction in the absence of a membrane confinement.
AB - A central step in the metabolism of Desulfovibrio spp. is the oxidation of molecular hydrogen catalyzed by a periplasmic hydrogenase. However, this enzymatic activity is quite low at physiological pH. The hypothesis that, in the presence of the tetrahaem cytochrome c3, hydrogenase can maintain full activity at physiological pH through the concerted capture of the resulting electrons and protons by the cytochrome was tested for the case of Desulfovibrio vulgaris (Hildenborough). The crucial step involves an electron-to-proton energy transduction, and is achieved through a net-work of cooperativities between redox and ionizable centers within the cytochrome (redox-Bohr effect). This mechanism, which requires a relocation of the proposed proton channel in the hydrogenase structure, is similar to that proposed for the transmembrane proton pumps, and is the first example which shows evidence of functional energy transduction in the absence of a membrane confinement.
KW - Cytochrome c
KW - Electron transfer
KW - Energy transduction
KW - Proton transfer
KW - Redox-Bohr
UR - http://www.scopus.com/inward/record.url?scp=0030876306&partnerID=8YFLogxK
U2 - 10.1007/s007750050160
DO - 10.1007/s007750050160
M3 - Article
AN - SCOPUS:0030876306
SN - 0949-8257
VL - 2
SP - 488
EP - 491
JO - JBIC Journal of Biological Inorganic Chemistry
JF - JBIC Journal of Biological Inorganic Chemistry
IS - 4
ER -