Electrogenic steps during electron transfer via the cytochrome bc 1 complex of Rhodobacter sphaeroides chromatophores

[摘要]

The results of the flash-induced electrometrical investigation on the functioning of the photosynthetic bacterial cytochrome bc ₁ complex are discussed. The data suggest possible arrangement of redox centers in the bc ₁ complex and propose that the total electrogenesis within the bc ₁ complex includes: (i) electron transfer between the low- and the high-potential cytochrome b hemes, (ii) proton binding by doubly reduced Q²⁻ at ubiquinone-reducing center ‘C’, and (iii) proton release on oxidation of QH₂ at ubiquinol-oxidizing center ‘Z’.

[学科分类] 生物化学/生物物理

[关键词] Bacterial photosynthesis;bc 1 complex;Electrogenic reaction;Rhodobacter sphaeroides;RC;reaction center complex;ΔΨ;electric potential difference;QC and QZ;the quinone-reducing and quinol-oxidizing sites;respectively;b 1 and b h;the low- and the high-potential cytochrome b hemes;respectively;P+QA −;primary dipole in bacterial RC;QB;the secondary quinone acceptor in RC