[Kinetic model of the effect of dehydration on electron transfer from membrane-bound cytochrome c to the photosynthetic reaction center].

Abstract

Amplitude characteristics and kinetics of laser-induced oxidation of high-potential cytochrome CH by a photosynthetic reaction center (RC) were investigated in Ectothiorhodospira shaposhnikovii chromatophore preparations of various humidity. It is shown that the diminuition of the amount of oxidized cytochrome and the decrease of the rate of the reaction on lowering the preparation humidity can be explained in terms of the concept of conformation-controlled electron transfer within the CH-RC complex. A model is suggested which predicts that the reversible transition of the complex from one conformational state which allows electron transfer ("contact" state) to the other in which the transfer is impossible ("non-contact" state) is the result of drying (or low temperature) induced changes in the electron tunnelling path in the region of "contact" of the cytochrome CH and RC protein globules.

• Authors: E G Petrov, S K Chamorovskiĭ, A A Kononenko, A B Rubin
• Journal: Molekuliarnaia biologiia (Mol Biol (Mosk)) 1985 May-Jun Vol. 19 Issue 3 Pg. 643-53 ISSN: 0026-8984 [Print] Russia (Federation)
• Vernacular Title: Kineticheskaia model' vliianiia degidratatsii na perenos élektrona ot sviazannogo s membranoĭ tsitokhroma c na fotosinteticheskiĭ reaktsionnyĭ tsentr.
• PMID: 2993853 (Publication Type: English Abstract, Journal Article)

Chemical References

• Bacterial Proteins
• Cytochrome c Group
• Photosynthetic Reaction Center Complex Proteins

Topics

• Bacteria (enzymology, metabolism)
• Bacterial Chromatophores (metabolism)
• Bacterial Proteins (metabolism)
• Cell Membrane (enzymology)
• Cytochrome c Group (metabolism)
• Desiccation
• Electron Transport
• Kinetics
• Models, Biological
• Photosynthesis
• Photosynthetic Reaction Center Complex Proteins