Photoaccumulation of the PsaB phyllosemiquinone in photosystem I of Chlamydomonas reinhardtii
| Autor: | Michael C.W. Evans, Stephen E. J. Rigby, Peter Heathcote, Saul Purton, Irine P. Muhiuddin |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Photosystem I
Proton Photosynthetic Reaction Center Complex Proteins Biophysics Chlamydomonas reinhardtii Photochemistry Biochemistry law.invention Electron Transport Electron transfer law PsaB Animals Electron paramagnetic resonance Hyperfine structure Electron nuclear double resonance P700 biology Photosystem I Protein Complex Chemistry Sulfates Electron Spin Resonance Spectroscopy Temperature Membrane Proteins Phyllosemiquinone Cell Biology Vitamin K 1 ENDOR Hydrogen-Ion Concentration biology.organism_classification Magnetic resonance Photoaccumulation Anisotropy |
| Zdroj: | Biochimica et biophysica acta. 1556(1) |
| ISSN: | 0006-3002 |
| Popis: | Photoaccumulation of membrane preparations of Chlamydomonas reinhardtii at pH 8 and 220 K reduces the primary and secondary electron acceptors in the Photosystem I (PSI) reaction centre, and produces a maximum of two spins per P700 + . Proton electron nuclear double resonance (ENDOR) spectra demonstrate that the phyllosemiquinone produced is that attributed to the PsaA branch of electron transfer. Photoaccumulation at pH 10 and 220 K produces a maximum of four spins per P700 + , and proton ENDOR spectra indicate that a second phyllosemiquinone is being photoaccumulated, with markedly different proton hyperfine couplings (hfcs). This phyllosemiquinone is unaffected by mutation of PsaAW693, confirming that it does not arise from the PsaA branch of electron transfer, and we therefore attribute it to the PsaB phyllosemiquinone. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|