The natural product capsaicin inhibits photosynthetic electron transport at the reducing side of photosystem II and purple bacterial reaction center: structural details of capsaicin binding.
Capsaicin, a natural quinone analog, was found to block electron transport, in both plant photosystem II (PSII) and bacterial reaction center (RC) from Rhodobacter sphaeroides, at the QB site. The mode of action of capsaicin was investigated by O2 evolution measurements and fluoresence induction studies in the case of PSII, and flash-induced absorbance spectroscopy in the case of the bacterial RC. Structural details of capsaicin binding to the bacterial RC complex were determined by X-ray crystallographic analysis.
Spyridaki
A
A
Department of Chemistry, University of Crete, Heraklion, Greece.
Fritzsch
G
G
Kouimtzoglou
E
E
Baciou
L
L
Ghanotakis
D
D
D001665:Binding Sites; D002211:Capsaicin / Q000494:pharmacology*; D004237:Diuron; D004579:Electron Transport / Q000187:drug effects; D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000187:drug effects*; D045332:Photosystem II Protein Complex; D012242:Rhodobacter sphaeroides; D018724:Spinacia oleracea; D014451:Ubiquinone / Q000737:chemistry; D014961:X-Ray Diffraction
D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D014451:Ubiquinone; D004237:Diuron; D002211:Capsaicin