Electron spin resonance study of light-induced conformational changes in nitroxide labelled bovine rhodopsin.
Bovine rhodopsin was isolated in the unbleached form as a retinal disc membrane suspension and spin-labelled with 4-maleimido-2,2,6,6-tetramethylpiperidine-N-oxyl. Both conventional and saturation transfer electron spin resonance methods were used to investigate the sensitivity of the spin-label to conformational changes of rhodopsin induced by both transient and long-term exposure to light. The results indicate that the ESR methods do display sensitivity to such changes. An exponential decay curve with a time constant of 10 s was obtained by following the height of a single peak in the saturation transfer electron spin resonance spectrum in response to a single light flash.
Rowntree
J I
JI
Department of Biochemistry, University of Oxford, England.
Watts
A
A
D000818:Animals; D002417:Cattle; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D008027:Light; D011487:Protein Conformation; D012168:Retinal Pigments; D012243:Rhodopsin; D013113:Spin Labels
D003497:Cyclic N-Oxides; D012168:Retinal Pigments; D013113:Spin Labels; D012243:Rhodopsin; C003959:TEMPO