期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1981
卷号:78
期号:1
页码:252-255
DOI:10.1073/pnas.78.1.252
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The photolysis-induced changes in the protein fluorescence intensity (at 320 nm) during the proton-pumping cycle of bacteriorhodopsin were examined by a delayed two-pulse technique in the time range 1 microsecond-20 msec at room temperature. No detectable change in the protein fluorescence intensity was observed on the earliest time scale within the lifetime of the intermediate K590, when retinal apparently undergoes the largest structural changes. The time dependence of the relative changes in fluorescence intensity did, however, display a close correlation with the population of the L550 and M412 intermediates. From a computer numerical fit of the data, with available published kinetic parameters, the protein fluorescence quantum yields of the K590, L550, and M412 intermediates are found to be 1.0, 0.92, and 0.80 of that for native bR570, respectively. The probable mechanisms of the observed fluorescence quenching during the photochemical cycle are qualitatively discussed.