Du J J, el-Sayed M A, Stern L J, Mogi T, Khorana H G
Department of Chemistry and Biochemistry, University of California, Los Angeles 90024.
FEBS Lett. 1990 Mar 26;262(2):155-8. doi: 10.1016/0014-5793(90)80178-l.
Bacteriorhodopsin (bR) in the native purple membrane, in wild type expressed in E. coli and reconstituted in lipid vesicles, and its constituted mutants with substitutions of Tyr-185 by Phe all are found to have different visible retinal CD spectra. The results strongly suggest that the environment of the retinal in bR determines the sign and heterogeneity of its visible retinal CD spectrum. This supports the recent proposal that the observed biphasic CD spectrum of bR is due to the superposition of the CD spectra having opposite signs of more than one type of bR rather than due to exciton coupling.
天然紫色膜中的细菌视紫红质（bR）、在大肠杆菌中表达并在脂质囊泡中重构的野生型bR及其将Tyr-185替换为Phe的组成型突变体，均被发现具有不同的可见视网膜圆二色光谱。结果有力地表明，bR中视网膜的环境决定了其可见视网膜圆二色光谱的符号和异质性。这支持了最近的提议，即观察到的bR的双相圆二色光谱是由于不止一种类型的bR的具有相反符号的圆二色光谱的叠加，而不是由于激子耦合。
