Godik V, Timpmann K, Freiberg A, Moskalenko A A
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation.
FEBS Lett. 1993 Jul 19;327(1):68-70. doi: 10.1016/0014-5793(93)81041-w.
The picosecond dynamics of excitations in the isolated B800-850 light-harvesting complex of the purple sulfur bacterium Chromatium minutissimum has been studied using picosecond fluorescence spectrochronography. A short-lived component of about 20 ps lifetime has been found at 77K at the short wavelength part of the B850 fluorescence spectrum similar to that previously described for the core antenna bacteriochlorophyll band B880 of Rhodospirillum rubrum. Evidence has been presented indicating that this component is likely to reflect excitation energy relaxation step(s) involving both photoexcited bacteriochlorophyll and the protein environment. A new kinetic scheme of excitation transfer from the peripheral antenna to the photoreceptor units in purple bacteria is suggested which takes into account these findings.
利用皮秒荧光光谱计时法研究了极小色硫细菌中分离出的B800 - 850光捕获复合体中激发态的皮秒动力学。在77K下，B850荧光光谱的短波长部分发现了一个寿命约为20皮秒的短寿命组分，这与之前描述的红螺菌核心天线细菌叶绿素B880带相似。已有证据表明，该组分可能反映了涉及光激发细菌叶绿素和蛋白质环境的激发能弛豫步骤。考虑到这些发现，提出了一种紫色细菌中从外周天线到光感受器单元的激发转移新动力学方案。
