Xia A D, Zhu J C, Jiang L J, Li D L, Zhang X Y
Institute of Photographic Chemistry, Academia Sinica, Beijing P. R. China.
Biochem Biophys Res Commun. 1991 Aug 30;179(1):558-64. doi: 10.1016/0006-291x(91)91407-4.
The relaxation processes of C-phycocyanin at different aggregates have been investigated by pump-probe techniques. The lifetimes of ground state recovery measured at various wavelengths are analyzed by computer fitting of the kinetic data to a sum of three and four exponentials for monomers and trimers according to the nonlinear least-square principle, respectively. The shortest lifetime (about 56ps) is due to beta s----beta f transfer in one monomer, that decreases to 31ps in trimer due to the opening of new transfer channels. The second fastest component (about 151ps) in monomer is attributed tentatively to distribution of excitation energy between alpha and beta f chromophores, that decreases to about 117ps in trimer caused by redistribution of excitation energy between them. The two long-lived components (about 690ps and 1385ps for monomer, 620ps and 1320ps for trimer) from some kinds of heterogeneity in some chromophores, such as alpha and beta 1 chromophores which are emitting, show an equal amplitude ratio of 1:2 in both monomer and trimer.
采用泵浦-探测技术研究了不同聚集体状态下C-藻蓝蛋白的弛豫过程。根据非线性最小二乘法原理，分别将单体和三聚体在不同波长下测得的基态恢复寿命的动力学数据拟合成三项和四项指数之和进行分析。最短寿命（约56皮秒）归因于一个单体中的βs----βf转移，由于新转移通道的开启，在三聚体中该寿命降至31皮秒。单体中第二快的成分（约151皮秒）初步归因于α和βf发色团之间的激发能分布，由于它们之间激发能的重新分布，在三聚体中该成分降至约117皮秒。来自某些发色团（如正在发光的α和β1发色团）的某些种类的不均匀性产生的两个长寿命成分（单体约为690皮秒和1385皮秒，三聚体约为620皮秒和1320皮秒），在单体和三聚体中均显示出1:2的等幅比。
