Studies on the Structure and Function of Photosystem I Reaction Center Complex.

研究了菠菜类囊体膜光系统I （PSI）复合物的结构和功能。PSI配合物的光抑制光照导致二级电子受体Al失活，反应中心蛋白降解，而初级供体p7002没有损失。为了研究质体青素与PSI复合物的相互作用，采用EDC化学交联技术、抗PSI- f和抗质体青素抗血清免疫染色法检测其可及性。这些数据表明PSI-F亚基上存在两个质体青素结合位点。利用飞秒瞬态吸收光谱研究了菠菜、绿藻和蓝藻中PSI配合物的一次能量和电子转移过程。将PSI反应中心（RC）复合体重组为磷脂酰胆碱脂质体，经胰蛋白酶处理，得到的多肽片段用氨基酸测序仪进行分析。这些结果支持了x射线晶体学提出的PSI RC蛋白的新折叠模型。

Structure and function of photosystem I (PSI) complexes from spinach thylakoid membranes have been studied.1. Photoinhibitory illumination of PSI complexes caused an inactivation of the secondary electron acceptor, Al and the degradation of the reaction center proteins with no loss of the primary donor, P700.2. To investigate the interaction between plastocyanin and PSI complex, chemical cross-linking technique with EDC,and immunostaining with anti-PSI-F-and antiplastocyain antisera were used for a probe of their accessibility. The data suggest the presence of two plastocyanin binding sites on PSI-F subunit.3. Femtosecond transient absorption spectroscopy has been used to investigate the primary energy and electron transfer processes in PSI complexes from spinach, green algae and cyanobacterria.4. PSI reaction center (RC) complex reconstituted into phosphatidylcholine liposomes was treated with trypsin and the polypeptide fragments, thus obtauned, were analyzed by amino acid sequencer. The results support the new folding model for PSI RC proteins proposed from X-ray crystallography.