Bricker T M, Frankel L K
Arch Biochem Biophys. 1987 Jul;256(1):295-301. doi: 10.1016/0003-9861(87)90449-8.
A monoclonal antibody, FAC2, was isolated by immunization of mice with a Photosystem II core preparation followed by splenic fusion and standard monoclonal antibody screening and production techniques. This antibody recognizes the 49-kDa polypeptide of Photosystem II which is the apoprotein of CPal. The antigenic determinant recognized by this antibody lies on a cyanogen bromide fragment which appears as a doublet with an apparent molecular mass of 14.5 kDa. FAC2 was used to follow the effects of trypsin on the 49-kDa polypeptide in a membrane environment. Our results indicate that the extrinsic polypeptides of Photosystem II which are known to be involved in oxygen evolution protect the 49-kDa polypeptide from tryptic attack. Additionally, Photosystem II membranes which are treated with alkaline Tris exhibit a large increase in the ability to bind FAC2. This increase is not observed with membranes treated with calcium chloride or sodium chloride. These results indicate that the 49-kDa polypeptide may be at least structurally associated with the component(s) responsible for oxygen evolution.
通过用光合系统II核心制剂免疫小鼠，随后进行脾融合以及标准的单克隆抗体筛选和生产技术，分离出了一种单克隆抗体FAC2。该抗体识别光合系统II的49 kDa多肽，它是CPal的脱辅基蛋白。此抗体识别的抗原决定簇位于一个溴化氰片段上，该片段呈现为一个双峰，表观分子量为14.5 kDa。FAC2被用于追踪胰蛋白酶在膜环境中对49 kDa多肽的作用。我们的结果表明，已知参与氧气释放的光合系统II的外在多肽可保护49 kDa多肽免受胰蛋白酶攻击。此外，用碱性Tris处理的光合系统II膜结合FAC2的能力大幅增加。用氯化钙或氯化钠处理的膜未观察到这种增加。这些结果表明，49 kDa多肽可能至少在结构上与负责氧气释放的成分相关。
