Manganese-binding proteins of the oxygen-evolving complex.
Manganese-binding proteins of the oxygen-evolving complex.
复制标题
放氧复合物的锰结合蛋白。
DOI：
10.1021/bi00439a033
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发表时间：
1989
期刊：
影响因子：
2.9
通讯作者：
Frasch,WD
中科院分区：
文献类型：
--
作者：
Mei,R;Green,JP;Sayre,RT;Frasch,WD
M CaCl 2。条件被发现，其中超过一半的交联的蛋白质复合物中形成的PSII制剂保留的能力，催化水的氧化。该复合物由与D1和D2蛋白交联的P33和34-kDa蛋白组成，该蛋白的丰度低于其他三种蛋白。在用SDS溶解膜并通过制备型SDS-PAGE纯化后，复合物保留结合的锰并可催化H2 O2转化为O2。钙和氯化物增加了纯化的交联复合物的过氧化氢酶活性，而镧或羟胺废除的活动。通过使用H2 O2依赖性反应的比活性来跟踪交联复合物的纯化程度，确定最高度纯化的复合物含有0.34 pg锰/180 pg蛋白质。Mn/蛋白质的摩尔比计算为3.6至4.5，这取决于蛋白质亚基的假定化学计量。这里呈现的结果提供了直接的证据，即与P33交联的三种蛋白质中的一种或多种负责结合放氧复合物的锰。放氧复合物（OEC）1催化水氧化为分子氧，为光系统II（PSII）反应中心提供电子。PSII的光反应产生的氧化剂驱动了顺序推进
M CaCl2. Conditions were found in which more than half of the cross-linked protein complexes formed in the PSII preparations retained the ability to catalyze the oxidation of water. The complex is composed of the P33 cross-linked to the Dj and D2 proteins and a 34-kDa protein, which is present in lower abundance than the other three proteins. After solubilization of the membranes with SDS and purification by preparative SDS-PAGE, the complex retains bound manganese and can catalyze the conversion of H202 to 02. Calcium and chloride increased the catalase activity of the purified cross-linked complex while lanthanum or hydroxylamine abolished the activity. By use of the specific activity of the H202-dependent reaction to follow theextent of purification of the cross-linked complex, the most highly purified complex was determined to contain 0.34 pg of manganese/180 pg of protein. The mole ratio of Mn/protein was calculated to range from 3.6 to 4.5 depending on the assumed stoichiometry of the protein subunits. The results presented here provide direct evidence that one or more of the three proteins that have cross-linked to the P33 are responsible for binding the manganese of the oxygen-evolving complex. e oxygen-evolving complex (OEC) 1 catalyzes the oxidation of water to molecular oxygen in order to supply electronsto the photosystem II (PSII) reaction center. Oxidants generated by the photoreactions of PSII drive the sequential advancement