Dynamic Carboxylate/Water Networks on the Surface of the PsbO Subunit of Photosystem II.
Dynamic Carboxylate/Water Networks on the Surface of the PsbO Subunit of Photosystem II.
复制标题
光系统 II PsbO 亚基表面的动态羧酸盐/水网络。
DOI：
10.1021/acs.jpcb.5b06594
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Bondar,Ana-Nicoleta
中科院分区：
文献类型：
--
作者：
Lorch,Sebastian;Capponi,Sara;Pieront,Florian;Bondar,Ana-Nicoleta
质子转移蛋白表面的带电基团簇可能参与质子转移。PsbO是光系统II的一个外在亚基，是通向催化位点的广泛氢键网络的一部分，是一种富含羧酸的蛋白质。这提出了一个重要的问题，即PsbO表面的特定羧酸基是否可以直接帮助质子从催化位置转移到本体。通过对PsbO在水溶液中的分子动力学模拟，我们发现在接近PsbO表面的地方，水分子的迁移率比在本体水中的要低。在PsbO对接和氢键与光系统II结合的位置，水分子的迁移率很低，我们确定了一个羧酸盐簇，它通过短的氢键水线持久地桥接羧酸盐。这种水桥接的羧酸簇对于质子转移和PsbO与光系统II的结合可能是重要的。
Clusters of charged groups on the surface of proton-transfer proteins may participate in proton transfers. PsbO, an extrinsic subunit of photosystem II, is a carboxylate-rich protein part of an extensive hydrogen-bond network leading to the catalytic site. This raises the important question as to whether specific clusters of carboxylate groups on the surface of PsbO may directly assist transfer of protons from the catalytic site to the bulk. From molecular dynamics simulations of PsbO in aqueous solution, we find that, close to the surface of PsbO, the mobility of water molecules is lower than that for bulk water. At the site where PsbO docks and hydrogen bonds to photosystem II, water molecules have low mobility, and we identify a carboxylate cluster with persistent bridging of the carboxylates via short hydrogen-bonding water wires. This water-bridged carboxylate cluster could be important for proton transfer and binding of PsbO to photosystem II.