Theoretical Studies on the Structural and Magnetic Property of Arginase Active Site
Theoretical Studies on the Structural and Magnetic Property of Arginase Active Site
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精氨酸酶活性位点结构及磁性的理论研究
DOI：
10.1080/10610278.2010.506552
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
et al
中科院分区：
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作者：
Y.Kitagawa;M.Okumura;K.Yamaguchi;et al
从结构和磁性出发，研究了精氨酸酶活性中心两个锰离子之间的溶剂分子(WB)的化学物种。在UBH和HLYP理论水平上计算的磁耦合常数(JAB)值分别为−和1.9 cm−/1(WB=0.H2O)和−(5.7 cm−/1)(WB/−)。与实验值(JAB=∼/−=2.0 cm−/1)相比，在初始结构中，H2O是最有可能的WB候选者。自然轨道分析表明，WB对保持Mn-O(WB)-Mn核的几何构型具有重要作用，而不是调节超交换作用。结果表明，WB不一定要转移到一个锰离子上才能引发水解反应。
The chemical species of solvent molecule (WB) between two manganese ions in the active site of arginase is investigated based on the structural and magnetic property. The calculated magnetic coupling constant (Jab) values at UBH&HLYP level of theory are − 1.9 cm− 1for WB = H2O and − 5.7 cm− 1for WB = OH−, respectively. In comparison with the experimental value (Jab= ∼ − 2.0 cm− 1), H2O is the most likely candidate to WB in the initial structure. Natural orbital analyses reveal that WB plays an important role for keeping the geometry of the Mn–O(WB)–Mn core rigid rather than mediating superexchange interaction. The result indicates that WB does not have to shift to one Mn ion as an initiation of the hydrolysis reaction.