Structural Basis for Catalytic Activation of Thiocyanate Hydrolase Involving Metal-Ligated Cysteine Modification
Structural Basis for Catalytic Activation of Thiocyanate Hydrolase Involving Metal-Ligated Cysteine Modification
复制标题
DOI：
10.1021/ja903979s
复制
发表时间：
2009-10-21
影响因子：
15
通讯作者：
Odaka, Masafumi
中科院分区：
文献类型：
--
作者：
Arakawa, Takatoshi;Kawano, Yoshiaki;Odaka, Masafumi
硫氰酸水解酶 (SCNase) 是腈水合酶蛋白家族的一员，每个蛋白均包含独特的 noncorrin 钴中心，具有两个翻译后修饰的半胱氨酸配体，分别为半胱氨酸-亚磺酸或-亚磺酸盐 (Cys-SO(H)) 和半胱氨酸-亚磺酸盐 (CYS-SO2-)。我们发现部分成熟的重组SCNase在储存过程中被激活。储存前后SCNase的晶体结构表明，γ CyS131的CYS-SO2修饰在储存前已完成，而γ Cys133的Cys-SO（H）修饰在储存过程中发生，当γ Cys133进一步氧化为CYS-SO2-时，SCNase活性受到抑制。催化活性与 γ Cys133 修饰程度之间的相关性表明，γ Cys133 的半胱氨酸磺酸修饰对于确定 SCNase 的活性至关重要。
Thiocyanate hydrolase (SCNase) is a member of a family of nitrile hydratase proteins, each of which contains a unique noncorrin cobalt center with two post-translationally modified cysteine ligands, cysteine-sulfenic acid or -sulfenate (Cys-SO(H)), and cysteine-sulfininate (CYS-SO2-), respectively. We have found that a partially matured recombinant SCNase was activated during storage The crystal structures of SCNase before and after storage demonstrated that CYS-SO2 modification of gamma CyS131 proceeded to completion prior to storage, while Cys-SO(H) modification of gamma Cys133 occurred during storage SCNase activity was suppressed when gamma Cys133 was further oxidized to CYS-SO2-. The correlation between the catalytic activity and the extent of the gamma Cys133 modification indicates that the cysteine sulfenic acid modification of gamma Cys133 is of primary importance in determining the activity of SCNase.