Modification of halogen specificity of a vanadium-dependent bromoperoxidase
Modification of halogen specificity of a vanadium-dependent bromoperoxidase
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DOI：
10.1110/ps.03496004
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发表时间：
2004-06-01
期刊：
影响因子：
8
通讯作者：
Izumi, Y
中科院分区：
文献类型：
--
作者：
Ohshiro, T;Littlechild, J;Izumi, Y
来自海洋藻类 Corallina pilulifera 的钒依赖性溴过氧化物酶 (BPO) 的卤化物特异性已通过单个氨基酸取代而改变。残基 R397 已被其他 19 个氨基酸取代。突变酶 R397W 和 R397F 显示出显着的氯过氧化物酶 (CPO) 活性以及 BPO 活性。这些突变酶被纯化并研究了它们的特性。 R397W和R397F酶的CPO活性的最大速度分别为31.2和39.2单位/mg，Cl-的K-m值分别为780mM和670mM。与天然酶不同，两种突变酶均被 NaN3 抑制。在R397W酶的情况下，与R397F和野生型酶相比，钒酸盐进入活性位点的掺入率较低。这些结果支持钒卤过氧化物酶的催化裂隙内存在特定的卤素结合位点。
The halide specificity of vanadium-dependent bromoperoxidase (BPO) from the marine algae, Corallina pilulifera, has been changed by a single amino acid substitution. The residue R397 has been substituted by the other 19 amino acids. The mutant enzymes R397W and R397F showed significant chloroperoxidase (CPO) activity as well as BPO activity. These mutant enzymes were purified and their properties were investigated. The maximal velocities of CPO activities of the R397W and R397F enzymes were 31.2 and 39.2 units/mg, and the K-m values for Cl- were 780 mM and 670 mM, respectively. Unlike the native enzyme, both mutant enzymes were inhibited by NaN3. In the case of the R397W enzyme, the incorporation rate of vanadate into the active site was low, compared with the R397F and the wild-type enzyme. These results supported the existence of a specific halogen binding site within the catalytic cleft of vanadium haloperoxidases.