High-valent intermediates in the reaction of N alpha-acetyl microperoxidase-8 with hydrogen peroxide: models for compounds 0, I and II of horseradish peroxidase.
High-valent intermediates in the reaction of N alpha-acetyl microperoxidase-8 with hydrogen peroxide: models for compounds 0, I and II of horseradish peroxidase.
复制标题
N α-乙酰基微过氧化物酶-8 与过氧化氢反应中的高价中间体：辣根过氧化物酶化合物 0、I 和 II 的模型。
DOI：
10.1016/0006-291x(91)91717-q
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发表时间：
1991
影响因子：
3.1
通讯作者：
VanWart,HE
中科院分区：
文献类型：
--
作者：
Wang,JS;Baek,HK;VanWart,HE
N-acetyl microperoxidase-8 (Ac-MP-8) is a water soluble, ferric heme model for the peroxidases. The reaction of Ac-MP-8 with H2O2in 10 mM potassium phosphate over the pH range of 7–11 gives rise sequentially to relatively stable green and red species with properties that closely mimic those of HRP compounds I and II, respectively. Low-temperature stopped-flow studies of this reaction carried out in 50% v/v methanol/10 mM potassium phosphate, pH*9.1 at -25.8°C indicate that the pseudo-first-order rate constant, kobs, that describes the formation of the green intermediate exhibits saturation kinetics as a function of [H2O2] with kobsmax= 95 s−1and KM= 87 mM. Rapid-scan studies carried out with [H2O2] = 200 mM at -38.0°C show that a compound 0 species with a characteristic band near 340 nm is formed whose conversion to the green species is rate limiting. Thus, Ac-MP-8 has high-valent forms that are models for all three known intermediates in the peroxidase cycle of horseradish peroxidase.
