一项关于过氧化物酶催化酪氨酸假定羟基化反应的研究。
A study of the supposed hydroxylation of tyrosine catalysed by peroxidase.
作者信息
Smith P I, Swan G A
出版信息
Biochem J. 1976 Feb 1;153(2):403-8. doi: 10.1042/bj1530403.
The claim that peroxidase (rather than tyrosinase) is the enzyme responsible for the conversion of tyrosine into dopa (3,4-dihydroxyphenylalanine) in melanogenesis was investigated. The spectral changes that occurred during the action of horseradish peroxidase in the presence of H2O2 on dopa, tyrosine and mixtures of dopa with tyrosine or other phenolic compounds were studied. The effect of ascorbic acid or dihydroxyfumaric acid on some of these changes was also investigated. No evidence was found that tyrosine was hydroxylated by peroxidase in the presence of H2O2 and dopa as cofactor, although tyrosine or other phenolic compounds increased the rate of oxidation of dopa to dopachrome (indoline-5,6-quinone-2-carboxylic acid). Peroxidase was, however, effective in oxidizing tyrosine to dopa in the presence of dihydroxyfumaric acid and oxygen.
研究了关于在黑色素生成过程中，过氧化物酶（而非酪氨酸酶）是负责将酪氨酸转化为多巴（3,4 - 二羟基苯丙氨酸）的酶这一说法。研究了辣根过氧化物酶在H2O2存在下作用于多巴、酪氨酸以及多巴与酪氨酸或其他酚类化合物混合物时发生的光谱变化。还研究了抗坏血酸或二羟基富马酸对其中一些变化的影响。未发现有证据表明在H2O2和多巴作为辅因子存在的情况下，酪氨酸会被过氧化物酶羟基化，尽管酪氨酸或其他酚类化合物会提高多巴氧化为多巴色素（吲哚 - 5,6 - 醌 - 2 - 羧酸）的速率。然而，在二羟基富马酸和氧气存在的情况下，过氧化物酶能有效地将酪氨酸氧化为多巴。
Zotero 插件