Mammalian tyrosinase. A comparison of tyrosine hydroxylation and melanin formation.
Mammalian tyrosinase. A comparison of tyrosine hydroxylation and melanin formation.
复制标题
哺乳动物酪氨酸酶。
作者：
V. Hearing;T. M. Ekel
1.从正常C57 B1小鼠中分离出黑素体酪氨酸酶，并对该酶的酪氨酸羟基化和多巴（3，4-二羟基苯丙氨酸）氧化活性进行了比较。2.结果表明，在没有多巴辅因子的情况下，这种酶能够酪氨酸羟基化，但很少有随后的多巴氧化和黑色素形成。3.这种酶作用机制可能在黑色素形成的细胞内调节中起重要作用。4.此外，多巴除了作为反应的氢供体的已知活性外，似乎还作为酪氨酸酶酪氨酸羟基化的正变构效应物。
1. Melanosomal tyrosinase was isolated from normal C57B1 mice, and a comparison of the tyrosine-hydroxylation and dopa (3,4-dihydroxyphenylalanine)-oxidation activities of this enzyme was made. 2. The results indicate that in the absence of dopa cofactor, this enzyme is capable of tyrosine hydroxylation, but with very little subsequent dopa oxidation and melanin formation. 3. This mechanism of enzyme action may play an important role in the intracellular regulation of melanin formation. 4. Further, dopa appears to act as a positive allosteric effector for tyrosine hydroxylation by tyrosinase, in addition to its known activity as a hydrogen donor for the reaction.