Ito S, Kato T, Shinpo K, Fujita K
Biochem J. 1984 Sep 1;222(2):407-11. doi: 10.1042/bj2220407.
A simple and rapid method was developed for the determination of 3,4-dihydroxyphenylalanine (dopa) and 5-S-cysteinyl-3,4-dihydroxyphenylalanine (5-S-cysteinyldopa) in proteins with the use of high-pressure liquid chromatography. With this method, it is demonstrated that mushroom tyrosinase can catalyse hydroxylation of tyrosine residues in proteins to dopa and subsequent oxidation to dopaquinone residues. The dopaquinone residues in proteins combine with cysteine residues to form 5-S-cysteinyldopa in bovine serum albumin and yeast alcohol dehydrogenase, whereas dopa is the major product in bovine insulin, which lacks cysteine residues.
开发了一种简单快速的方法，利用高压液相色谱法测定蛋白质中的3,4-二羟基苯丙氨酸（多巴）和5-S-半胱氨酰-3,4-二羟基苯丙氨酸（5-S-半胱氨酰多巴）。用该方法证明，蘑菇酪氨酸酶可催化蛋白质中酪氨酸残基羟基化为多巴，并随后氧化为多巴醌残基。蛋白质中的多巴醌残基与半胱氨酸残基结合，在牛血清白蛋白和酵母乙醇脱氢酶中形成5-S-半胱氨酰多巴，而多巴是牛胰岛素中的主要产物，牛胰岛素缺乏半胱氨酸残基。
