Hansson C, Rorsman H, Rosengren E
Acta Derm Venereol. 1980;60(5):399-402.
Oxidation of 5-S-cysteinyldopa by mushroom tyrosinase was studied by measuring 5-S-cysteinyldopa consumption with HPLC. 5-S-cysteinyldopa was found to be a substrate for tyrosinase, but our results suggests that a self-catalysed oxidation induced by enzymatically formed 5-S-cysteinyl dopaquinone also takes place. Dopa oxidation by tyrosinase was determined by measuring substrate consumption with HPLC. The oxidation of 5-S-cysteinyldopa was markedly accelerated in the presence of dopa. This could be explained by dopaquinone oxidation of 5-S-cysteinyldopa, which has a lower oxidation potential than dopa.
通过高效液相色谱法（HPLC）测定5-S-半胱氨酰多巴的消耗，研究了蘑菇酪氨酸酶对5-S-半胱氨酰多巴的氧化作用。发现5-S-半胱氨酰多巴是酪氨酸酶的底物，但我们的结果表明，由酶促形成的5-S-半胱氨酰多巴醌诱导的自催化氧化也会发生。通过HPLC测定底物消耗来确定酪氨酸酶对多巴的氧化作用。在多巴存在下，5-S-半胱氨酰多巴的氧化明显加速。这可以用5-S-半胱氨酰多巴的多巴醌氧化来解释，其氧化电位低于多巴。
