Tyrosinases catalyse both the cresolase and catecholase reactions for the formation of reactive compounds which are very important for industrial applications. In this study, we describe a proteolytic activity of tyrosinases. Two different tyrosinases originating from mushroom and apple are able to cleave the carboxylesterase EstA. The cleavage reaction correlates with the integrity of the active site of tyrosinase and is independent of other possible influencing factors, which could be present in the reaction. Therefore, the cleavage of EstA represents a novel functionality of tyrosinases. EstA was previously reported to degrade synthetic polyesters, albeit slowly. However, the EstA truncated by tyrosinase shows higher degradation activity on the non-biodegradable polyester polyethylene terephthalate (PET), which is a well-established environmental threat.

酪氨酸酶催化甲酚酶和儿茶酚酶反应，形成反应性化合物，这对于工业应用非常重要。在这项研究中，我们描述了酪氨酸酶的蛋白水解活性。源自蘑菇和苹果的两种不同的酪氨酸酶能够裂解羧酸酯酶 EstA。裂解反应与酪氨酸酶活性位点的完整性相关，并且独立于反应中可能存在的其他可能的影响因素。因此，EstA 的裂解代表了酪氨酸酶的新功能。此前有报道称 EstA 会降解合成聚酯，尽管速度很慢。然而，被酪氨酸酶截短的 EstA 对不可生物降解的聚酯聚对苯二甲酸乙二醇酯 (PET) 表现出更高的降解活性，而 PET 是一种公认​​的环境威胁。