Enzymes are among the most studied biological molecules because better understanding enzymes structure and activity will shed more light on their biological processes and regulation; from a biotechnological point of view there are many examples of enzymes used with the aim to obtain new products and/or to make industrial processes less invasive towards the environment. Enzymes are known for their high specificity in the recognition of a substrate but considering the particular features of an increasing number of enzymes this is not completely true, in fact, many enzymes are active on different substrates: this ability is called enzyme promiscuity. Usually, promiscuous activities have significantly lower kinetic parameters than to that of primary activity, but they have a crucial role in gene evolution. It is accepted that gene duplication followed by sequence divergence is considered a key evolutionary mechanism to generate new enzyme functions. In this way, promiscuous activities are the starting point to increase a secondary activity in the main activity and then get a new enzyme. The primary activity can be lost or reduced to a promiscuous activity. In this review we describe the differences between substrate and enzyme promiscuity, and its rule in gene evolution. From a practical point of view the knowledge of promiscuity can facilitate the in vitro progress of proteins engineering, both for biomedical and industrial applications. In particular, we report cases regarding esterases, phosphotriesterases and cytochrome P450.

酶是研究最深入的生物分子之一，因为对酶的结构和活性有更深入的了解将使人们对其酶的生物过程和调控有更多的了解。从生物技术的角度来看，有许多酶的例子，目的是获得新产品和/或使工业过程对环境的侵害较小。酶以其在识别底物方面的高特异性而著称，但考虑到越来越多的酶的特殊特征，这并不完全正确，实际上，许多酶在不同的底物上具有活性：这种能力称为酶混杂。通常，混杂活动的动力学参数明显低于主要活动，但它们在基因进化中具有至关重要的作用。公认的是，基因复制继之以序列差异被认为是产生新酶功能的关键进化机制。这样，混杂活动是在主要活动中增加次要活动并获得新酶的起点。主要活动可能会丢失或减少为混杂活动。在这篇综述中，我们描述了底物和酶混杂之间的差异，及其在基因进化中的规律。从实践的角度来看，对于生物医学和工业应用，混杂的知识可以促进蛋白质工程的体外进展。特别是，我们报告了有关酯酶，磷酸三酯酶和细胞色素P450的病例。混杂活动是在主要活动中增加次要活动然后获得新酶的起点。主要活动可能会丢失或减少为混杂活动。在这篇综述中，我们描述了底物和酶混杂之间的差异，及其在基因进化中的规律。从实践的角度来看，对于生物医学和工业应用，混杂的知识可以促进蛋白质工程的体外进展。特别是，我们报告了有关酯酶，磷酸三酯酶和细胞色素P450的病例。混杂活动是在主要活动中增加次要活动然后获得新酶的起点。主要活动可能会丢失或减少为混杂活动。在这篇综述中，我们描述了底物和酶混杂之间的差异，及其在基因进化中的规律。从实践的角度来看，对于生物医学和工业应用，混杂的知识可以促进蛋白质工程的体外进展。特别是，我们报告了有关酯酶，磷酸三酯酶和细胞色素P450的病例。及其在基因进化中的规则 从实践的角度来看，对于生物医学和工业应用，混杂的知识可以促进蛋白质工程的体外进展。特别是，我们报告了有关酯酶，磷酸三酯酶和细胞色素P450的病例。及其在基因进化中的规则 从实践的角度来看，对于生物医学和工业应用，混杂的知识可以促进蛋白质工程的体外进展。特别是，我们报告了有关酯酶，磷酸三酯酶和细胞色素P450的病例。