Margarita Salas Center for Biological Research, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain.
Biomolecules. 2023 Nov 28;13(12):1716. doi: 10.3390/biom13121716.
Multicopper oxidases (MCOs) share a common catalytic mechanism of activation by oxygen and cupredoxin-like folding, along with some common structural determinants. Laccases constitute the largest group of MCOs, with fungal laccases having the greatest biotechnological applicability due to their superior ability to oxidize a wide range of aromatic compounds and lignin, which is enhanced in the presence of redox mediators. The adaptation of these versatile enzymes to specific application processes can be achieved through the directed evolution of the recombinant enzymes. On the other hand, their substrate versatility and the low sequence homology among laccases make their exact classification difficult. Many of the ever-increasing amounts of MCO entries from fungal genomes are automatically (and often wrongly) annotated as laccases. In a recent comparative genomic study of 52 basidiomycete fungi, MCO classification was revised based on their phylogeny. The enzymes clustered according to common structural motifs and theoretical activities, revealing three novel groups of laccase-like enzymes. This review provides an overview of the structure, catalytic activity, and oxidative mechanism of fungal laccases and how their biotechnological potential as biocatalysts in industry can be greatly enhanced by protein engineering. Finally, recent information on newly identified MCOs with laccase-like activity is included.
多铜氧化酶 (MCOs) 具有共同的氧激活催化机制和类似于铜蓝蛋白的折叠，同时具有一些共同的结构决定因素。漆酶构成了 MCOs 中最大的一组，由于其能够氧化广泛的芳香族化合物和木质素的卓越能力，真菌漆酶具有最大的生物技术适用性，而在存在氧化还原介体的情况下，其能力会进一步增强。通过对重组酶的定向进化，可以使这些多功能酶适应特定的应用过程。另一方面，由于它们的底物通用性和漆酶之间的低序列同源性，使得对其进行准确分类变得困难。从真菌基因组中不断增加的 MCO 序列中，有许多是自动（且通常是错误的）注释为漆酶的。在最近对 52 种担子菌真菌的比较基因组研究中，根据其系统发育对 MCO 分类进行了修订。这些酶根据共同的结构基序和理论活性聚类，揭示了三种新型漆酶样酶类。本文综述了真菌漆酶的结构、催化活性和氧化机制，以及如何通过蛋白质工程极大地增强其作为工业生物催化剂的生物技术潜力。最后，还包括了关于具有漆酶样活性的新鉴定 MCO 的最新信息。
