Garzillo A M, Colao M C, Buonocore V, Oliva R, Falcigno L, Saviano M, Santoro A M, Zappala R, Bonomo R P, Bianco C, Giardina P, Palmieri G, Sannia G
Dipartimento di Agrobiologia e Agrochimica, Università della Tuscia, Viterbo, Italy.
J Protein Chem. 2001 Apr;20(3):191-201. doi: 10.1023/a:1010954812955.
A comparative study has been performed on five native laccases purified from the three basidiomycete fungi Pleurotus ostreatus, Rigidoporus lignosus, and Trametes trogii to relate their different catalytic capacities to their structural properties. Spectroscopic absorption features and EPR spectra at various pH values of the five enzymes are very similar and typical of the blue oxidases. The analysis of the dependence of kinetic parameters on pH suggested that a histidine residue is involved in the binding of nonphenolic substrates, whereas both a histidine and an acidic residue may be involved in the binding of phenolic compounds. His and an Asp residue are indeed found at the bottom of a cavity which may be regarded as a suitable substrate channel for approaching to type 1 copper in the 3D homology models of the two laccases from Pleuorotus ostreatus (POXC and POXAlb) whose sequences are known.
对从三种担子菌平菇、木蹄层孔菌和毛栓菌中纯化得到的五种天然漆酶进行了比较研究，以将它们不同的催化能力与其结构特性联系起来。这五种酶在不同pH值下的光谱吸收特征和电子顺磁共振光谱非常相似，是典型的蓝色氧化酶。动力学参数对pH的依赖性分析表明，一个组氨酸残基参与非酚类底物的结合，而一个组氨酸残基和一个酸性残基可能参与酚类化合物的结合。在平菇的两种漆酶（POXC和POXAlb）的三维同源模型中，确实在一个腔的底部发现了组氨酸和一个天冬氨酸残基，该腔可被视为一个合适的底物通道，用于接近1型铜，这两种漆酶的序列是已知的。
