Johansson T, Welinder K G, Nyman P O
Department of Biochemistry, University of Lund, Sweden.
Arch Biochem Biophys. 1993 Jan;300(1):57-62. doi: 10.1006/abbi.1993.1008.
The basidiomycete Trametes versicolor, a white-rot fungus and potent degrader of lignin, produces multiple forms of extracellular peroxidases. Nine of these forms, six lignin peroxidases and three manganese(II) peroxidases, purified as described in the preceding paper, were characterized by amino-terminal sequencing, amino acid analyses, carbohydrate analyses, or peptide mapping. For two of the lignin peroxidase forms, tryptic peptides were isolated and sequenced to an extent corresponding to about 40 and 30%, respectively, of the primary structure. Eight of the nine peroxidases investigated were found to possess unique amino-terminal regions. A comparison of the sequences shows 57% of the residues to be identical, indicating a common ancestry for the lignin peroxidase and the manganese(II) peroxidase. The degree of identity among the five lignin peroxidases is about 80% and among the three manganese(II) peroxidases about 70%. Pairwise comparisons of the sequences disclosed that some of the lignin peroxidases are very closely related, either identical or differing only in a single amino acid residue of the thirty-five investigated. These close relationships are also supported by peptide mapping and by similarities in amino acid compositions. Tyr is absent in all isozymes. Lignin and manganese(II) peroxidases showed the presence of glucosamine and mannose in an amount corresponding to 3 to 6% of the molecular mass of the proteins. The carbohydrate compositions are compatible with the presence of 1, 2, and 3 sites of N-glycosylation. The results obtained strongly suggest that the complexity in the peroxidase pattern displayed by the fungus (T. Johansson and P.O. Nyman, Arch. Biochem. Biophys. 300, 49-56, 1993) can largely be accounted for by a heterogeneity at the gene level, probably in the form of multiple structural genes. Two recently published genes from genomic clones of T. versicolor are identical in sequence to two of the lignin peroxidases characterized here.
担子菌云芝是一种白腐真菌，也是木质素的高效降解菌，能产生多种形式的细胞外过氧化物酶。如前文所述纯化得到的其中9种形式，包括6种木质素过氧化物酶和3种锰（II）过氧化物酶，通过氨基末端测序、氨基酸分析、碳水化合物分析或肽图谱分析进行了表征。对于其中两种木质素过氧化物酶形式，分离并测序了胰蛋白酶肽段，测序程度分别约占一级结构的40%和30%。在所研究的9种过氧化物酶中，有8种具有独特的氨基末端区域。序列比较显示57%的残基相同，表明木质素过氧化物酶和锰（II）过氧化物酶有共同的祖先。5种木质素过氧化物酶之间的同一性程度约为80%，3种锰（II）过氧化物酶之间约为70%。序列的成对比较表明，一些木质素过氧化物酶密切相关，要么完全相同，要么在所研究的35个氨基酸残基中仅相差一个。这些密切关系也得到了肽图谱分析和氨基酸组成相似性的支持。所有同工酶中均不存在酪氨酸。木质素和锰（II）过氧化物酶显示存在氨基葡萄糖和甘露糖，其含量相当于蛋白质分子量的3%至6%。碳水化合物组成与存在1、2和3个N-糖基化位点相符。所得结果强烈表明，该真菌所显示的过氧化物酶模式的复杂性（T. Johansson和P.O. Nyman，《生物化学与生物物理学档案》300，49 - 56，1993）在很大程度上可能是由基因水平的异质性造成的，可能是以多个结构基因的形式。最近从云芝基因组克隆中发表的两个基因与这里表征的两种木质素过氧化物酶在序列上相同。
