Mapping the Long-Range Electron Transfer Route in Ligninolytic Peroxidases
Mapping the Long-Range Electron Transfer Route in Ligninolytic Peroxidases
复制标题
绘制木质素分解过氧化物酶中的长程电子转移途径图
DOI：
10.1021/acs.jpcb.7b00835
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发表时间：
2017-04-27
影响因子：
3.3
通讯作者：
Guallar, Victor
中科院分区：
文献类型：
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作者：
Acebes, Sandra;Ruiz-Duenas, Francisco J.;Guallar, Victor
结合计算分析与定点诱变，我们研究了远程电子转移途径中的通用和木质素过氧化物酶，两种酶的生物技术的兴趣，发挥了关键作用的真菌降解的庞大的木质素分子在植物生物质。计算机模拟研究建立了两种可能的电子转移途径，从表面色氨酸残基开始，先前确定为负责氧化的大体积木质素聚合物。此外，在这两种酶中，第二个掩埋的色氨酸残基作为顶部电子转移载体出现，表明一种途径的流行。多功能过氧化物酶的定点诱变（来自Pleuerynthalus）使我们能够证实计算分析和掩埋的色氨酸（Trp244）和相邻的苯丙氨酸残基（Phe198），以及表面色氨酸在电子转移中所起的作用。这三个芳香族残基在所有分析的序列中高度保守（总共多达169个）。木质素过氧化物酶的表面（Trp171）和埋藏（Trp251）色氨酸残基的重要性也已被证实的定向诱变的黄孢原毛革菌酶。总的来说，相结合的程序确定了类似的电子转移途径的远程氧化机制的木质素分解过氧化物酶，构成了一个很好的例子，如何计算分析避免了广泛的试错诱变实验。
Combining a computational analysis with site-directed mutagenesis, we have studied the long-range electron transfer pathway in versatile and lignin peroxidases, two enzymes of biotechnological interest that play a key role for fungal degradation of the bulky lignin molecule in plant biomass. The in silico study established two possible electron transfer routes starting at the surface tryptophan residue previously identified as responsible for oxidation of the bulky lignin polymer. Moreover, in both enzymes, a second buried tryptophan residue appears as a top electron transfer carrier, indicating the prevalence of one pathway. Site-directed mutagenesis of versatile peroxidase (from Pleurotus eryngii) allowed us to corroborate the computational analysis and the role played by the buried tryptophan (Trp244) and a neighbor phenylalanine residue (Phe198), together with the surface tryptophan, in the electron transfer. These three aromatic residues are highly conserved in all the sequences analyzed (up to a total of 169). The importance of the surface (Trp171) and buried (Trp251) tryptophan residues in lignin peroxidase has been also confirmed by directed mutagenesis of the Phanerochaete chrysosporium enzyme. Overall, the combined procedure identifies analogous electron transfer pathways in the long-range oxidation mechanism for both ligninolytic peroxidases, constituting a good example of how computational analysis avoids making extensive trial-error mutagenic experiments.