The Podospora anserina lytic polysaccharide monooxygenase PaLPMO9H catalyzes oxidative cleavage of diverse plant cell wall matrix glycans.
The Podospora anserina lytic polysaccharide monooxygenase PaLPMO9H catalyzes oxidative cleavage of diverse plant cell wall matrix glycans.
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DOI：
10.1186/s13068-017-0749-5
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发表时间：
2017
影响因子：
6.3
通讯作者：
Berrin JG
中科院分区：
文献类型：
--
作者：
Fanuel M;Garajova S;Ropartz D;McGregor N;Brumer H;Rogniaux H;Berrin JG
最近，由于催化多糖氧化裂解的裂解多糖单加氧酶（LPMO）的发现，植物生物质的酶促转化发生了革命性的变化。这些强大的酶由大量真菌腐生菌分泌，是用于工业生物质转化的商业酶混合物的重要组成部分。在鹅足孢菌基因组编码的 33 个 AA9 LPMO 中，PaLPMO9H 酶催化纤维素和纤维寡糖的混合 C1/C4 氧化裂解。已提出 PaLPMO9H 对几种半纤维素的活性，但切割的区域选择性仍有待确定。在本研究中，我们使用串联质谱和离子淌度质谱研究了 PaLPMO9H 对混合键葡聚糖、木葡聚糖和葡甘露聚糖的活性。对已发布产品的结构分析表明，PaLPMO9H 催化混合键葡聚糖的 C4 氧化裂解以及葡甘露聚糖和木葡聚糖的混合 C1/C4 氧化裂解。偕二醇和酮在产物的非还原端产生，而醛糖酸在产物的还原端产生。 PaLPMO9H 靶向多糖的能力（其连接、糖苷组成和/或侧链的存在与纤维素不同）在分解代谢高度可变的多糖时可能有利于这种粪真菌，并且有利于在生物精炼厂中开发优化的酶混合物。本文的在线版本 (doi:10.1186/s13068-017-0749-5) 包含补充材料，可供授权用户使用。
The enzymatic conversion of plant biomass has been recently revolutionized by the discovery of lytic polysaccharide monooxygenases (LPMO) that catalyze oxidative cleavage of polysaccharides. These powerful enzymes are secreted by a large number of fungal saprotrophs and are important components of commercial enzyme cocktails used for industrial biomass conversion. Among the 33 AA9 LPMOs encoded by the genome of Podospora anserina, the PaLPMO9H enzyme catalyzes mixed C1/C4 oxidative cleavage of cellulose and cello-oligosaccharides. Activity of PaLPMO9H on several hemicelluloses has been suggested, but the regioselectivity of the cleavage remained to be determined. In this study, we investigated the activity of PaLPMO9H on mixed-linkage glucans, xyloglucan and glucomannan using tandem mass spectrometry and ion mobility–mass spectrometry. Structural analysis of the released products revealed that PaLPMO9H catalyzes C4 oxidative cleavage of mixed-linkage glucans and mixed C1/C4 oxidative cleavage of glucomannan and xyloglucan. Gem-diols and ketones were produced at the non-reducing end, while aldonic acids were produced at the reducing extremity of the products. The ability of PaLPMO9H to target polysaccharides, differing from cellulose by their linkages, glycosidic composition and/or presence of sidechains, could be advantageous for this coprophilous fungus when catabolizing highly variable polysaccharides and for the development of optimized enzyme cocktails in biorefineries. The online version of this article (doi:10.1186/s13068-017-0749-5) contains supplementary material, which is available to authorized users.