A lytic polysaccharide monooxygenase from Myceliophthora thermophila and its synergism with cellobiohydrolases in cellulose hydrolysis
A lytic polysaccharide monooxygenase from Myceliophthora thermophila and its synergism with cellobiohydrolases in cellulose hydrolysis
复制标题
嗜热毁丝霉的裂解性多糖单加氧酶及其与纤维二糖水解酶在纤维素水解中的协同作用
DOI：
10.1016/j.ijbiomac.2019.08.004
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发表时间：
2019
影响因子：
8.2
通讯作者：
Heng Yin
中科院分区：
文献类型：
--
作者：
Haichuan Zhou;Tang Li;Zuochen Yu;Jiu Ju;Huiyan Zhang;Haidong Tan;Kuikui Li;Heng Yin
溶解性多糖单加氧酶（LPMO）因其独特的氧化降解碳水化合物的机制和在生物炼制中的潜在应用而受到广泛关注。本研究对嗜热毁丝霉LPMO进行了鉴定，命名为MtLPMO 9 L。该酶的结构模型表明，它属于C1-氧化LPMO，在L3环中没有额外的螺旋，在L2环中也没有额外的环区。这随后通过酶测定证实，因为MtLPMO 9 L仅作用于纤维素并产生C1-氧化纤维寡糖。协同实验表明，MtLPMO 9 L显著提高了CBH II的水解效率。与此相反，当使用MtLPMO 9 L和CBHI组合时，观察到抑制作用而不是协同作用。改变MtLPMO 9 L与CBHI的孵育时间和浓度比可减弱其抑制作用。这一发现表明MtLPMO 9 L和两种CBH之间存在不同的协同作用细节，这意味着纤维素酶混合物的组成可能需要重新考虑。
Lytic polysaccharide monooxygenases (LPMOs) have attracted vast attention because of their unique mechanism of oxidative degradation of carbohydrate polymers and the potential application in biorefineries. This study characterized a novel LPMO fromMyceliophthora thermophila, denotedMtLPMO9L. The structure model of the enzyme indicated that it belongs to the C1-oxidizing LPMO, which has neither an extra helix in the L3 loop nor extra loop region in the L2 loop. This was confirmed subsequently by the enzymatic assays sinceMtLPMO9L only acts on cellulose and generates C1-oxidized cello-oligosaccharides. Moreover, synergetic experiments showed thatMtLPMO9L significantly improves the efficiency of cellobiohydrolase (CBH) II. In contrast, the inhibitory rather than synergetic effect was observed when combining usedMtLPMO9L and CBHI. Changing the incubation time and concentration ratio ofMtLPMO9L and CBHI could attenuate the inhibitory effects. This discovery suggests a different synergy detail betweenMtLPMO9L and two CBHs, which implies that the composition of cellulase cocktails may need reconsideration.