裂解多糖单加氧酶AfLPMO7的酶学特性研究

Enzymatic characterization of lytic polysaccharide monooxygenase AfLPMO7

为了加深对裂解多糖单加氧酶的研究,表达了来源于Aspergillus.fumigatus Z5的裂解多糖单加氧酶AfLPMO7。底物吸附实验表明其对磷酸溶胀纤维素(PASC)具有较强的结合能力,且能直接作用于PASC和木聚糖(Xylan)并产生还原糖;糖化实验表明其能有效协助纤维素酶水解天然底物水稻秸秆、小麦秸秆和玉米秸秆,分别最大提高111.89%、38.82%和50.95%;动力学实验表明其对2,6-二甲基苯酚(2,6-DMP)具有较强的氧化能力,Vmax值为109.99±3.91 U/g;自动建模和分子对接表明其催化中心和底物结合中心不一致。

To improve the degradation efficiency of cellulose,the lytic polysaccharide monooxygenase AfLPMO7,derived from Aspergillus.fumigatus Z5,was expressed.The result of substrate binding experiments showed that AfLPMO7 had a strong binding ability to phosphoric acid swollen cellulose(PASC),which also could directly act on PASC and Xylan and produce reducing sugars.The saccharification experiments showed that AfLPMO7 could effectively assist the cellulase to hydrolyze the natural substrates of rice straw,wheat straw and corn straw,the maximum increases were 111.89%,38.82%and 50.95%,respectively.Kinetic experiments showed that AfLPMO7 had the relatively strong oxidative capacity for 2,6-DMP,the V_(max)value was 109.99±3.91 U/g.Automated modeling and molecular docking suggested the zones were different for catalytic and substrate binding centers.