解脂耶氏酵母脂肪酶Lip2的表面展示及其酶学性质

Cell Surface Display of Yarrowia lipolytica Lipase Lip2 by Saccharomyces cerevisiae and Its Practical Properties

摘要:

表面展示酶作为全细胞催化剂具备诸如能提高酶的稳定性、省去纯化过程、节约成本等优点。脂肪酶是应用最为广泛的工业酶之一。本研究利用酿酒酵母细胞壁蛋白Cwp2作为锚定蛋白, 将解脂耶氏酵母脂肪酶Lip2展示在酿酒酵母细胞表面, 以制备脂肪酶全细胞催化剂。Lip2被融合到Cwp2的N端, Cwp2通过其C端的GPI锚定信号共价结合到细胞壁上。表面展示的Lip2可以水解三丁酸甘油酯及对硝基苯酚辛酸酯(pNPC), 其pNPC水解酶活达到4.6 U/g干细胞。作为全细胞催化剂, 表面展示的Lip2具备良好的催化特征, 其最适温度为40°C, 最适pH为8.0, 同时还具备良好的有机溶剂稳定性。

Abstract:

Surface display of enzymes has been employed to improve stability of enzymes, and further save tedious purification process of enzymes to be used in conventional immobilization. Lipase is widely applied in industry. In this study, we constructed a Saccharomyces cerevisiae strain displaying lipase Lip2 from Yarrowia lipolytica on the cell surface. The gene encoding mature Lip2 was fused with the genes encoding the Kre1p leader sequence and the C-terminal domain of Cwp2 including the glycosylphosphatidylinositol(GPI)-anchor attachment signal. The Lip2 displayed on the yeast cell surface remained hydrolysis activity of lipase. The measured activity of the displayed lipase was 4.6 U/g dry cells. The displayed lipase was also characterized for its potentiality as a whole-cell biocatalyst. Its maximal activity was observed at 40°C and pH 8.0, and it exhibited good thermostability and high tolerance to organic solvent.