Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
Appl Microbiol Biotechnol. 2010 Oct;88(4):885-91. doi: 10.1007/s00253-010-2782-1. Epub 2010 Jul 31.
Lipase has been used widely in industry. In this study, we have constructed two recombinant Saccharomyces cerevisiae strains displaying two active lipases on the cell surface by cell surface engineering. The genes encoding Yarrowia lipolytica lipases Lip7 and Lip8 were fused with the gene encoding small binding subunit Aga2 of a-agglutinin. Localization of the Lip7 and Lip8 on the cell surface was confirmed by immunofluorescence microscopy. Besides, the putative signal sequences of Lip7 and Lip8 were removed to compare their effect on the activities of surface-displayed lipases. The results showed that the activities towards p-nitrophenyl caprylate of surface-displayed Lip7 and Lip8 were 283 U/g (dry cell) and 121 U/g (dry cell), much higher than that using Flo1 as anchor protein in Pichia pastoris, and the putative signal sequences have significant effect on the activities of the displayed lipases; when deleted, the lipases' activities were declined to 65 U/g (dry cell) and 80 U/g (dry cell), respectively. The displayed lipases exhibit a preference for middle chain fatty acids and a high thermal stability. Additionally, from the study, to surface-display a target protein, it is recommendable that the structure feature of the protein should be assayed through bioinformatics methods and then the cell wall proteins with the anchor domain far away from the activity center should be chosen as anchor proteins.
脂肪酶在工业中得到了广泛的应用。在这项研究中,我们通过细胞表面工程构建了两株重组酿酒酵母菌株,在细胞表面展示了两种活性脂肪酶。融合了脂肪酶 Lip7 和 Lip8 的基因编码与凝集素 Aga2 的小结合亚基基因编码融合。通过免疫荧光显微镜证实了 Lip7 和 Lip8 在细胞表面的定位。此外,还去除了 Lip7 和 Lip8 的假定信号序列,以比较它们对表面展示脂肪酶活性的影响。结果表明,表面展示的 Lip7 和 Lip8 对 p-硝基苯辛酸酯的活性分别为 283 U/g(干细胞)和 121 U/g(干细胞),明显高于使用巴斯德毕赤酵母的 Flo1 作为锚蛋白时的活性,而且假定的信号序列对展示脂肪酶的活性有显著影响;当信号序列被删除时,脂肪酶的活性分别下降到 65 U/g(干细胞)和 80 U/g(干细胞)。所展示的脂肪酶对中链脂肪酸具有偏好性和较高的热稳定性。此外,通过这项研究,建议在进行表面展示时,应通过生物信息学方法检测目标蛋白的结构特征,并选择远离活性中心的细胞壁蛋白作为锚蛋白。