Synthetically useful variants of industrial lipases from Burkholderia cepacia and Pseudomonas fluorescens
作者:Kazunori Yoshida、Masakazu Ono、Takahiro Yamamoto、Takashi Utsumi、Satoshi Koikeda、Tadashi Ema
DOI:10.1039/c7ob01823a
日期:——
Industrial enzymes lipase PS (LPS) and lipase AK (LAK), which originate from Burkholderia cepacia and Pseudomonas fluorescens, respectively, are synthetically useful biocatalysts. To strengthen their catalytic performances, we introduced two mutations into hot spots of the active sites (residues 287 and 290). The LPS_L287F/I290A double mutant showed high catalytic activity and enantioselectivity for
分别源自洋葱伯克霍尔德氏菌和荧光假单胞菌的工业酶脂肪酶PS(LPS)和脂肪酶AK(LAK)是合成有用的生物催化剂。为了增强其催化性能,我们在活性位点的热点(残基287和290)中引入了两个突变。LPS_L287F / I290A双突变体对不良底物表现出较高的催化活性和对映选择性,而野生型酶显示的底物活性非常低。LAK_V287F / I290A双突变体也是一种出色的生物催化剂,具有扩大的底物范围,与LPS_L287F / I290A双突变体相当。确定热力学参数以解决双重突变体的高对映选择性的起源。该ΔΔ ^ h ‡术语,而不是ΔΔ小号‡术语,为优势,这表明对映体选择性通过与周围Phe287和Ala290分子间的相互作用相关联的差分能量驱动。观察到了显着的溶剂作用,在e值与i-Pr 2 O中具有最高E值的溶剂的log P或ε值之间呈钟形分布。这表明具有适当疏水性和极性的有机溶剂可提供具有某