Lipase stereoselectivity and regioselectivity toward three isomers of dicaprin: A kinetic study by the monomolecular film technique
Lipase stereoselectivity and regioselectivity toward three isomers of dicaprin: A kinetic study by the monomolecular film technique
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DOI：
10.1002/chir.530070703
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发表时间：
1995-01-01
期刊：
影响因子：
2
通讯作者：
Verger, R
中科院分区：
文献类型：
--
作者：
Rogalska, E;Nury, S;Verger, R
在这里，我们提出了一个动力学研究的立体选择性和区域选择性的23个纯化的脂肪酶的动物和微生物来源。这项工作，关于脂肪酶-底物分子识别机制的一般性问题，使用纯二癸酸异构体：1，2-sn-二癸酸，2，3-sn-二癸酸和1，3-sn-二癸酸作为单分子膜在空气-水界面上展开。前两种异构体是光学活性的对映体（对映体），形成稳定的膜高达40 mN m（-1），而最后一种是一种前手性化合物，具有32 mN m（-1）的崩溃的表面压力。据我们所知，这是第一次报告使用三个甘油二酯异构体作为脂肪酶底物在相同的和受控的物理化学条件。测试的脂肪酶显示典型的行为，每种酶的特征，这使我们能够分类的脂肪酶组根据（1）作为表面压力的函数的酶速度的配置文件，（2）他们的喜好，为一个给定的甘油二酯异构体，定量使用新的参数称为立体选择性指数（S.L），邻近指数（V.I），和表面压力阈值（S.P.T.）。对于所有测试的酶，普遍的观察结果是，三种底物分化良好，并且在高界面能（低表面压）下分化更明显。这一观察结果支持了我们的假设，即脂肪酶的构象变化，导致从酶的表面相互作用，影响酶的特异性。一般来说，在甘油二酯和甘油三酯的情况下，甘油酯上sn-1或sn-3位置的立体参照都得以保持。(C)1995 Wiley-Liss，Inc.
Here we present a kinetic study on the steroselectivity and regioselectivity of 23 purified lipases of animal and microbial origin. This work, concerning a general problem of the mechanism of lipase-substrate molecular recognition, was performed using pure dicaprin isomers: 1,2-sn-dicaprin, 2,3-sn-dicaprin, and 1,3-sn-dicaprin spread as monomolecular films at the air-water interface. The first two isomers are optically active antipodes (enantiomers), forming stable films up to 40 mN m(-1), while the last is a prochiral compound, with a surface pressure of collapse of 32 mN m(-1). To our knowledge, this is the first report on the use of three diglyceride isomers as lipase substrates under identical and controlled physicochemical conditions. The lipases tested display a typical behaviour, characteristic of each enzyme, which allowed us to classify the lipases in groups according to (1) the profiles of enzyme velocity as a function of surface pressure, (2) their preferences for a given diglyceride isomer, quantified using new parameters termed steroselectivity index (S.L), vicinity index (V.I), and surface pressure threshold (S.P.T.). The general observation, true for all the enzymes tested, is that the three substrates are well differentiated, and the differentiation is more pronounced at high interfacial energy (low surface pressure). This observation supports our hypothesis that lipase conformational changes, resulting from the enzyme-surface interaction, affect the enzymes' specificities. Generally speaking, the stereopreference for either sn-1 or sn-3 position on glycerides is maintained both in the case of di- and tri-glycerides. (C) 1995 Wiley-Liss, Inc.