作者:Robert Kourist、Yusuke Miyauchi、Daisuke Uemura、Kenji Miyamoto
DOI:10.1002/chem.201001924
日期:2011.1.10
Variant G74C of arylmalonate decarboxylase (AMDase) from Bordatella bronchoseptica has a unique racemising activity towards profens. By protein engineering, variant G74C/V43A with a 20‐fold shift towards promiscuous racemisation was obtained, based on a reduced activity in the decarboxylation reaction and a two‐fold increase in the racemisation activity. The mutant showed an extended substrate range
支气管败血波氏杆菌中的芳基丙二酸脱羧酶(AMDase)G74C变体对profens具有独特的消旋作用。通过蛋白质工程,基于脱羧反应的活性降低和消旋活性的两倍提高,获得了向混杂消旋化20倍的变体G74C / V43A。该突变体显示出扩大的底物范围,对酮洛芬的反应速率提高了30倍。分子动力学模拟和消旋酶的底物特征表明,底物结构的空间和极性效应在催化方面比单纯的动力学α-质子酸度起着更大的作用。β,γ-不饱和羧酸的转化不会导致重排形成其α,β异构体的观察结果表明,这是一个协调的机制,而不是逐步的机制。有趣的是,