Antibody-Catalyzed Hydrolysis of Enol Ethers. 2. Structure of the Antibody-Transition State Complex and Origin of the Enantioselectivity
作者:Guiti K. Jahangiri、Jean-Louis Reymond
DOI:10.1021/ja00104a008
日期:1994.12
transition state relative to the hapten is then established by comparing the effect of alkyl substitutions at the /?-carbon on antibody catalysis with the effect of equivalent substitutions on antibody binding to hapten analogs. For antibody 14D9 (anti-1), the results show that the alkyl substituent of the enol ether's /?-carbon binds to the N-methyl site of the hapten at the transition state. Substitution
烷基烯醇醚水解为其相应的羰基化合物,是通过酸催化对 β-碳进行定速质子化,形成氧碳离子中间体 (Kresge, AJ; Chang, YJ Chem. SOC. B 1967, 53) . 抗体 14D9 (anti-1) 以非常高的质子化对映选择性催化烯醇醚 4 和 5 的水解(Reymond, J.-L.; Janda, KD; Lerner, RAJ Am. Chem. SOC. 1992, 114, 2257) . 催化包括抗体侧链作为一般酸的参与,以及烯醇醚 c Jahangiri, GK 的锥体化;斯托德,C.;勒纳,RAJ Am。化学 SOC。1993、115、3909)。本研究解决了该催化剂对映选择性起源的问题。首先,对映选择性和底物耐受性,这在抗体 14D9 中最为显着,显示为抗 1 或抗 2 抗体的复发特征。研究了四种抗体,所有抗体都对映选择性地在烯醇醚的背面传递质子以产生