作者:Roman Manetsch、Lei Zheng、Martine T. Reymond、Wolf-Dietrich Woggon、Jean-Louis Reymond
DOI:10.1002/chem.200305629
日期:2004.5.17
ammonium cation 5 and its guanidinium analogue 4 are inhibitors of tocopherol cyclase. Monoclonal antibodies were raised against protein conjugates of the haptens 1-3 and screened for catalytic reactions with alkene 8, a short chain analogue of the natural substrate phytyl-hydroquinone 6, and its enol ether analogues 10a,b. Antibody 16E7 raised against hapten 3 was found to catalyze the hydrolysis of Z
环状铵阳离子5及其胍类似物4是生育酚环化酶的抑制剂。产生针对半抗原1-3的蛋白质缀合物的单克隆抗体,并筛选与烯烃8,天然底物植酸氢醌6的短链类似物及其烯醇醚类似物10a,b的催化反应。发现针对半抗原3的抗体16E7催化Z烯醇醚10a的水解以形成半缩醛12,表观速率加速为k(cat)/ k(uncat)= 1400。抗体16E7还催化消除肯普氏苯并异恶唑59。烯醇醚10a反应中没有环化作用是由于水分子竞争抗体结合口袋中的氧碳鎓阳离子中间体。讨论了有助于此结果的半抗原和反应设计特征。如第一原理所预期的,抗体16E7提供了羧基的第一实例,该羧基既在本征酸催化的过程中充当酸,又在本征碱催化的过程中充当碱。与已知由催化抗体催化的一般酸催化方法的许多例子相反,植酸氢醌6或其类似物8的特异性酸催化环化仍然没有抗体催化。