In the field of carbohydrate chemistry, differentiation of the potentially competing functions is rather formidable. For example, the extension of an oligosaccharide at a single glucose entity requires the identification of one of five hydroxyls to function as glycosyl acceptor. Chemists carry out multi-step protection-deprotection processes by the combination of many protective groups, such as esters, ethers, carbonates, ketals etc., to resolve this problem. Generation of a catalytic antibody which recognizes and catalyzes the hydrolysis of certain ester bond as programmed by the hapten might simplify oligosacchride synthesis. We designed and synthesized hapten-KLH conjugate 5 to generate monoclonal antibodies that catalyze selective hydrolysis of the 4-positioned ester of glucose derivatives. The immunization elicited fourteen IgG which bound to the hapten portion. Two IgG were found to catalyze the hydrolysis reaction of the substrate 17 at the directed 4-position selectively with significant rate enhancement compared to the uncatalyzed background reaction. One antibody (17E11) was further characterized in detail.
