MONITORING CATALYTIC ACTIVITY BY IMMUNOASSAY - IMPLICATIONS FOR SCREENING

We have developed an immunoassay for screening large libraries of pote ntial catalysts of a bimolecular Diels-Alder reaction. The procedure i nvolves the reaction of immobilized dienophile with diene in solution and subsequent detection of the product with a monoclonal antibody as in a regular enzyme-linked immunosorbant assay (ELISA). The assay exhi bits the expected dependence on time and diene concentration. A cataly tic antibody accelerates the reaction in a concentration dependent man ner despite immobilization of the dienophile, and its catalytic effici ency is comparable to that in free solution. The current study explore s both the utility of this assay and criteria for its successful appli cation to other reactions. Employment of this strategy, previously dub bed catELISA (Tawfik, et al. PNAS 1993, 90, 373), to monitor a bimolec ular cycloaddition reaction supports its potential as a general approa ch to screening for catalysts.