Antibody catalysis of pericyclic reactions.

In an effort to increase our insight into the catalysis of pericyclic reactions we have initiated a detailed study of an antibody that catalyzes an oxy-Cope rearrangement. We have determined the stereochemistry of the antibody-catalyzed reaction, and experiments are in progress to determine the conformation of the substrate bound in the antibody combining site. The genes encoding the variable regions of this antibody have been cloned and sequenced, and we have made use of a bacterial expression system to produce this antibody as a Fab fragment in recombinant form, making it amenable to genetic manipulations such as site-directed mutagenesis. The recombinant Fab fragment has been crystallized in the presence of its transition state analog, and we are now in the process of determining its active site structure.