SIMILARITIES OF HYDROLYTIC ANTIBODIES REVEALED BY THEIR X-RAY STRUCTURES - A REVIEW

Numerous antibodies have been programmed to catalyse the hydrolysis of esters as well as other acyl transfer reactions. They were raised aga inst stable analogues that model the structure of the tetrahedral tran sition states of these reactions. The three-dimensional structures of four hydrolytic antibodies complexed to their respective phosphonate t ransition state analogues (TSAs) reveal a similar orientation of hapte n relative to the antibody. Analysis of the four combining sites sugge sts that residues binding the phosphonate TSA stabilise the oxyanion i ntermediate of the reaction and play a preponderant role in catalysis. Comparison of catalytic antibodies selected from the same hybridoma f usion indicates a high similarity of the motifs that catalyse the hydr olysis of a given substrate.