Evolving catalytic antibodies in a phage-displayed combinatorial library.

In vitro affinity maturation for evolving catalytic antibodies has been demonstrated by generating a diverse repertoire of the appropriate complementarity-determining regions on a phage surface. Phage display is followed by a selection based on binding to an altered antigen that was not used at the time of immunization, and provides variants with new catalytic activity and substrate specificity. This library format reduces the time needed to isolate the desired catalytic antibody fragments to under 2 weeks.