Creation of a ribonuclease abzyme through site-directed mutagenesis

The development of abzymes (antibody/enzymes) is one method of creating reagents with novel catalytic activity. To date, most abzymes have been obtained by immunization with transition state analogs. We have chosen to start with an existing antibody and convert it into an enzyme by the addition of catalytic residues to the binding site. We have introduced a histidine residue into antibody Jel 103 and converted it into an abzyme that cleaves poly(rI) with a kinetic efficiency of about 100 M(-1) sec(-1).