Werlen R C, Lankinen M, Rose K, Blakey D, Shuttleworth H, Melton R, Offord R E
Département de Biochimie Médicale, Centre Médical Universitaire, Geneva, Switzerland.
Bioconjug Chem. 1994 Sep-Oct;5(5):411-7. doi: 10.1021/bc00029a006.
A site-specific immunoconjugate was prepared between an F(ab')2-like fragment of the monoclonal anti-CEA murine IgG1 A5B7 and a mutant of the dimeric enzyme carboxypeptidase G2 possessing an N-terminal Thr in place of Ala. First an aldehyde was introduced at the N-terminus of the enzyme by mild periodate oxidation and a residue of carbohydrazide was specifically introduced at the C-terminus of the truncated heavy chain of the F(ab')2-like fragment by reverse proteolysis. Then the two modified proteins were conjugated by the formation of a hydrazone bond between the hydrazide and the aldehyde groups. The conjugate obtained retained both enzymic activity and antigen-binding capacity. The antigen-binding capacity was better than that of a similar conjugate made conventionally by random reaction with side chains.
