Site-specific conjugation of an enzyme and an antibody fragment.
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.
Département de Biochimie Médicale, Centre Médical Universitaire, Geneva, Switzerland.
R C
RC
Werlen
M
M
Lankinen
K
K
Rose
D
D
Blakey
H
H
Shuttleworth
R
R
Melton
R E
RE
Offord
D000911:Antibodies, Monoclonal / Q000737:chemistry*; D000912:Antibodies, Neoplasm / Q000737:chemistry*; D000937:Antigen-Antibody Reactions; D002272:Carcinoembryonic Antigen / Q000276:immunology; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D006835:Hydrazones / Q000737:chemistry; D006868:Hydrolysis; D018796:Immunoconjugates / Q000737:chemistry*; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry* / Q000276:immunology; D013058:Mass Spectrometry; D009154:Mutation; D010084:Oxidation-Reduction; D011355:Prodrugs; D011623:gamma-Glutamyl Hydrolase / Q000737:chemistry / Q000235:genetics
D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D002272:Carcinoembryonic Antigen; D006835:Hydrazones; D018796:Immunoconjugates; D007140:Immunoglobulin Fab Fragments; D011355:Prodrugs; D011623:gamma-Glutamyl Hydrolase