Construction of phosphorylatable monoclonal antibody to a tumor-associated antigen
Lin, L.; Daugherty, B.; Schlom, J.; Pestka, S.
Cancer Research 56(18): 4250-4254
1996
ISSN/ISBN: 0008-5472 PMID: 8797600 Document Number: 467046
A phosphorylation site was introduced into chimeric monoclonal antibody B72.3 (MAb-chB72.3) by site-specific mutation of the coding sequence. The phosphorylation site for the cAMP-dependent protein kinase was positioned at the carboxyl terminus of the heavy-chain constant region of MAb-chB72.3. The resultant modified MAb-chB72.3-P was expressed in 293 cells and purified. The MAb-chB72.3-P protein was phosphorylated by the catalytic subunit of cAMP-dependent protein kinase with (gamma-32P)ATP to high radiospecific activity. The 32P-labeled MAb-chB72.3-P protein bound to cells expressing the tumor-associated glycoprotein 72 antigen. The introduction of phosphorylation sites into MAbs provides a new type of MAb for the diagnosis and treatment of cancers.