Changes in isoelectric points of the monoclonal antibody OC 125 during indium 111 radiolabeling
Legendre, J.M.; Bergot, A.; Turzo, A.; Morin, P.P.
Pathologie-Biologie 41(2): 169-171
1993
ISSN/ISBN: 0369-8114 PMID: 8327269 Document Number: 419773
Isoelectrofocusing analysis of the murine monoclonal antibody OC 125 (IgG1) revealed four bands at pI (6.6-7.2). After pepsin digestion, f(ab')2 pIs were increased by 0.6 pH units and two additional bands were visible. DTPA conjugation decreased pI (by up to -2 units) and increased heterogeneity (10 bands or more). With In3+ at saturation level, the conjugate was slightly modified. Autoradiography revealed pI heterogeneity of OC 125-f(ab')2-DTPA-In-111. These data show that isoelectrofocusing enables accurate monitoring of monoclonal antibody changes during In-111 labeling.