Measurement of kinetic binding constants of a panel of anti-saporin antibodies using a resonant mirror biosensor.
We have used a resonant mirror biosensor to determine the kinetics of binding of four antibodies, and their Fab' fragments, to their antigen, the plant-derived ribosome-inactivating protein (RIP) saporin. The analysis of the affinity of the antibodies was in reasonable agreement with values obtained by conventional techniques. However, the kinetic data showed that all four antibodies have a high dissociation rate constant (kdiss). These antibodies have been used in the construction of bispecific antibodies used to deliver saporin to tumour cells, and it is highly probable that the in vivo efficacy of the bispecific antibodies is limited by the high rate of dissociation of antibody-toxin complexes.
George
A J
AJ
Department of Immunology, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
French
R R
RR
Glennie
M J
MJ
D000486:Allergy and Immunology / Q000295:instrumentation; D000818:Animals; D018033:Antibodies, Bispecific / Q000276:immunology / Q000378:metabolism*; D000915:Antibody Affinity / Q000276:immunology*; D015374:Biosensing Techniques; D007140:Immunoglobulin Fab Fragments / Q000276:immunology / Q000378:metabolism; D000922:Immunotoxins / Q000276:immunology; D007700:Kinetics; D051379:Mice; D015336:Molecular Probe Techniques / Q000295:instrumentation*; D009699:N-Glycosyl Hydrolases; D010940:Plant Proteins / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding / Q000276:immunology; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins
D018033:Antibodies, Bispecific; D007140:Immunoglobulin Fab Fragments; D000922:Immunotoxins; D010940:Plant Proteins; D054789:Ribosome Inactivating Proteins, Type 1; D009699:N-Glycosyl Hydrolases; D000076985:Saporins