Abstract
Fab (3·5 S) fragments were derived from IgG fractions of anti-dinitrophenyl and anti-lysergil antisera by papain digestion to reduce avidity forces due to polyvalency. The Fab fractions were immunoadsorbed to obtain active purified fragments. Ligand binding properties of the purified Fab fragments were measured by equilibrium dialysis and were compared to the properties of the original unadsorbed fractions. Purified Fab fragments possessed higher average intrinsic association constants ( K o) than intact IgG antibodies from which they were derived. Purified anti-dinitrophenyl Fab fragments exhibited a K o of 3·5 × 10 6 M −1 compared to 8·7 × 10 5 M −1 for the unadsorbed Fab and IgG fractions. Anti-lysergyl Fab fragments exhibited a K o of 1·7 × 10 6 M −1 compared to 1·4 × 10 5 M −1 for its unadsorbed Fab and IgG fractions. It is propsed that this increase in K o for the adsorbed Fab fragments is a result of the loss of avidity or functional affinity.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
