Kinetics of interaction between 3-hydroxyphthaloyl-β-lactoglobulin and CD4 molecules

Kinetics of 3-hydroxyphthaloyl-β-lactoglobulin-CD4 interaction were evaluated using a biosensor instrument based on surface plasmon resonance. A very fast association (k(a) = 2.4 ± 0.3 x 106 M-1 s-1) and slow dissociation (K(d) = 2.3 ± 0.14 x 10-4 s-1) rate constants were observed indicating the high affinity of the complex. This result together with earlier data, suggest that 'structure-specific' requirements must be met to endow acid anhydride modified lactoglobulin with the capacity for high affinity binding to CD4.