KINETICS OF EXCHANGE PROCESSES IN THE ADSORPTION OF PROTEINS ON SOLID-SURFACES

The homogeneous exchange process whereby IgG molecules adsorbed onto l atex particles are replaced by IgG molecules from the bulk solution wa s studied by means of 125I radiolabeling. The exchange mechanism was i nvestigated on surfaces saturated with either labeled or unlabeled pro teins in the presence of a solution of the opposite species in two set s of independent experiments. After rinsing of the surface by pure buf fer followed by supplementary IgG adsorption, the exchange process fol lowed a kinetic law of first order with respect to the IgG molecules f rom the bulk solution, and the apparent exchange rate constant was (2. 3 +/- 0.4) x 10(-5) cm.hr(-1).