ADSORFHON OF HUMAN IgG MOLECULES ONTO GLASS BEADS: REVERSIBLE AND IRREVERSIBLE ASPECTS

ABSTRACT

Reversible and irreversible aspects of polyclonal IgG adsorption onto glass beads were studied using ¹²⁵I radiolabeled proteins for bulk concentrations as low as 4× 10⁻⁴ mg ml⁻¹. A true thermodynamic equilibrium was reached in the low bulk concentration domain, and a saturation of 0.1μg cm⁻² was noticed for concentrations ranging from 0.03 to 0.37mg ml⁻¹. The decrease of the amount of desorbed IgG's with increasing bulk concentrations in the plateau domain taken together with the impossibility to adjust desorption kinetics using a single exponential law, allowed us to propose an adsorption mechanism in which two protein populations i.e. rapidly (state B) and slowly (state C) desorbed molecules are involved