Kinetics and interaction constants of protein adsorption onto mineral microparticles - measurement of the constants at the onset of hysteresis

The kinetics of desorption of human serum albumin from silica and talc microparticles are presented. The evolution of hysteresis, i.e. of the progressive bond strengthening between protein molecules and solid substratum, was monitored by calculating the Langmuir adsorption isotherms, as well as the desorption rates and desorbable protein amounts after various particle-protein contact times. The effect of parameters such as temperature, ionic strength, presence of cation-complexing and protein denaturation agents, on the desorption rate and maximum desorbable amount were also examined. The results help elucidate the mechanism of protein adsorption and also the strength of the formed bonds before and after the onset of hysteresis. (C) 2001 Elsevier Science B.V. All rights reserved.