Adsorption of Immunoglobulin G on Core-Shell Latex Particles Precoated with Chaps

The aim of this work is to investigate the adsorption behavior of a monoclonal antibody (immunoglobulin G, IgG) on latex particles, possessing reactive chloromethyl groups, precoated with 3-([3-cholamidopropyl]dimethylammonio-1-propanesulfonate (Chaps). The amount and reactivity of the surface chloromethyl groups were monitored by the nucleophilic attack of glycinate to the functional groups as a function of time at 22 and 36 degrees C. The extent of displacement of Chaps by IgG and the enthalpy of the process were determined under two different conditions of precoating the latex particles with Chaps, at 22 and 36 degrees C. The adsorption of IgG takes place in two steps; the first one involves physical interaction between IgG and the surface. This step is relatively fast (in the range of minutes) and independent of temperature. In the second step covalent bonding between the protein and the active surface groups occurs. This reaction is improved by raising the temperature because Chaps desorption, which exposes the reactive chloromethyl groups on the latex particles, is kinetically and thermodynamically favored at 36 degrees C and the covalent bonding of IgG is faster at 36 degrees C. Copyright 2000 Academic Press.