AFFINITY PURIFICATION OF POLYCLONAL ANTIBODIES USING IMMOBILIZED MULTIMERIC PEPTIDES

The possibility of using multiple antigenic peptides (MAP) not only fo r the production and characterisation of antibodies but also for their purification by affinity chromatography, has been explored with two d ifferent tetrameric MAPs synthesised starting from a tetradentate lysi ne core. Recognition selectivity and specificity of the multimeric ant igens were retained after immobilization on preactivated affinity supp orts, allowing convenient antibody purification directly from crude se ra in a single chromatographic step. Since antibodies raised against M APs recognise very frequently the N-terminal portion of the peptide an tigen, results suggest that only a limited number of peptide chains re mains covalently linked to the solid phase, leaving the others uncoupl ed and free to interact fully with the antibody. Recovery of antibody immunoreactivity from affinity purifications on MAP-columns was much h igher than that obtained from columns prepared by immobilizing at the same density the corresponding linear peptide antigen. The purity of t hus obtained antibodies is also far superior, as detected by SDS-PAGE analysis. Retention of the multimeric peptide recognition properties f or the corresponding antibodies after immobilization on solid supports suggests that production, characterization, and even the affinity pur ification of anti-peptide antibodies, could be carried out simply and conveniently via the synthesis of a single multimeric antigen, without additional steps.