Selection of monoclonal antibodies for linear epitopes of an apolipoprotein yields antibodies with comparable affinity for lipid-free and lipid-associated apolipoprotein

A direct approach is described for generating human apolipoprotein (apo) A-I-specific monoclonal antibodies with defined linear epitopes. The antibodies have comparable binding affinity for delipidated apoA-I and apoA-I on high density lipoproteins (HDL). The antibodies were obtained by immunizing mice with HDL, screening the fusions first for antibodies that bind native HDL and second, for antibodies that bind defined apoA-I synthetic peptides. ApoA-I antibody epitopes assigned on the basis of synthetic peptide binding were confirmed by solid phase and fluid phase antibody competition assays. These antibodies, which bind epitopes that encompass greater than 60% of apoA-I, should prove useful for identifying discrete functional domains of apoA-I on HDL.