Are 'new' antigenic determinants exposed on aggregated bovine serum albumin?

Antigenic specificities of native monomer, heat-denatured monomer and heat-polymerized BSA have been compared serologically. Distinct differences between monomer and polymer preparations were observed with respect to their ability to inhibit each other's binding to antibody and also between their respective rates of dissociation from immune complexes. While it would be possible to interpret the results in terms of the appearance of 'new' antigenic determinants on the polymerized antigen, the results are best explained by an enhanced capacity of polymerized BSA to establish polyvalent binding to antibody of low intrinsic affinity.