Effect of Molecular Weight on Uptake of Antigens by Immunologic Aggregates

[摘要] Washed specific precipitates were prepared from goat antiserum to rabbit γ-globulin and rabbit antibody to a series of protein antigens. The ability of these aggregates to bind antigen specifically was studied with I131-labeled materials.It was found that aggregates prepared with rabbit antibody to ribonuclease, hen egg albumin, bovine serum albumin and human γ-globulin could, with sufficiently long incubation, take up approximately 80% of theoretic amounts of antigen. Aggregates prepared with rabbit antibody to hog thyroglobulin and busycon hemocyanin bound only small amounts of antigen.The results suggest that the dimension of the lattice formed by goat antibody and rabbit γ-globulin permit antigens up to the size of human γ-globulin to enter and react with specific rabbit antibody sites. The larger antigens are almost totally excluded and react probably only at the surface of the aggregate. Each molecule of rabbit antibody is positioned in the aggregate so as to be capable of binding close to two molecules of antigen under optimal conditions.

[学科分类] 生物科学（综合）