Direct Demonstration and Quantitation of Aal, Aa2 and Aa3 Allotypic Specificities on Fd-Fragments of Rabbit Immunoglobulin G

[摘要] 1. 1. Fd-fragments were prepared from Fab-fragments obtained by papain digestion of rabbit immunoglobulin-G (IgG). In addition, a 5 S piece was obtained by cyanogen bromide treatment of IgG and an Fd derived from the 5 S piece was prepared.2. 2. Polyalanylation was carried out in order to solubilize the Fd-fragments. Some masking of a -locus-allotypic specificity was demonstrated when IgG and 5 S piece were polyalanylated.3. 3. 125I-labeled fragments were allowed to react with either anti-a1, -a2 or -a3 antisera and supernatant portions were precipitated with appropriate anti-allotype antisera specific only for the antibody portion of the soluble complexes. In spite of some probable masking due to polyalanylation, the majority of polyalanylated Fdfragments (generally more than 60%) had demonstrable determinants associated with a -locus-allotypic specificity.4. 4. Fab-fragment (a2), from which noncovalently linked glycopeptides were removed on Sephadex in 1 M propionic acid, retained a2 allotypic specificity.5. 5. Fd-fragments derived from CNBr treated IgG, especially those with short polyalanine chains, gave high control values with normal rabbit sera, suggesting either a nonspecific or a specific affinity for immunoglobulins in normal rabbit sera.

[学科分类] 生物科学（综合）