Immunochemical studies on non-precipitating guinea pig antibody produced by administration of an excessive dose of Bacillus subtilis alpha-amylase.
Administration of an excessive dose of Bacillus subtilis alpha-amylase [EC 3.2.1.1, alpha-1,4-glucan 4-glucanohydrolase] (BalphaA) induced the production of non-precipitating (non-ppt) IgG2 antibody in guinea pigs, whereas immunization with a normal dose produced precipitating (ppt) IgG1 and IgG2 antibodies. The non-ppt IgG2 antibody thus produced could be isolated from the coexisting ppt IgG2 antibody by means of the precipitin reaction at maximum precipitation. The non-ppt antibody was incapable of forming a precipitin arc with BalphaA in a conventional agar plate. In the presence of 4% polyethylene glycol (PEG), however, it formed a single arc which fused completely with those of the ppt IgG1 and IgG2 antibodies. The non-ppt antibody could not fix complement, but inhibited BalphaA activity, though with less efficiency than the ppt antibodies. These properties of the non-ppt IgG2 antibody may be due to a low affinity for BalphaA, since both gel filtration and precipitation of soluble antigen-antibody complexes with 20% PEG showed that the antibody was easily dissociable from BalphaA.
D000681:Amylases / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D000917:Antibody Formation; D000936:Antigen-Antibody Complex; D001412:Bacillus subtilis / Q000201:enzymology*; D001666:Binding Sites, Antibody; D004306:Dose-Response Relationship, Immunologic; D006168:Guinea Pigs; D007074:Immunoglobulin G / Q000096:biosynthesis*; D011092:Polyethylene Glycols; D011233:Precipitin Tests
D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D011092:Polyethylene Glycols; D000681:Amylases