Immunoglobulins of sheep

Immunoelectrophoretic analysis of fractions obtained by DEAE-Sephadex ion exchange chromatography suggests that ovine immunoglobulins may comprise at least five distinct classes. In addition to the electrophoretically slow γ2 and fast γ1 immunoglobulin G, there exists another closely related immunoglobulin which may be either another immunoglobulin G or an analog of human immunoglobulin D. Immunoglobulin M and a fraction containing mainly immunoglobulin A have also been prepared. Antibody activity against dinitrophenyl-bovine serum albumin and a heteropolymer composed of glutamic acid, alanine, and tyrosine was found in the slow and fast immunoglobulin G fractions. The slow and the fast immunoglobulin G preparations were also degraded by papain. Analyses made on the recovered breakdown products suggest their close resemblance to similarly prepared fragments of immunoglobulin of man, rabbit, and other mammals.