Low molecular weight protein in bovine anterior pituitary similar to immunoglobulin M

Bovine pituitary IgM was isolated from anterior lobe material by molecular sieve and DEAE-cellulose chromatography. It was characterized using physico-chemical and immunochemical techniques. The molecular weight of the molecule was below 20 000, and immunoelectrophoretic and immunodiffusion analysis, demonstrated precipitin arcs for IgM. The small molecular weight protein may prove to be significant in continuing studies of IgM and the relationship of the pituitary gland to the immune system.