Immunoglobulins of colostrum. V. Comparative studies of ovine and bovine serum and colostral IgM.

Comparative studies of physiocochemical properties of ovine and bovine serum and colostral IgM are described. Serologic properties, molecular weight, amino acid composition, carbohydrate content, peptide maps, heterogeneity, and ORD and CD spectra were compared. Colostral IgM have additional antigenic determinants, higher carbohydrate content, lower heterogeneity, and higher content of beta-structure. Different amino acid composition and different peptide maps of serum and colostral IgM were shown. The results obtained suggest that ovine and bovine colostral IgM immunoglobulins may be a mixed population of molecules locally synthesized and transferred from the serum.