The Effect of Acid, Pepsin and Trypsin on Human Colostral IgA Agglutinins

Abstract
Secretory IgA prepared from pooled human colostrum has been shown to agglutinate a wide range of aerobic intestinal bacteria. The effects of acid (pH 2.5), pepsin and trypsin on secretory IgA antibody have been studied by gel filtration, Immunoelectrophoresis, and by effect on agglutinin titres. Trypsin produced no detectable changes. Acid produced a small fall in agglutinin titres. Peptic digestion at pH 2.5 produced a rapid fall in agglutinin titre, accompanied by the appearance of changes in the immunoelectrophoretic are, and the appearance of lower molecular weight components on gel filtration.