Action of Enzymes from Clostridium tertium A on the Group A Antigenic Determinant of Human Erythrocytes
It is well known that Clostridium tertium A produces Adecomposing enzymes. We investigated the changes in ABO-antigenicity of human erythrocytes caused by the culture filtrate from this bacteria. Group A erythrocytes were specifically affected, and a decrease in A-activity and an enhancement of H-activity were observed. No change was observed on group B and O cells. There was a significant difference between the agglutinabilities of group A1 and A2 erythrocytes treated with Cl. tertium culture filtrate. A2 erythrocytes completely lost their agglutinability against undiluted anti-A sera. In contrast, A1 erythrocytes preserved a low Aantigenicity. It was clear that this difference reflected the heterogenous nature of A-antigenicity on group A cell membranes. On the other hand, it was suggested that the A-decomposing enzymes in the culture filtrate also had a heterogenous nature. Our crude enzyme preparation was completely inhibited by D-galactosamine, and weakly by N-acetyl-Dgalactosamine or D-galactose. Further enzyme purification was required to elucidate the differences in the antigenic determinants or the structural basis between A1 and A2 erythrocytes.
