THE ACTION OF ENZYMES FROM CLOSTRIDIUM TERTIUM ON THE I ANTIGENIC DETERMINANT OF HUMAN ERYTHROCYTES.

A method was described for the partial purification of beta galactosidase and beta glucosaminidase from Clostridium tertium culture supernatants. Treatment of erythrocytes with preparations containing both enzymes decreases their ability to react with anti-I cold agglutinins, and with Type XIV antipneumococcal horse serum. Erythrocytes of blood group A(1) are altered more rapidly and extensively than are group O cells. The enzymatic treatment of stroma results in a decrease in ability to absorb anti-I agglutinins and the release of galactose and N-acetylglucosamine as monosaccharides. The data suggest that these two sugars may be structural units of the erythrocyte I determinant, but no direct evidence is available.