An Enzyme Decomposing Common Antigenic Substance between Blood Group Substance and Diplococcus pneumoniae Type XIV. I

Abstract

1. A strain of Clostridium tertium was isolated from the soil which produced an enzyme acting on O(H) substance and group O red cells. The enzyme abolished not only their O(H) activity but also cross-reactivity with anti-pneumococci Type XIV chicken serum. The enzyme preparation decomposed O(H) substance, converting it into a substance which contained D-galactosamine and (or) D-glucosamine as antigenic determinant. This enzyme preparation also decomposed Lea substance. In addition to this enzyme, the strain produced A-decomposing enzyme. 2. These enzymes were found in a fraction which precipitated at 40-50% ammonium sulfate saturation of culture filtrate of the strain. By means of DEAE cellulose column chromatography, the enzyme decomposing O(H) and Lea could be separated from the A-decomposing enzyme. For both of them, the optimal pH ranged 6.3-7.2, and the optimal temperature 30°-37°C. 3. The actions of these enzymes were inhibited by such metal salts as mercuric chloride and copper sulfate. The enzymic action to decompose O(H) substance reacting with anti-O(H) antibody in eel serum was inhibited strongly by L-fucose, and slightly by lactose and D-galactose. The enzymic action to decompose O(H) substance reacting with anti-O(H) antibody in anti-Sh. dysenteriae chicken serum was inhibited strongly by lactose, D-galactose, and other sugars containing galactose, and weakly by L-fucose. And the enzymic action to decompose O(H) substance reacting with antibody in anti-pneumococci Type XIV chicken serum was inhibited by lactose, D-galactose, and N-acetyl-D-glucosamine. The Lea-decomposing action was inhibited strongly by L-fucose and D-galactose, and weakly by N-acetyl-D-glucosamine and N-acetyl-D-galactosamine. And the action of the A-decomposing enzyme was inhibited most strongly by N-acetyl-D-galactosamine, and also by lactose, D-galactose, and N-acetyl-D-glucosamine.