Abstract
1. The enzyme preparations derived from pig and human livers, acting on human blood group A substance and A red cells, destroyed their A activities with enhancement of O (H) activities. In these cases, these enzyme preparations showedtoliberate N-acetylgalactosamine, determinant of A specificity, from them. From these results, A-decomposing enzymes presented here were considered to be consisted of α-N-acetylgalact osam inidase.
2. After the complete destruction of A activity in A substance by pig and human liver enzymes, about 20% of the original quantities of N-acetylgalactosamine were liberated by the former and about 16% by the latter. N-Acetylglucosamine, galactose and small amounts of fucose were also shown to be liberated by both enzymes.
3. These enzyme preparations contained, besides α-N-acetylgalactosaminidase, α-and β-glucosidases (β-glucosidase was weak in the enzyme preparation from human liver.), α-and β-galactosidases, α-andβ-mannosidases, α-L-fucosidase, β-N-acetylglucosami nidaseand β-N-acetylgalactosaminidase.
However, these enzyme preparations destroyed hardly B activity in B substance and O (H) activity in O (H) substance.
