The proposed research is aimed at the purification and characterization of endoglycosidases through the use of well-defined carbohydrate substrates procured mainly by chemical synthesis. Some structures needed may also be prepared through enzyme catalysis with a glycosyltransferase and appropriate acceptors. Two enzymes will be emphasized: a) endo-alpha-N-acetyl-D-galactosaminidase from Clostridium perfringens and Streptococcus pneumoniae, and 2) endogalactosaminidase from Streptomyces griseus. The selected endoglycosidases with well-defined specificity will become important tools for structural studies in the carbohydrate portions of O-glycosidically linked glycoproteins. These enzymes are likely to have important applications in demonstrating the role of carbohydrate chains in naturally occuring antigens.
