Effects of chemical modification of carboxyl groups in the hemolytic lectin CEL-III on its hemolytic and carbohydrate-binding activities

Effects of chemical modification of carboxyl groups in the hemolytic lectin GEL-III on its activities were investigated. When carboxyl groups were mod ified with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and glycine methyl ester, hemolytic activity of GEL-III decreased as the EDC concentrat ion increased, accompanied by reduction of oligomerization ability and hema gglutinating activity. However, binding ability of GEL-III for immobilized lactose was retained fairly well after modification, suggesting that one of two carbohydrate-binding sites might be responsible for such inactivation of GEL-III.