Serological studies on the carbohydrate moiety of human tyrosinase.

1. Human tyrosinase is a glycoprotein containing N-acetylneuraminic acid. 2. The terminal neuraminic acid groups are linked to D-galactose. 3. In addition, human tyrosinase reacts strongly with concanavalin A. This finding indicates that the carbohydrate chain of human tyrosinase contains D-mannose. 4. The data presented here suggest that the carbohydrate moiety of human tyrosinase is linked to the protein core in an alkali-stable form. 5. Alkali-labile carbohydrate chains which occur predominantly in membrane bound glycoproteins could not be demonstrated serologically.