Kinetic and immunochemical characterization of α-l-fucosidase from vertebrate livers

1. 1. Crude liver α- l -fucosidase was investigated in 10 vertebrate species ranging from fish to human using 4-methylumbelliferyl-α- l -fucopyranoside as substrate. 2. 2. The α- l -fucosidases were characterized by determinations of pH optima and isoelectric focusing profiles, K m values, thermostabilities after preincubation at 45°C and 60°C, and immunoprecipitation by anti-human liver α- l -fucosidase antibody. 3. 3. Results suggest differences in liver α- l -fucosidases with respect to pH optima, thermostabilities and isoelectric focusing profiles. However, the K m values were largely similar and 9 to 10 species were precipitated by the human IgG preparation, suggesting antigenic similarity.