MULTIPLE FORMS OF EPIDERMAL ALPHA-FUCOSIDASE

Two forms of .alpha.-fucosidase from newborn rat epidermis were separated by gel filtration on Sephadex G-150. These enzymes were termed fucosidase I (eluted in the void volume) and fucosidase II (MW approximately 50,000). Both enzymes had pH optima for 4-methylumbelliferyl-.alpha.-L-fucoside hydrolysis between 5.5-6.5. Km values for fucosidase I and II with the same substrate were 3.7 .times. 10-5 and 5.4 .times. 10-5 M, respectively. Three different forms of newborn rat epidermal .alpha.-fucosidase were separated by isoelectric focusing. The electrophoretic heterogeneity of .alpha.-fucosidase is due in part to the binding of sialic acid to the primary gene product.