Alpha-L-fucosidase from a soil bacterium.

Intracellular glycosidases were measured in cell-free extracts obtained by ultrasonic disruption of a gram-negative soil coccobacillus (Chase, 1938). From these extracts, alpha-l-fucosidase was purified about 120-fold by salting out with (NH(4))(2)SO(4), ion exchange chromatography, and gel filtration. The approximate molecular weight of the enzyme was 50,000; its pH optimum was 5. The enzyme was inhibited by l-fucose and split this sugar from a purified acid mucopolysaccharide from chicken chorioallantoic fluid. The acid mucopolysaccharide is identical with a component (host antigen) of the hemagglutinin of influenza virus. Its antigenic reactivity is altered by cell-free extracts of the bacterium, in which the responsible enzyme is thought to be an alpha-l-fucosidase.