title: Heterogeneity of phenol oxidases in Cryptococcus neoformans.
abstract: Phenol oxidase enzymes, linked to virulence in Cryptococcus neoformans, were prepared from broken cells. More enzyme activity was found in the ultracentrifugation supernatant; less was found in the membrane fraction. Phenol oxidases were located in acrylamide gel electropherograms by activity staining with L-dihydroxyphenylalanine (DOPA). Mobility differences between soluble and solubilized membrane-bound phenol oxidases were not found. Comparison of enzymes produced at 25 and 37 degrees C revealed that the enzyme had lower activity and lower mobility at 37 degrees C. The mobility of 25 degrees C phenol oxidases from strains of C. neoformans var. gattii was lower than that of those from C. neoformans var. neoformans. Half of the phenol oxidase produced at 25 degrees C was bound by concanavalin A, while that produced at 37 degrees C was not bound. However, glucose starvation of cultures at 25 degrees C overnight resulted in increased amounts of enzyme which did not bind to concanavalin A. A given strain of C. neoformans produces different species of phenol oxidase under different culture conditions.
authors.affiliation: Research Service, McGuire Veterans Affairs Medical Center, Richmond, Virginia 23249.
authors.forename: R
authors.initials: R
authors.lastname: Ikeda
authors.forename: E S
authors.initials: ES
authors.lastname: Jacobson
mesh_terms: D003455:Cryptococcus neoformans / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D014442:Monophenol Monooxygenase / Q000032:analysis*; D013696:Temperature
chemical_list: D014442:Monophenol Monooxygenase