title: The secretion of N-acetylglucosaminidase during germ-tube formation in Candida albicans.
abstract: N-Acetylglucosaminidase was induced by either N-acetylglucosamine or N-acetylmannosamine in several strains of Candida albicans. Enzyme activity was not induced in a N-acetylglucosamine non-utilizing mutant which is unable to express the first three steps in the N-acetylglucosamine catabolic pathway. The enzyme, purified 500-fold, had a specific activity of 36.8 units (mg protein)-1 and catalysed the hydrolysis of p-nitrophenyl-beta-n-acetylglucosamine, N,N'-diacetylchitobiose and N,N',N"-triacetylchitotriose. No activity was observed toward colloidal chitin, hyaluronic acid or mucin. The cellular distribution of N-acetylglucosaminidase was determined by measuring in situ enzyme activity before and after acid treatment of intact cells. N-Acetylglucosaminidase (80-88% of the total cellular activity) was rapidly secreted to the periplasm when the enzyme was induced either during yeast growth at 28 degrees C or germ-tube formation at 37 degrees C. Export of the enzyme from the periplasm into the medium was fourfold greater during germ-tube formation, and after 6 h incubation the amount of enzyme released into the medium represented 70% of cell-associated enzyme activity.
mesh_terms: D000117:Acetylglucosamine / Q000494:pharmacology; D000118:Acetylglucosaminidase / Q000096:biosynthesis* / Q000302:isolation & purification; D002176:Candida albicans / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D004790:Enzyme Induction / Q000187:drug effects; D006595:Hexosamines / Q000494:pharmacology; D006596:Hexosaminidases / Q000096:biosynthesis*; D013379:Substrate Specificity
chemical_list: D006595:Hexosamines; D006596:Hexosaminidases; D000118:Acetylglucosaminidase; D000117:Acetylglucosamine; C002022:N-acetylmannosamine