Partial purification and properties of a beta-N-acetylglucosaminidase from the fungus Sclerotinia fructigena.
1. As cultures of the fungus Sclerotinia fructigena autolysed, the filtrates contained increasing quantities of a beta-N-acetylglucosaminidase. 2. The enzyme was purified up to 42-fold by a combination of isoelectric focusing and gel filtration. 3. It ran as a single band in cellulose acetate strip electrophoresis and in isoelectric focusing (pI3.76). 4. The enzyme did not readily hydrolyse chitin or a glycopeptide with terminal N-acetylglucosamine residues, but rapidly degraded the N-acetylglucosamine dimer NN'-diacetylchitobiose; the monomer was readily utilized by the fungus as a nitrogen source. The K(m) value for hydrolysis of p-nitrophenyl beta-2-acetamido-2-deoxy-d-glucopyranoside at 37 degrees C was 2.0mm. The Sclerotinia enzyme was generally less susceptible to inhibition by 2-acetamido-2-deoxygluconolactone and other related sugars than the corresponding enzyme from other sources. Inhibition by excess of substrate was observed. 5. The culture filtrate also contained N-acetylgalactosaminidase activity; conflicting evidence was obtained as to whether the same enzyme was responsible for both hexosaminidase activities.
D000081:Acetamides; D000135:Acid Phosphatase / Q000378:metabolism; D001203:Ascomycota / Q000166:cytology / Q000201:enzymology*; D002473:Cell Wall / Q000201:enzymology; D002688:Chitinases / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D002854:Chromatography, Paper; D003470:Culture Media; D004187:Disaccharides; D004586:Electrophoresis; D005944:Glucosamine / Q000378:metabolism; D006596:Hexosaminidases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D007700:Kinetics; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet; D013997:Time Factors
D000081:Acetamides; D003470:Culture Media; D004187:Disaccharides; D000135:Acid Phosphatase; D006596:Hexosaminidases; D002688:Chitinases; D005944:Glucosamine