Purification and properties of the cell-associated beta-xylosidase from Aureobasidium.
beta-Xylosidase was extracted from Aureobasidium sp. ATCC 20524 and purified to homogeneity. The molecular mass was estimated at 411 kDa. The enzyme contained 15.3% (w/w) carbohydrate. The optimum pH and temperature were pH 3.5 and 80 degrees C, respectively. The enzyme was stable at pH 3.5-9 after 3 h and at 80 degrees C after 15 min. The Michaelis constant (K(m)) and maximum velocity (V(max)) toward p-nitrophenyl-beta-D-xyloside were 2.0 mmol l(-1) and 0.94 mmol min(-1) mg(-1) protein, respectively. The enzyme was inhibited strongly by mercury, lead, and copper ions.
Hayashi
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S
Faculty of Engineering, Department of Applied Chemistry, Miyazaki University, Miyazaki 889-2192, Japan.
Ohno
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T
Ito
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Yokoi
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H
D003300:Copper / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007854:Lead / Q000494:pharmacology; D008628:Mercury / Q000494:pharmacology; D003904:Mitosporic Fungi / Q000201:enzymology* / Q000254:growth & development; D008970:Molecular Weight; D013379:Substrate Specificity; D013696:Temperature; D014995:Xylosidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*
D007854:Lead; D003300:Copper; D014995:Xylosidases; D008628:Mercury