title: Purification and characterization of a new xylanase (xylanase B) produced by Streptomyces lividans 66.
abstract: A new extracellular xylanase produced by Streptomyces lividans 66 was isolated from a genetically engineered clone of that strain. This enzyme, named xylanase B, has an Mr of 31,000 and acts specifically on xylan as an endo-type xylanase producing short-chain xylo-oligosaccharides. The activity is optimal at pH 6.5 and at a temperature of 55 degrees C, which is similar to that of the previously characterized xylanase A. Xylanase B is glycosylated and has a pI of 8.4; its Km and Vmax. values are 3.71 mg/ml and 1.96 mmol/mg of enzyme respectively. Specific antibodies raised against xylanase A show no cross-reaction with xylanase B; however, the anti-(xylanase B) antibodies react slightly with xylanase A. A comparison of the hydrolysis products obtained from oat-spelts xylan with both enzymes show that xylanase A preferentially degrades short-chain oligo-xylosides, whereas xylanase B acts on the longer, water-insoluble, molecules.
authors.affiliation: Centre de Recherche en Microbiologie Appliquée, Institut Armand-Frappier, Université du Québec, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Kluepfel
authors.forename: S
authors.initials: S
authors.lastname: Vats-Mehta
authors.forename: F
authors.initials: F
authors.lastname: Aumont
authors.forename: F
authors.initials: F
authors.lastname: Shareck
authors.forename: R
authors.initials: R
authors.lastname: Morosoli
mesh_terms: D015153:Blotting, Western; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D006026:Glycoside Hydrolases / Q000302:isolation & purification* / Q000378:metabolism; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007526:Isoelectric Point; D008970:Molecular Weight; D013302:Streptomyces / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature; D043325:Xylan Endo-1,3-beta-Xylosidase; D014990:Xylans / Q000378:metabolism
chemical_list: D014990:Xylans; D006026:Glycoside Hydrolases; D043325:Xylan Endo-1,3-beta-Xylosidase