title: [Purification and characterization of alginate lyase from marine bacterium Vibrio sp. QY101].
abstract: Extracellular alginate lyase secreted by Vibrio sp. QY101, which was isolated from brown algae, was purified to homogeneity by a combination of ammonium sulfate precipitation, DEAE-Sepharose Fast Flow anion-exchange chromatography and Superdex 75 gel filtration chromatography. Its molecular mass was 39 kD as determined by SDS-PAGE analysis. The enzyme had an optimal temperature of 30 degrees for its activity, and was most active at pH 7.5. The thermal and pH stability were 0-30 degrees, and pH 6.5-8.5, respectively. The enzyme activity was stimulated by 0.5 mol/L NaCl, 1.0 mmol/L Ca(2+) or 5.0 mmol/L (Mn(2+), and inhibited by 5.0 mmol/L Ni(2+), 1.0 mmol/L Fe2+) or 1.0 mmol/L EDTA. Preliminary analysis on substrate specificity showed that this alginate lyase had activity on both poly-alpha 1,4-L-guluronate and poly-beta1,4-D-mannuronate substrates.
authors.affiliation: Institute of Marine Drug and Food, Ocean University of China, Qingdao 266003, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Song
authors.forename: Wen-Gong
authors.initials: WG
authors.lastname: Yu
authors.forename: Feng
authors.initials: F
authors.lastname: Han
authors.forename: Wen-Jun
authors.initials: WJ
authors.lastname: Han
authors.forename: Jing-Bao
authors.initials: JB
authors.lastname: Li
mesh_terms: D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D008970:Molecular Weight; D011133:Polysaccharide-Lyases / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature; D014733:Vibrio / Q000201:enzymology*
chemical_list: D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase