title: Purification and characterization of a thermostable beta-1,3-1,4-glucanase from Laetiporus sulphureus var. miniatus.
abstract: A beta-1,3-1,4-glucanase from the fungus Laetiporus sulphureus var. miniatus was purified as a single 26 kDa band by ammonium sulfate precipitation, HiTrap Q HP, and UNO Q ion-exchange chromatography, with a specific activity of 29 U/mg. The molecular mass of the native enzyme was 52 kDa as a dimer by gel filtration. beta-1,3-1,4-Glucanase showed optimum activity at pH 4.0 and 75 degrees . The half-lives of the enzyme at 70 degrees and 75 degrees were 152 h and 22 h, respectively. The enzyme showed the highest activity for barley beta- glucan as beta-1,3-1,4-glucan among the tested polysaccharides and p-nitrophenyl-beta-D-glycosides with a K(m) of 0.67 mg/ml, a k(cat) of 13.5 s(-1) and a k(cat)/K(m) of 20 mg/ml/s.
authors.affiliation: Department of Bioscience and Biotechnology, Konkuk University, Seoul 143-701, Korea.
authors.forename: Mi-Ri
authors.initials: MR
authors.lastname: Hong
authors.forename: Yeong-Su
authors.initials: YS
authors.lastname: Kim
authors.forename: Ah-Reum
authors.initials: AR
authors.lastname: Joo
authors.forename: Jung-Kul
authors.initials: JK
authors.lastname: Lee
authors.forename: Yeong-Suk
authors.initials: YS
authors.lastname: Kim
authors.forename: Deok-Kun
authors.initials: DK
authors.lastname: Oh
mesh_terms: D055453:Coriolaceae / Q000201:enzymology*; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D007700:Kinetics; D008970:Molecular Weight; D013379:Substrate Specificity; D013696:Temperature; D047071:beta-Glucans / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D006027:Glycosides; D047071:beta-Glucans; C067858:beta-glucan, (1-3)(1-4)-; D006026:Glycoside Hydrolases