title: Enzymatic properties of a thermostable α-glucosidase from acidothermophilic crenarchaeon Sulfolobus tokodaii strain 7.
abstract: We have characterized the putative α-glucosidase gene (st2525) selected by total genome analysis from the acidothermophilic crenarchaeon Sulfolobus tokodaii strain 7. The ORF was cloned and expressed as a fusion protein in Escherichia coli, and recombinant ST2525 was purified by Ni-NTA affinity chromatography. Maximum activity was observed at 95°C and pH 4.0, and the enzyme exhibited stability with half-lives of 40.1 min and 7.75 min at extremely high temperatures of 100°C and 105°C, respectively. The enzyme retained at least 85% of its maximal activity in the pH range of 4.0-11.0. ST2525 exclusively hydrolyzed α-1,4-glycosidic linkages of oligosaccharides in an exo-type manner, with highest catalytic efficiency toward maltotriose. The enzyme also displayed transglycosylation activity, converting maltose to isomaltose, panose, maltotriose, isomaltotriose, etc. From these results, ST2525 could be potentially useful for starch hydrolysis as well as novel synthesis of oligosaccharides in industry.
authors: Department of Food Science and Nutrition, College of Human Ecology, Pusan National University, Busan 609-735, Korea.
authors: Jung-Eun
authors: JE
authors: Park
authors: So Hae
authors: SH
authors: Park
authors: Jung Yoon
authors: JY
authors: Woo
authors: Hye Sun
authors: HS
authors: Hwang
authors: Jaeho
authors: J
authors: Cha
authors: Heeseob
authors: H
authors: Lee
mesh_terms: D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013213:Starch / Q000378:metabolism; D013379:Substrate Specificity; D016944:Sulfolobus / Q000201:enzymology* / Q000235:genetics; D013696:Temperature; D000520:alpha-Glucosidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D013213:Starch; D000520:alpha-Glucosidases