Biochemical characterization of an extracellular polyextremophilic α-amylase from the halophilic archaeon Halorubrum xinjiangense
Autor: | Ahmad Reza Shahverdi, Mahsa Moshfegh, Gholamreza Zarrini, Mohammad Ali Faramarzi |
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Rok vydání: | 2013 |
Předmět: |
Chromatography
Molecular mass biology Chemistry Archaeal Proteins Hydrolysis Starch Fast protein liquid chromatography General Medicine biology.organism_classification Microbiology Kinetics Biochemistry Affinity chromatography Enzyme Stability biology.protein Molecular Medicine Amylase Halorubrum alpha-Amylases Alpha-amylase Ethanol precipitation |
Zdroj: | Extremophiles. 17:677-687 |
ISSN: | 1433-4909 1431-0651 |
DOI: | 10.1007/s00792-013-0551-7 |
Popis: | An extracellular haloalkaliphilic thermostable α-amylase producing archaeon was isolated from the saltwater Lake Urmia and identified as Halorubrum xinjiangense on the basis of morphological, biochemical, and molecular properties. The enzyme was purified to an electrophoretically homogenous state by 80 % cold ethanol precipitation, followed by affinity chromatography. The concentrated pure amylase was eluted as a single peak on fast protein liquid chromatography. The molecular mass of the purified enzyme was about 60 kDa, with a pI value of 4.5. Maximum amylase activity was at 4 M NaCl or 4.5 M KCl, 70 °C, and pH 8.5. The K m and V max of the enzyme were determined as 3.8 mg ml(-1) and 12.4 U mg(-1), respectively. The pure amylase was stable in the presence of SDS, detergents, and organic solvents. In addition, the enzyme (20 U) hydrolyzed 69 % of the wheat starch after a 2-h incubation at 70 °C in an aqueous/hexadecane two-phase system. |
Databáze: | OpenAIRE |
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