title: Isolation and characterization of a novel thermostable alpha-amylase from Korean pine seeds.
abstract: Amylases have significant importance in broad industrial application including bio-ethanol production. Although amylases are widely distributed in microbes, plants and animals, it has been sought for new amylases from various sources with special industrial potential. In this study we firstly isolated and characterized a novel thermostable alpha-amylase from Korean pine seed. Enzyme was purified to homogeneity level with purification fold of 1286.1 using several techniques such as self-precipitation, (NH(4))(2)SO(4) fractionation, DEAE anion exchange and starch affinity chromatography. The purified alpha-amylase showed two bands in SDS-PAGE with molecular weight of 44 and 45 kDa. The apparent molecular weight of native enzyme was calculated to be 46.7 kDa. Internal peptide sequencing confirmed that the purified alpha-amylase was a novel enzyme. The optimum pH and temperature for enzyme activity were pH 4.5 and 65 degrees C, respectively. This enzyme was fully stable for 48h at 50 degrees C and retained 80% activity up to 96h. The K(m) and V(max) were 0.84 mg/ml and 3.71 micromol/min, respectively. On the basis of high thermal stability and a broad range of pH stability, the pine seed alpha-amylase showed a good prospect of industrial application.
authors.affiliation: Department of Animal Science and Biotechnology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Md Abul Kalam
authors.initials: MA
authors.lastname: Azad
authors.forename: Jae-Han
authors.initials: JH
authors.lastname: Bae
authors.forename: Jong-Sang
authors.initials: JS
authors.lastname: Kim
authors.forename: Jin-Kyu
authors.initials: JK
authors.lastname: Lim
authors.forename: Kyung-Sik
authors.initials: KS
authors.lastname: Song
authors.forename: Beom-Soo
authors.initials: BS
authors.lastname: Shin
authors.forename: Hak-Ryul
authors.initials: HR
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability / Q000187:drug effects; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007477:Ions; D007700:Kinetics; D007723:Korea; D008670:Metals / Q000494:pharmacology; D008969:Molecular Sequence Data; D028223:Pinus / Q000201:enzymology*; D012639:Seeds / Q000187:drug effects / Q000201:enzymology*; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D012995:Solubility / Q000187:drug effects; D013379:Substrate Specificity / Q000187:drug effects; D013696:Temperature; D000516:alpha-Amylases / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D007477:Ions; D008670:Metals; D000516:alpha-Amylases