title: Gene cloning and characterization of thermostable lipase from Bacillus stearothermophilus L1.
abstract: The gene coding for an extracellular lipase of Bacillus stearothermophilus L1 was cloned in Escherichia coli. Sequence analysis showed an open reading frame of 1254 bp, which encodes a polypeptide of 417 amino acid residues. The polypeptide was composed of a signal sequence (29 amino acids) and a mature protein of 388 amino acids. An alanine replaces the first glycine in the conserved pentapeptide (Gly-X-Ser-X-Gly) around the active site serine. The expressed lipase was purified by hydrophobic interaction and ion exchange chromatography using buffers containing 0.02% (v/v) Triton X-100. The lipase was most active at 60-65 degrees C and in alkaline conditions around pH 9-10. The lipase had highest activity toward p-nitrophenyl caprylate among the synthetic substrates and tripropionin among the triglycerides. It hydrolyzed beef tallow and palm oil more rapidly than olive oil at 50 degrees C.
authors.affiliation: Korea Research Institute of Bioscience & Biotechnology (KRIBB), Taejon, Korea.
authors.forename: H K
authors.initials: HK
authors.lastname: Kim
authors.forename: S Y
authors.initials: SY
authors.lastname: Park
authors.forename: J K
authors.initials: JK
authors.lastname: Lee
authors.forename: T K
authors.initials: TK
authors.lastname: Oh
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004795:Enzyme Stability; D005798:Genes, Bacterial; D001411:Geobacillus stearothermophilus / Q000201:enzymology* / Q000235:genetics; D006361:Heating; D008049:Lipase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D008049:Lipase