Abstract
A bacterium with lipolytic activity was isolated from the Chukchi Sea within the Arctic Ocean. The lipase BpL5 from the isolate, Bacillus pumilus ArcL5, belongs to subfamily 4 of lipase family I. The optimum pH and temperature of the recombinant enzyme BpL5, as expressed in Escherichia coli, were 9.0 and 20 °C, respectively. The enzyme retained 85 % of its activity at 5 °C. There was a significant difference between temperatures for maximal activity (20 °C) and for protein denaturation (approx. 45 °C). The enzyme preferred middle-chain (C8) p-nitrophenyl substrates. Two mutants, S139A and S139Y, were rationally designed based on the 3D-structure model, and their activities were compared with that of the wild type. The both mutants showed significantly improved activity against tricaprylin.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Substitution
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Arctic Regions
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Bacillus / enzymology*
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Bacillus / isolation & purification
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DNA, Bacterial / chemistry
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DNA, Bacterial / genetics
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Enzyme Stability
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Escherichia coli / genetics
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Hydrogen-Ion Concentration
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Lipase / chemistry
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Lipase / genetics
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Lipase / isolation & purification
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Lipase / metabolism*
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Models, Molecular
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Molecular Sequence Data
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Mutagenesis, Site-Directed
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Mutant Proteins / genetics
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Mutant Proteins / isolation & purification
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Mutant Proteins / metabolism
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Oceans and Seas
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Protein Conformation
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / isolation & purification
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Recombinant Proteins / metabolism
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Seawater / microbiology
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Sequence Analysis, DNA
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Substrate Specificity
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Temperature
Substances
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DNA, Bacterial
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Mutant Proteins
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Recombinant Proteins
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Lipase