Suppressed Native Hydrolytic Activity of a Lipase to Reveal Promiscuous Michael Addition Activity in Water

Authors

  • Maria Svedendahl,

    1. Division of Biochemistry, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center, SE-106 91 Stockholm (Sweden), Fax: (+46) 8-5537-8468
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  • Biljana Jovanović,

    1. Division of Biochemistry, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center, SE-106 91 Stockholm (Sweden), Fax: (+46) 8-5537-8468
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  • Linda Fransson,

    1. Division of Biochemistry, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center, SE-106 91 Stockholm (Sweden), Fax: (+46) 8-5537-8468
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  • Per Berglund Prof.

    1. Division of Biochemistry, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center, SE-106 91 Stockholm (Sweden), Fax: (+46) 8-5537-8468
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Abstract

Suppression of the native hydrolytic activity of Pseudozyma antarctica lipase B (PalB) (formerly Candida antarctica lipase B) in water is demonstrated. By replacing the catalytic Ser 105 residue with an alanine unit, promiscuous Michael addition activity is favored. A Michael addition reaction between methyl acrylate and acetylacetone was explored as a model system. For the PalB Ser 105 Ala mutant, the hydrolytic activity was suppressed more than 1000 times and, at the same time, the Michael addition activity was increased by a factor of 100. Docking studies and molecular dynamics simulations revealed an increased ability of the PalB Ser 105 Ala mutant to harbor the substrates close to a catalytically competent conformation.

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