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Conference abstract2005

PDAT genetically modified to a soluble enzyme shows high substrate flexibility

Ekman Åsa, Stymne Sten, Ståhl Ulf, Banaś Antoni, Alokesh Goshal, Dahlqvist Anders

Abstract

The predicted cytosolic and membrane spanning region of the N-terminal part of the yeast (S. cerevisiae) PDAT gene was deleted and the remaining C-terminal part of the gene was expressed in Pichia pastoris behind a methanol induced promoter with the α-factor secretion signal in frame at the N-terminal end. The transformed Pichia secreted a soluble PDAT with high catalytic activity. The substrate specificities of the soluble PDAT were investigated. Although the preferred substrates were, like the microsomal bound enzyme, sn-2 - phosphatidylethanolamine as acyl donor and sn-1,2-diacylglycerols as acyl acceptor, the soluble enzyme showed a high flexibility in substrate specificity. The enzyme could transfer acyl groups from either sn-1,sn-2 and sn-3 positions of one lipid to either the sn-1, sn-2 or sn- 3 positions of another lipid. Moreover, both phospholipids and neutral lipids could be utilized both as acyl donors and acceptors. Most remarkable, PDAT could also catalyze the cleavage of the head group of phospholipids, i.e. act as a phospholipase C. Thus, the soluble PDAT could synthesize triacylglycerols utilizing only neutral lipids or only phospholipids. Due to its low lipase activity, the soluble PDAT has a great potential as an alternative to industrial lipases in transacylation reaction since it can operate in aqueous environments . How many of the enzymatic reactions performed by the soluble PDAT which also is carried out in-vivo by the membrane bound enzyme remains to be tested

Published in

Conference

2005 Biochemistry and Molecular Biology of Plant Fatty Acids and Glycerolipids Symposium

      SLU Authors

    • Grimberg, Åsa

      • Department of Crop Science, Swedish University of Agricultural Sciences

      • Stymne, Sten

        • Department of Crop Science, Swedish University of Agricultural Sciences

        • Ståhl, Ulf

          • Department of Crop Science, Swedish University of Agricultural Sciences

        UKÄ Subject classification

        Agricultural Science
        Food Science

        Permanent link to this page (URI)

        https://res.slu.se/id/publ/6756