Substrate Specificity and Stereoselectivity of Two Sulfolobus 2-Keto-3-deoxygluconate Aldolases towards Azido-Substituted Aldehydes

Authors

  • Dr. Marloes Schurink,

    1. Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen (The Netherlands), Fax: (+31) 317-484914
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  • Dr. Suzanne Wolterink-van Loo,

    1. Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen (The Netherlands)
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  • Prof. Dr. John van der Oost,

    1. Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen (The Netherlands)
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  • Dr. Theo Sonke,

    1. DSM Innovative Synthesis B.V. P.O. Box 18,6160 MD Geleen (The Netherlands)
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  • Dr. Maurice C. R. Franssen

    Corresponding author
    1. Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen (The Netherlands), Fax: (+31) 317-484914
    • Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen (The Netherlands), Fax: (+31) 317-484914

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Abstract

The 2-keto-3-deoxygluconate aldolases (KDGAs) isolated from Sulfolobus species convert pyruvate and glyceraldehyde reversibly into 2-keto-3-deoxygluconate and -galactonate. As a result of their high thermostability and activity on nonphosphorylated substrates, KDGA enzymes have potential as biocatalysts for the production of building blocks for fine chemical and pharmaceutical applications. Up to now, wild-type enzymes have only shown moderate stereocontrol for their natural reaction. However, if a set of azido-functionalized aldehydes were applied as alternative acceptors in the reaction with pyruvate, the stereoselectivity was strongly increased to give enantiomeric or diastereomeric excess values up to 97 %. The Sulfolobus acidocaldarius KDGA displayed a higher stereoselectivity than Sulfolobus solfataricus KDGA for all tested reactions. The azido-containing products are useful chiral intermediates in the synthesis of nitrogen heterocycles.

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