Isolation of the Tetrathionate Hydrolase from Thiobacillus Acidophilus

Authors

  • Govardus A. H. De Jong,

    1. Kluyver Laboratory of Biotechnology, Department of Microbiology and Enzymology, Delft, The Netherlands
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  • Wim Hazeu,

    1. Kluyver Laboratory of Biotechnology, Department of Microbiology and Enzymology, Delft, The Netherlands
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  • Piet Bos,

    1. Kluyver Laboratory of Biotechnology, Department of Microbiology and Enzymology, Delft, The Netherlands
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  • J Gijs Kuenen

    Corresponding author
    1. Kluyver Laboratory of Biotechnology, Department of Microbiology and Enzymology, Delft, The Netherlands
      J. G. Kuenen, Kluyver Laboratory of Biotechnology, Department of Microbiology and Enzymology, Julianalaan 67, 2628 BC Delft, The Netherlands
      Fax:+31 15 2782355.
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J. G. Kuenen, Kluyver Laboratory of Biotechnology, Department of Microbiology and Enzymology, Julianalaan 67, 2628 BC Delft, The Netherlands
Fax:+31 15 2782355.

Abstract

An enzyme capable of hydrolysing tetrathionate was purified from cell-free extracts of Thiobacillus acidophilus. The purified enzyme converts tetrathionate into thiosulfate, sulfur and sulfate. In addition, pentathionate could also be converted by the same enzyme. Measurement of the enzyme activity during purification is based on the absorbance of the initial intermediates formed from tetrathionate in the ultraviolet region, which have not been identified. Enzyme activity could also be measured by the scattering of insoluble sulfur in the visible region. The purified enzyme has a pH optimum of 2.5 and a temperature optimum of 65°C. Enzyme activity is strongly stimulated by the presence of sulfate ions. The purified enzyme is a dimer with two identical subunits of 48kDa. The ultraviolet–visible absorption spectra and denaturation experiments indicate the presence of an organic cofactor.

Enzymes
 

Isocitric dehydrogenase (EC 1.1.1.42)

 

alcohol dehydrogenase (EC 1.1.1.1)

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