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l-Threonine dehydratase activity of axenically grown Hartmannella culbertsoni

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  1. 1.

    l-Threonine dehydratase (E.C. activity in the cell-free extracts of the trophozoites of Hartmannella culbertsoni has been purified 20-fold.

  2. 2.

    The enzyme requires pyridoxal-5-phosphate for its activity and is not cold-labile. Kinetic studies have shown that there is homotropic cooperative interaction between the substrate molecules. The enzyme is susceptible to end-product regulation, l-isoleucine being a feed back inhibitor and l-valine can partially reactivate the l-isoleucine inhibited enzyme. Some nucleotides stimulate the activity of the enzyme indicating allosteric nature of the enzyme.

  3. 3.

    Certain amoebicidal drugs and antibiotics have marked inhibitory effect on the enzyme.

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Communication no. 1538 from the Central Drug Research Institute, Lucknow, India.

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Raizada, M.K., Mohan Rao, V.K. l-Threonine dehydratase activity of axenically grown Hartmannella culbertsoni . Archiv. Mikrobiol. 84, 119–128 (1972). https://doi.org/10.1007/BF00412432

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  • Enzyme
  • Nucleotide
  • Kinetic Study
  • Substrate Molecule
  • Cooperative Interaction