Selenite Reduction by the Thioredoxin System : Kinetics and Identification of Protein-Bound Selenide

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Author(s)

    • Sato Kumi SATO Kumi
    • Department of Bioresources Chemistry, Graduate School of Natural Science and Technology, Okayama University
    • IMAI Takeshi
    • Department of Bioresources Chemistry, Graduate School of Natural Science and Technology, Okayama University
    • KUWAHARA Mitsuhiko
    • Department of Bioresources Chemistry, Graduate School of Natural Science and Technology, Okayama University
    • OKUGOCHI Takahiro
    • Department of Bioresources Chemistry, Graduate School of Natural Science and Technology, Okayama University
    • MIHARA Hisaaki
    • Laboratory of Molecular Microbial Science, Institute for Chemical Research, Kyoto University
    • ESAKI Nobuyoshi
    • Laboratory of Molecular Microbial Science, Institute for Chemical Research, Kyoto University
    • INAGAKI Kenji
    • Department of Bioresources Chemistry, Graduate School of Natural Science and Technology, Okayama University

Abstract

Selenite (SeO<SUB>3</SUB><SUP>2−</SUP>) assimilation into a bacterial selenoprotein depends on thioredoxin (trx) reductase in <I>Esherichia coli</I>, but the molecular mechanism has not been elucidated. The mineral-oil overlay method made it possible to carry out anaerobic enzyme assay, which demonstrated an initial lag-phase followed by time-dependent steady NADPH consumption with a positive cooperativity toward selenite and trx. SDS-PAGE/autoradiography using <SUP>75</SUP>Se-labeled selenite as substrate revealed the formation of trx-bound selenium in the reaction mixture. The protein-bound selenium has metabolic significance in being stabilized in the divalent state, and it also produced the selenopersulfide (-S-SeH) form by the catalysis of <I>E. coli</I> trx reductase (TrxB).

Journal

  • Bioscience, Biotechnology, and Biochemistry

    Bioscience, Biotechnology, and Biochemistry 75(6), 1184-1187, 2011-06-23

    Japan Society for Bioscience, Biotechnology, and Agrochemistry

References:  27

Codes

  • NII Article ID (NAID)
    10029328515
  • NII NACSIS-CAT ID (NCID)
    AA10824164
  • Text Lang
    ENG
  • Article Type
    NOT
  • ISSN
    09168451
  • NDL Article ID
    11132032
  • NDL Source Classification
    ZR7(科学技術--農林水産--農産) // ZR2(科学技術--生物学--生化学) // ZP1(科学技術--化学・化学工業)
  • NDL Call No.
    Z53-G223
  • Data Source
    CJP  NDL  J-STAGE 
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