The 58 kDa mouse selenoprotein is a BCNU‐sensitive thioredoxin reductase

FEBS Letters

Becker, Katja¹  Gromer, Stephan¹  Schirmer, R.Heiner¹ 

[1] Biochemie-Zentrum der Universität Heidelberg, 5. OG, Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany

关键词: Chemotherapy;    Malaria;    Selenoenzyme purification;    Thioredoxin reductase;    Glutathione reductase;    Mouse EAT cell;    BCNU;    1;    3-bis-(2-chloroethyl)-1-nitrosourea;    DTNB;    5;    5′-dithiobis-(2-nitrobenzoic acid);    PMSF;    phenylmethylsulfonylfluoride;    TE buffer;    50 mM Tris-HCl;    1 mM EDTA;    adjusted to pH 7.6 at room temperature;    TrxR;    thioredoxin reductase;    GR;    glutathione reductase;   

DOI  :  10.1016/S0014-5793(97)00816-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The flavoprotein thioredoxin reductase [EC 1.6.4.5] (NADPH+H⁺+thioredoxin-S₂→NADP⁺+thioredoxin-(SH)₂) was isolated from mouse Ehrlich ascites tumour (EAT) cells. Like the counterpart from human placenta but unlike the known thioredoxin reductases from non-vertebrate organisms, the mouse enzyme was found to contain 1 equivalent of selenium per subunit of 58 kDa. The K _M values were 4.5 μM for NADPH, 480 μM for DTNB and 36 μM for Escherichia coli thioredoxin, the turnover number with DTNB being ≈40 s⁻¹. As mouse is a standard animal model in cancer and malaria research, thioredoxin reductase and glutathione reductase [EC 1.6.4.2] from EAT cells were compared with each other. While both enzymes in their 2-electron reduced form are targets of the cytostatic drug carmustine (BCNU), no immunologic cross-reactivity between the two mouse disulfide reductases was observed.

【 授权许可】

Unknown