DT‐diaphorase catalyzes N‐denitration and redox cycling of tetryl

FEBS Letters

Segura-Aguilar, Juan¹  Anusevičius, Žilvinas²  Šarlauskas, Jonas²  Č≐nas, Narimantas²  Nivinskas, Henrikas² 

[1] Division of Biochemistry, Department of Pharmaceutical Biosciences, BMC, Uppsala University, S-751 23 Uppsala, Sweden;Institute of Biochemistry, Mokslininkų 12, Vilnius 2600, Lithuania

关键词: DT-diaphorase;    Tetryl;    N-nitramine;    Explosive;    Redox cycling;    Electron transfer;    FNR;    ferredoxin:NADP+ reductase;    k cat;    catalytic constant;    k cat/K m;    bimolecular rate constant;    SOD;    superoxide dismutase;    TLC;    thin layer chromatography;   

DOI  :  10.1016/S0014-5793(98)01115-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Rat liver DT-diaphorase (EC 1.6.99.2) catalyzed reductive N-denitration of tetryl (2,4,6-tri-nitrophenyl-N-methylnitramine) and 2,4-dinitrophenyl-N-methylnitramine, oxidizing the excess of NADPH. The reactions were accompanied by oxygen consumption and superoxide dismutase-sensitive reduction of added cytochrome c and reductive release of Fe²⁺ from ferritin. Quantitatively, the reactions of DT-diaphorase proceeded like single-electron reductive N-denitration of tetryl by ferredoxin:NADP⁺ reductase (EC 1.18.1.2) (Shah, M.M. and Spain, J.C. (1996) Biochem. Biophys. Res. Commun. 220, 563–568), which was additionally checked up in this work. Thus, although reductive N-denitration of nitrophenyl-N-nitramines is a net two-electron (hydride) transfer process, DT-diaphorase catalyzed the reaction in a single-electron way. These data point out the possibility of single-electron transfer steps during obligatory two-electron (hydride) reduction of quinones and nitroaromatics by DT-diaphorase.

【 授权许可】

Unknown