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

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• 作者：Anusevicius ; Zilvinas ; &Scaron ; arlauskas ; Jonas ; Nivinskas ; Henrikas ; Segura-Aguilar ; Juan ; et. al.
• 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 ; thi
• 刊名：FEBS Letters
• 出版年：1998
• 出版时间：October 2, 1998
• 年：1998
• 卷：436
• 期：2
• 页码：144-148
• 全文大小：162 K

文摘

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.