Open AccessAn NAD(P)H-Nicotine Blue Oxidoreductase Is Part of the Nicotine Regulon and May Protect Arthrobacter nicotinovorans from Oxidative Stress during Nicotine Catabolism
Author(s) -
Marius Mihăşan,
Calin-Bogdan Chiribau,
Thorsten Friedrich,
Vlad Artenie,
Roderich Brandsch
Publication year - 2007
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02668-06
Subject(s) - regulon , nicotine , nad+ kinase , oxidative stress , oxidoreductase , catabolism , chemistry , arthrobacter , biochemistry , oxidative phosphorylation , microbiology and biotechnology , biology , metabolism , enzyme , bacterial protein , gene , neuroscience
An NAD(P)H-nicotine blue (quinone) oxidoreductase was discovered as a member of the nicotine catabolic pathway ofArthrobacter nicotinovorans . Transcriptional analysis and electromobility shift assays showed that the enzyme gene was expressed in a nicotine-dependent manner under the control of the transcriptional activator PmfR and thus was part of the nicotine regulon ofA. nicotinovorans . The flavin mononucleotide-containing enzyme uses NADH and, with lower efficiency, NADPH to reduce, by a two-electron transfer, nicotine blue to the nicotine blue leuco form (hydroquinone). Besides nicotine blue, several other quinones were reduced by the enzyme. The NAD(P)H-nicotine blue oxidoreductase may prevent intracellular one-electron reductions of nicotine blue which may lead to semiquinone radicals and potentially toxic reactive oxygen species.