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Nitrite reductase activity is a novel function of mammalian mitochondria
Author(s) -
Kozlov Andrey V,
Staniek Katrin,
Nohl Hans
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00788-7
Subject(s) - nitric oxide , nitrite , chemistry , biochemistry , mitochondrion , nitrite reductase , respiratory chain , nitric oxide synthase , cellular respiration , superoxide , nitrosation , respiration , electron transport chain , mitochondrial respiratory chain , enzyme , biology , nitrate , organic chemistry , botany
Nitrite, which is the major stable degradation product of nitric oxide, exists in all tissues capable of nitric oxide synthesis from L ‐arginine. The present study provides experimental evidence that nitrite in contact with respiring mitochondria accepts reducing equivalents from the ubiquinone cycle of the respiratory chain. Univalent reduction of nitrite was totally inhibited by myxothiazol. We therefore conclude on the involvement of redox cycling that ubisemiquinone is associated with the bc 1 complex. Recycling of nitric oxide degradation products via these electron carriers may become a threat to energy‐linked respiration since nitric oxide in direct contact with mitochondria was shown to slow the energy‐linked respiration down and to trigger a mitochondrial source for superoxide radicals. Until now, the existence of nitrite reductase activity was only demonstrated in plants and bacteria. In addition, the present observation elucidates the existence of a nitric oxide synthase‐independent nitric oxide source.