A reduced pyridine nucleotides-diaphorase activity associated to the assimilatory nitrite reductase complex from Neurospora crassa.
Archives of microbiology
confidence
Key findings
Biochemical characterization of NAD(P)H-diaphorase activity associated with the assimilatory nitrite reductase complex; no clinical/biological endpoints.
View source on PubMed (PMID 136235) ↗
- Sample size
- N/A
- Population
- Neurospora crassa (fungal enzyme study, in vitro)
- Dosing
- N/A
- Duration
- N/A
- Route
- in vitro
- Blinding
- not_reported
- Controls
- none
- Drug class
- coenzyme
Full abstract
The Neurospora crassa assimilatory NAD(P)H-nitrite reductase complex has associated a NAD(P)H-diaphorase activity. 1. This NAD(P)H-diaphorase activity can use either mammalian cytochrome c, 2,6--dichlorophenol-indophenol, ferricyanide, or menadione as electron acceptor from the reduced pyridine nucleotides, and requires flavin adenine dinucleotide for maximal activity. 2. It is inhibited by p-hydroxymercuribenzoate, 1 muM, and it is unaffected by cyanide, sulfite, or arsenite at concentrations which completely inhibit the NAD(P)H-nitrite reductase activity. 3. Flavin adenine dinucleotide specifically protects the NAD(P)H-diaphorase activities, but not the NAD(P)H-nitrite reductase activities, against thermal inactivation. 4. In vitro preincubation of the Neurospora crassa nitrite reductase complex with reduced pyridine nucleotides plus flavin adenine dinucleotide inactivates the NAD(P)H-nitrite reductase activities, but does not affect the NAD(P)H-diaphorase activities, indicating that this nitrite reductase inactivation occurs in the part of the enzyme that contain the nitrite reducing center.