Abstract
In vitro inactivation of Neurospora crassa nitrite reductase (NAD(P)H: nitrite oxidoreductase, EC 1.6.6.4) can be obtained by preincubation of the enzyme with reduced pyridine nucleotide plus FAD. The presence of nitrite or hydroxylamine, electron acceptors for the N. crassa nitrite reductase, or cyanide, sulfite or arsenite, competitive inhibitors with respect to nitrite of this enzyme, protects the enzyme against this inactivation. Anaerobic experiments reveal that oxygen is required in order to obtain complete inactivation of nitrite reductase by preincubation with reduced pyridine nucleotide plus FAD. Also, inactivation is prevented if catalase is included in the preincubation mixture. The presence of hydrogen peroxide in the preincubation mixture increases the sensitivity of nitrite reductase to the in vitro FAD-dependent NAD(P)H inactivation. Neither electron acceptors, competitive inhibitors nor catalase, agents which protect the enzyme against the FAD-dependent NAD(P)H inactivation, can reverse this process once it has occurred.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.