Abstract
Summary The assimilatory nitrite reductase from the cyanobacterium Anabaena sp. 7119 (formerly designated Nostoc muscorum ) is an adaptive enzyme whose synthesis is nutritionally repressed by the presence of ammonia in the culture medium. The enzyme is a soluble protein and catalyzes the stoichiometric reduction of nitrite to ammonia. In crude extracts, ferredoxin is an efficient electron donor when reduced either photosynthetically with subcellular particles, enzymatically with a NADPH-generating system and NADP reductase, or chemically with dithionite. However, a 763-fold purified nitrite reductase preparation catalyzes the reduction of nitrite with ferredoxin chemically reduced with dithionite, but it is ineffective when reduced either photosynthetically or enzymatically. Hydroxylamine and cyanide are competitive inhibitors with respect to nitrite of the ferredoxin- nitrite reductase (EC. 1.7.7.1.). The enzymatic activity is also inhibited by o-phenanthroline and sulfite, but not by p-hydroxymercuribenzoate.
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.