1. Differential calmodulin-modulatory and electron transfer properties of neuronal nitric oxide synthase mu compared to the alpha variant.
- Author
-
Panda SP, Li W, Venkatakrishnan P, Chen L, Astashkin AV, Masters BS, Feng C, and Roman LJ
- Subjects
- Amino Acid Sequence physiology, Animals, Calmodulin chemistry, Cytochromes c metabolism, Electron Transport physiology, Flavin Mononucleotide metabolism, Heme chemistry, Heme metabolism, Isoenzymes chemistry, Isoenzymes physiology, Nitric Oxide biosynthesis, Nitric Oxide Synthase Type I chemistry, Protein Binding, Rats, Calmodulin metabolism, Nitric Oxide Synthase Type I physiology
- Abstract
Neuronal nitric oxide synthase μ (nNOSμ) contains 34 additional residues in an autoregulatory element compared to nNOSα. Cytochrome c and flavin reductions in the absence of calmodulin (CaM) were faster in nNOSμ than nNOSα, while rates in the presence of CaM were smaller. The magnitude of stimulation by CaM is thus notably lower in nNOSμ. No difference in NO production was observed, while electron transfer between the FMN and heme moieties and formation of an inhibitory ferrous-nitrosyl complex were slower in nNOSμ. Thus, the insert affects electron transfer rates, modulation of electron flow by CaM, and heme-nitrosyl complex formation., (© 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF