Format

Send to

Choose Destination
See comment in PubMed Commons below
J Inorg Biochem. 2008 Sep;102(9):1777-82. doi: 10.1016/j.jinorgbio.2008.05.008. Epub 2008 May 29.

Reactions of ferrous neuroglobin and cytoglobin with nitrite under anaerobic conditions.

Author information

1
Department of Biological Sciences, University of Aarhus, Building 1131, Universitetsparken, DK-8000 Aarhus C, Denmark.

Abstract

Recent evidence suggests that the reaction of nitrite with deoxygenated hemoglobin and myoglobin contributes to the generation of nitric oxide and S-nitrosothiols in vivo under conditions of low oxygen availability. We have investigated whether ferrous neuroglobin and cytoglobin, the two hexacoordinate globins from vertebrates expressed in brain and in a variety of tissues, respectively, also react with nitrite under anaerobic conditions. Using absorption spectroscopy, we find that ferrous neuroglobin and nitrite react with a second-order rate constant similar to that of myoglobin, whereas the ferrous heme of cytoglobin does not react with nitrite. Deconvolution of absorbance spectra shows that, in the course of the reaction of neuroglobin with nitrite, ferric Fe(III) heme is generated in excess of nitrosyl Fe(II)-NO heme as due to the low affinity of ferrous neuroglobin for nitric oxide. By using ferrous myoglobin as scavenger for nitric oxide, we find that nitric oxide dissociates from ferrous neuroglobin much faster than previously appreciated, consistently with the decay of the Fe(II)-NO product during the reaction. Both neuroglobin and cytoglobin are S-nitrosated when reacting with nitrite, with neuroglobin showing higher levels of S-nitrosation. The possible biological significance of the reaction between nitrite and neuroglobin in vivo under brain hypoxia is discussed.

PMID:
18599123
DOI:
10.1016/j.jinorgbio.2008.05.008
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center