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Dissociation of nitric oxide from soluble guanylate cyclase.

Authors :
Kharitonov VG
Russwurm M
Magde D
Sharma VS
Koesling D
Source :
Biochemical and biophysical research communications [Biochem Biophys Res Commun] 1997 Oct 09; Vol. 239 (1), pp. 284-6.
Publication Year :
1997

Abstract

Kinetic studies of soluble guanylate cyclase complexed with nitric oxide prove that NO dissociation in the presence of the substrate GTP and Mg2+ is as much as 50 times faster than in their absence. In the presence of those two reagents the dissociation rate constant is k(obs) = 0.04 +/- 0.01 s-1 at 20 degrees C, which is by far the fastest NO dissociation rate constant ever reported for a ferrous heme protein. Extrapolated to 37 degrees C, this corresponds to a half life of about 5 s for NO dissociation from soluble guanylate cyclase at physiological conditions, which is presumably fast enough to account for deactivation of the enzyme in biological systems. Dissociation rate constants are also reported for a variety of other reagent conditions.

Details

Language :
English
ISSN :
0006-291X
Volume :
239
Issue :
1
Database :
MEDLINE
Journal :
Biochemical and biophysical research communications
Publication Type :
Academic Journal
Accession number :
9345311
Full Text :
https://doi.org/10.1006/bbrc.1997.7470