Back to Search
Start Over
Studies on the enzymatic reduction of C-nitroso compounds. III. The kinetic analysis of C-nitrosoreductase reaction catalyzed by the cytoplasmic enzyme from porcine liver.
- Source :
-
Journal of biochemistry [J Biochem] 1980 Oct; Vol. 88 (4), pp. 1135-9. - Publication Year :
- 1980
-
Abstract
- The reaction kinetics of the major cytoplasmic NADH-nitrosoreductase, which is the identical enzyme to alcohol dehydrogenase [EC 1.1.1.1], was studied with a partially purified preparation from porcine liver. On the basis of the data obtained, the following scheme is proposed as the mechanism of this enzyme reaction: [Formula: see text], where E and E' are the enzyme unit (one subunit of alcohol dehydrogenase) and an intermediate form of the enzyme unit-substrate compound which appears by two-electron reduction of the enzyme unit-substrate compound, respectively, S is p-nitrosophenol (p-NSP), N is NADH, and P1 and P2 are NAD+ and p-aminophenol (p-AmP), respectively. In this case, it is assumed that k1 less than K2. Para-aminophenol, the reaction product, showed an inhibition competitive to p-NSP at fixed concentrations of NADH and also showed a mixed-type inhibition to NADH at fixed concentrations of p-NSP. NAD+ inhibited the reaction in a competitive manner to NADH at fixed concentrations of p-NSP and in a non-competitive manner to p-NSP at fixed concentrations of NADH. These results can also be accounted for by the proposed mechanism.
Details
- Language :
- English
- ISSN :
- 0021-924X
- Volume :
- 88
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Journal of biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 7005209
- Full Text :
- https://doi.org/10.1093/oxfordjournals.jbchem.a133067