S-Nitrosoglutathione is a substrate for rat alcohol dehydrogenase class III isoenzyme.
In: The Biochemical journal, Jg. 331 ( Pt 2) (1998-04-15), S. 659
academicJournal
Zugriff:
An enzyme isolated from rat liver cytosol (native molecular mass 78. 3 kDa; polypeptide molecular mass 42.5 kDa) is capable of catalysing the NADH/NADPH-dependent degradation of S-nitrosoglutathione (GSNO). The activity utilizes 1 mol of coenzyme per mol of GSNO processed. The isolated enzyme has, as well, several characteristics that are unique to alcohol dehydrogenase (ADH) class III isoenzyme: it is capable of catalysing the NAD+-dependent oxidations of octanol (insensitive to inhibition by 4-methylpyrazole), methylcrotyl alcohol (stimulated by added pentanoate) and 12-hydroxydodecanoic acid, and also the NADH/NADPH-dependent reduction of octanal. Methanol and ethanol oxidation activity is minimal. The enzyme has formaldehyde dehydrogenase activity in that it is capable of catalysing the NAD+/NADP+-dependent oxidation of S-hydroxymethylglutathione. Treatment with the arginine-specific reagent phenylglyoxal prevents the pentanoate stimulation of methylcrotyl alcohol oxidation and markedly diminishes the enzymic activity towards octanol, 12-hydroxydodecanoic acid and S-hydroxymethylglutathione; the capacity to catalyse GSNO degradation is also checked. Additionally, limited peptide sequencing indicates 100% correspondence with known ADH class III isoenzyme sequences. Kinetic studies demonstrate that GSNO is an exceptionally active substrate for this enzyme. S-Nitroso-N-acetylpenicillamine and S-nitrosated human serum albumin are not substrates; the activity towards S-nitrosated glutathione mono- and di-ethyl esters is minimal. Product analysis suggests that glutathione sulphinamide is the major stable product of enzymic GSNO processing, with minor yields of GSSG and NH3; GSH, hydroxylamine, nitrite, nitrate and nitric oxide accumulations are minimal. Inclusion of GSH in the reaction mix decreases the yield of the supposed glutathione sulphinamide in favor of GSSG and hydroxylamine.
Titel: |
S-Nitrosoglutathione is a substrate for rat alcohol dehydrogenase class III isoenzyme.
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Autor/in / Beteiligte Person: | Jensen, DE ; Belka, GK ; Du Bois, GC |
Zeitschrift: | The Biochemical journal, Jg. 331 ( Pt 2) (1998-04-15), S. 659 |
Veröffentlichung: | London, UK : Published by Portland Press on behalf of the Biochemical Society, 1998 |
Medientyp: | academicJournal |
ISSN: | 0264-6021 (print) |
DOI: | 10.1042/bj3310659 |
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