Home General Physiology and Biophysics 2009 General Physiology and Biophysics Vol.28, No.4, p.384–390, 2009

Journal info

Quarterly, 80 pp. per issue
Founded: 1982
ISSN  1338-4325 (online)

Published in English

Aims and Scope
Editorial Info
Abstracting and Indexing
Submission Guidelines

Select Journal

Webshop Cart

Your Cart is currently empty.

Info: Your browser does not accept cookies. To put products into your cart and purchase them you need to enable cookies.

General Physiology and Biophysics Vol.28, No.4, p.384–390, 2009

Title: Lipoamide dehydrogenase and diaphorase catalyzed conversion of some NO donors to NO and reduction of NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO)
Author: Alena Stibingerová, Hana Velvarská, Klára Kynčlová, Běla Marounková, Marcela Špundová and Gustav Entlicher

Abstract: One of the key functions of nitric oxide (NO) in human is to dilate blood vessels. We tested glycerol trinitrate (GTN) and other well-known NO donors together with those bearing a >C=N-OH group for possible conversion to NO (or nitrites, respectively) by diaphorase (DP) and lipoamide dehydrogenase (LAD). Both, DP and LAD were unable to convert formamidoxime (FAM), acetone oxime (AC), acetohydroxamic acid (AHA) and Nω-hydroxy-L-arginine (L-NOHA). On the other hand, we observed good conversion of GTN without the requirement of superoxide anion. However, superoxide anion participated to a varying extent in the conversion of other donors (formaldoxime (FAL), acetaldoxime (AO), nitroprusside (NP), S-nitrosoglutathione (SNOG), S-nitroso-N-acetylpenicillamine (SNAP) and hydroxylamine (HA)). All DP- and LAD-mediated reactions were inhibited by diphenyleneiodonium chloride (DPI), (an inhibitor of flavine enzymes), in a concentration-dependent manner. For these inhibition reactions we determined Ki and IC50 values. In addition, we found that conversion of SNOG was significantly accelerated by glutathione reductase (GTR). Like with DP, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) was reduced also by LAD and thioredoxin reductase (TRR). In summary, we found that LAD significantly accelerates the conversion of a defined subset of NO donors to NO, especially GTN, and eliminates the NO scavenging effect of PTIO.

Keywords: Lipoamide dehydrogenase — Diaphorase — Glutathione reductase — NO donors — PTIO
Year: 2009, Volume: 28, Issue: 4 Page From: 384, Page To: 390

download file

© AEPress s.r.o
Copyright notice: For any permission to reproduce, archive or otherwise use the documents in the ELiS, please contact AEP.