Paraquat toxicity and pyridine nucleotide coenzyme synthesis: a data correction.

Abstract

The decrease in pyridine nucleotide coenzymes which occurs during poisoning of Escherichia coli by hyperbaric oxygen or paraquat is not due to impairment of nicotinatemononucleotide pyrophosphorylase (carboxylating) [EC 2.4.2.19] as was previously proposed (Brown, O.R. et al. Biochem. Biophys. Res. Commun. 91:982-990; 1979). This was shown directly using extracts of E. coli, prepared after exposure to 1 mM paraquat or 4.2 atmospheres of oxygen. The enzyme also was not impaired in Neurospora crassa by 1 mM paraquat. A naturally-occurring, non-dialyzable inhibitor of the enzyme was found in E. coli extracts. The inhibitor caused the erroneous, low nicotinatemononucleotide pyrophosphorylase (carboxylating) activities previously reported in extracts of E. coli poisoned by paraquat.

• Authors: O R Brown, R L Seither
• Journal: Free radical biology & medicine (Free Radic Biol Med) Vol. 8 Issue 2 Pg. 113-6 ( 1990) ISSN: 0891-5849 [Print] United States
• PMID: 2139629 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Coenzymes
• Nucleotides
• Pyridines
• Pentosyltransferases
• nicotinate-nucleotide diphosphorylase (carboxylating)
• Paraquat

Topics

• Coenzymes (biosynthesis)
• Escherichia coli (enzymology)
• Hyperbaric Oxygenation
• Neurospora crassa (enzymology)
• Nucleotides (metabolism)
• Paraquat (toxicity)
• Pentosyltransferases (metabolism)
• Pyridines (metabolism)