Superoxide anion radical generation during the oxidation of various amines by diamine oxidase.
Free Radic Res
; 24(3): 167-75, 1996 Mar.
Article
in En
| MEDLINE
| ID: mdl-8728118
ABSTRACT
Diamine oxidase (DAO) or histaminase is an enzyme which deaminates histamine and several aliphatic amines to their corresponding aldehydes. Hydrogen peroxide and ammonia are side products of this reaction. The purpose of the present work was to evaluate if determination of produced hydrogen peroxide reflects DAO activity or if intermediate formation of the superoxide radical could be a reason for lack of correspondence between oxygen uptake and hydrogen peroxide production at different pH. Superoxide radical formation was determined by cytochrome c reduction in the presence and absence of superoxide dismutase (SOD). Oxygen uptake was measured with an oxygen electrode and hydrogen peroxide production by a spectrophotometric method. At pH 6.6 there was no superoxide production, but at pH 7.4 there was some, and it increased markedly at pH 9.5. Oxygen uptake also increased with increasing pH, especially with histamine as substrate. These results lead us to suggest that the mechanism of action of DAO involves the intermediate generation of superoxide radicals.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Amine Oxidase (Copper-Containing)
/
Superoxides
/
Amines
Limits:
Animals
Language:
En
Journal:
Free Radic Res
Year:
1996
Document type:
Article