The free radical formed during the hydroperoxide-mediated deactivation of ram seminal vesicles is hemoprotein-derived. J Biol Chem 1982 May 10;257(9):4764-8
Date
05/10/1982Pubmed ID
6279648Scopus ID
2-s2.0-0020479052 (requires institutional sign-in at Scopus site) 55 CitationsAbstract
Prostaglandin synthase is a multi-enzyme complex which catalyzes the oxygenation of arachidonic acid to the various prostaglandins. During the oxygenation, the enzyme is self-deactivated and, on the basis of ESR data, it has been proposed to form a self-destructive free radical. The free radical was suggested to form from the oxygen lost from prostaglandin G2 during its reduction to prostaglandin H2, and the destructive species was therefore thought to be an oxygen-centered free radical, tentatively identified as the hydroxy radical. We have reinvestigated this ESR signal (g = 2.005) and have concluded, with the aid of the known ESR parameters for the hydroxy and other oxygen-centered free radicals, that the free radical formed during the oxygenation is neither a hydroxy nor any known oxygen-centred radical. Prostaglandin synthase is thought to be a hemoprotein, so this unknown ESR signal was compared with the previously observed free radical formed by the reaction of H2O2 with methemoglobin. This comparison indicates that the free radical formed by the reaction of prostaglandin G2 with ram seminal vesicles is hemoprotein-derived and may be formed by the oxidation of an amino acid(s) located near the iron of the heme.
Author List
Kalyanaraman B, Mason RP, Tainer B, Eling TEAuthor
Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsArachidonic Acid
Arachidonic Acids
Electron Spin Resonance Spectroscopy
Free Radicals
Hemeproteins
Kinetics
Male
Methemoglobin
Metmyoglobin
Oxygen Consumption
Peroxides
Seminal Vesicles
Sheep
