L-Dopa peroxidase activity of human erythrocyte catalase.
1977; National Institutes of Health; Volume: 89; Issue: 4 Linguagem: Inglês
Autores
Sanjay Awasthi, Satish K. Srivastava, L. Michael Snyder, L. Edelstein, Normand L. Fortier,
Tópico(s)Biochemical Acid Research Studies
ResumoThe human red cell hemolysate was found to have 3-(3',4'-dihydroxphenyl)-L-alanine (L-dopa) peroxidase activity. During the purification of glutathione peroxidase and catalase by ammonium sulfate precipitation, ion exchange chromatography. Sephadex gel filtration, and preparative polyacrylamide disc electrophoresis, the L-dopa peroxidase activity was found to be associated with catalase. Both sodium azide, 8 mM, and 3-amino-1,2,4-triazole, 50 mM, besides inhibiting catalase, inhibited the L-dopa peroxidase activity in each fraction. Ethylenediamine tetraacetic acid (EDTA), 4 mM, had no effect on catalase or L-dopa peroxidase activity, indicating that the oxidation of L-dopa is not a nonenzymatic process mediated by metal ions. Although the electrophoretic mobility of catalase, L-dopa peroxidase, and glutathione peroxidase are similar, a homogeneous preparation of glutathione peroxidase was free of L-dopa peroxidase activity. L-Dopa peroxidase in human red cells was co-purified with catalase.
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