On the haemoprotein character of prostaglandin endoperoxide synthetase
| Autor: | F.J. Van Der Ouderaa, F.J. Slikkerveer, M. Buytenhek, D.A. Van Dorp |
|---|---|
| Rok vydání: | 1979 |
| Předmět: |
Hemeproteins
Male Molar concentration Hemeprotein Stereochemistry Iron Dimer Biophysics Biochemistry chemistry.chemical_compound Endocrinology Animals Molecule chemistry.chemical_classification Cyanides Sheep biology Dithionite Seminal Vesicles Molecular Weight Enzyme Peroxidases chemistry Prostaglandin-Endoperoxide Synthases Oxygenases biology.protein Hemin Cyclooxygenase Glycoprotein Protein Binding Peroxidase |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 572:29-42 |
| ISSN: | 0005-2760 |
| DOI: | 10.1016/0005-2760(79)90197-8 |
| Popis: | Prostaglandin endoperoxide synthetase is a membrane-bound glycoprotein isolated as a dimer of molecular weight of approximately 129 000 consisting of two identical polypeptide chains. Several research workers have reported that haemin (ferri-protoporphyrin-IX) is required to restore the full enzymic activity of the pure apoprotein. Difference spectroscopy shows association of haemin up to two molecules per polypeptide chain of molecular weight 70 000. Both the cyclooxygenase and the peroxidase activity displayed by the enzyme can be optimally stimulated by similar quantities of haemin. The restored haemin-enzyme complex has a millimolar absorption coefficient at 408 nm of 61 mM−1 · cm−1 per haem. Using this value, the presence of non-haem iron in the enzyme is virtually excluded. These findings and the spectra of the reassociated enzyme-haemin complex point to a haemoprotein character. The availability of haemin to the enzyme might play a regulating role in its action. |
| Databáze: | OpenAIRE |
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