Direct evidence of caeruloplasmin antioxidant properties

Roxana L. Atanasiu, Baldassarre Stea, Mircea A. Mateescu, Catherine Vergely, Florence Dalloz, François Briot, Véronique Maupoil, Réginald Nadeau, Luc Rochette

Research output: Contribution to journalArticle

83 Scopus citations

Abstract

The chain-breaking antioxidant potential of caeruloplasmin and bovine serum albumin (BSA) has been investigated in comparison with other well-established antioxidants. Their Oxygen Radical Absorbing Capacity (ORAC), was measured by using β-phycocyanin (β-PC) as a fluorescent indicator protein, 2,2'-azobis (2-amidinopropane) hydrochloride (AAPH) as a peroxyl radical generator and the water soluble vitamin E analogue, Trolox, as a reference standard. The relative peroxyl absorbing capacities/mole for Trolox, caeruloplasmin, heat-denatured caeruloplasmin (hCP), catalase, bovine serum albumin (BSA), superoxide dismutase (SOD), and deferoxamine were 1; 2.6; 3.3; 3.7; 1.2, 0.1, 0.2, respectively. Caeruloplasmin was far more effective as a peroxyl radical scavenger than SOD, deferoxamine and BSA, but slightly less effective than catalase. The peroxyl radical absorbing capacity of caeruloplasmin was enhanced by heat-denaturation of the protein. Electron paramagnetic resonance (EPR) spectroscopy using 5,5-dimethyl-l-pyrroline N-oxide (DMPO) as a spin-trap, was applied in order to measure the scavenger abilities of caeruloplasmin on superoxide radical and hydroxyl radical production and the concentration required to inhibit by 50% oxygen free radical formation (IC50) was determined. The IC50 values of caeruloplasmin, hCP, and BSA for the superoxide radical were 12, 2, 260 μM and for the hydroxyl radical 15, 2, 200 μM. These results show that caeruloplasmin is an effective chain-breaking antioxidant for a variety of radicals, independently of its catalytic ferroxidase activity.

Original languageEnglish (US)
Pages (from-to)127-135
Number of pages9
JournalMolecular and Cellular Biochemistry
Volume189
Issue number1-2
Publication statusPublished - 1998
Externally publishedYes

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Keywords

  • Antioxidants
  • Caeruloplasmin
  • Electron paramagnetic resonance (EPR)
  • Oxygen Radical Absorbing Capacity (ORAC)
  • Proteins

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

Cite this

Atanasiu, R. L., Stea, B., Mateescu, M. A., Vergely, C., Dalloz, F., Briot, F., ... Rochette, L. (1998). Direct evidence of caeruloplasmin antioxidant properties. Molecular and Cellular Biochemistry, 189(1-2), 127-135.