Oxidation of cysteine by ceruloplasmin leads to formation of hydrogen peroxide, which can be utilized by myeloperoxidase
- Institute of Experimental Medicine, 197376, Saint-Petersburg (Russian Federation)
Highlights: • Ceruloplasmin oxidizes cysteine with formation of hydrogen peroxide. • Key role in oxidation of cysteine belongs to labile copper ions in ceruloplasmin. • Myeloperoxidase may use hydrogen peroxide produced by ceruloplasmin in the presence of tyrosine at neutral pH. Myeloperoxidase (MPO) is the enzyme of azurophilic granules of neutrophils, which catalyzes two electron oxidation of either chloride or bromide in the so-called “halogenating cycle”. Interaction of hydrogen peroxide with MPO in the presence of chloride ions leads to formation of hypochlorous acid (HOCl). Ceruloplasmin (CP) is known to be an effective physiological inhibitor of the MPO activity. However, despite the large excess of CP in blood plasma, MPO-dependently modified biomolecules were found in variety of inflammation loci, including vessel walls. This study shows that CP, which is supposed to inhibit MPO, can provide its action in physiological conditions due to hydrogen peroxide formation during oxidation of free cysteine. The key role of labile copper ions in said process is also demonstrated.
- OSTI ID:
- 23105564
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 503, Issue 3; Other Information: Copyright (c) 2018 Elsevier Inc. All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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