Peroxidase eosinophil

Brennan M-L and et al. (2002) A tale of two controversies. Defining both the role of peroxidases in nitrotyro-sine formation in vivo using eosinophil peroxidase and myeloperoxidase-deficient mice, and the natnre of the peroxidase-generated reactive nitrogen species. J Biol Chem 277 17415-17427. 

EPA Eicosapentaenoic acid EpDIF Epithelial-derived inhibitory factor also known as epithelium/derived relaxant fector EPO Eosinophil peroxidase EPOR Erythropoietin receptor EPR Effector cell protease EPX Eosinophil protein X ER Endoplasmic reticulum ERCP Endoscopic retrograde cholangiopancreatography E-selectin Endothelial selectin formerly known as endothelial leucocyte adhesion molecule-1 (ELAM-1)... 

Figure 4 Stabilized bromine antimicrobials are produced by eosinophils, a type of mammalian white blood cell. Bacteria are captured by phagocytosis and contained intracellularly within vesicles called phagosomes. Granules release cationic surfactants, lytic enzymes, and eosinophil peroxidase into the phagosome in a process known as degranulation. Eosinophil peroxidase, an enzyme that is structurally similar to the bromoperoxidases found in seaweed (Figure I), selectively catalyzes oxidation of bromide to hypobromite by reducing hydrogen peroxide to water. The hypobromite immediately reacts with nitrogenous stabilizers such as aminoethanesulfonic acid (taurine) to form more effective and less toxic antimicrobial agents.

Nitric oxide and nitrite react with other peroxidase enzymes such as horseradish peroxidase (HRP) (138a,139), lactoperoxidase (138a) and eosinophil peroxidase (140) similarly. The rate constants for reaction of NO with compounds I and II in HRP were found to be 7.0 x 105M 1s 1 and 1.3 x 106M 1s 1, respectively (139). Catalytic consumption of NO as measured by an NO sensitive electrode in the presence of HRP compounds I and II is shown in Fig. 5 where accelerated consumption of NO is achieved even in deoxygenated solutions (140). 

Henderson WR, Jr. Eosinophil peroxidase occurrence and biological function. In Everse J, Everse KE, Grisham MB, eds. Peroxidases in Chemistry and Biology. Boca Raton, FL CRC Press 1991. 

A. Shvedova, B. Fadeel, V. E. Kagan, Biodegradation of carbon nanotubes by eosinophil peroxidase, Toxicology Letters, vol. 211, pp. S204-S204, 2012. 

LTB4). At these infectious sites, eosinophils are activated by Type 2 cytokines released from a specific subset of helper T cells (Th2) thus IL-5, GM-CSF, and IL-3 are important for eosinophil activation as well as maturation. Following activation, eosinophils release the contents of small granules within the cellular cytoplasm, which contain many chemical mediators, such as histamine and proteins such as eosinophil peroxidase, RNase, DNases, lipase, plasminogen, and major basic protein that are toxic to both parasite and host tissues (Gleich and Adolphson 1986). 

In contrast to MPO, eosinophil peroxidase (EPO) prefers to oxidize plasma level bromide (20-100 pM) to hypobromous acid (HOBr) and several biological targets are implicated, including nucleic acids and nucleosides (1480, 1482, 2376), proteins (1812, 1813, 2377, 2378), unsaturated fatty acids (2379), and low-density lipoprotein (2380, 2381). This EPO-dependent bromination is suggested to be involved in the pathogenesis of asthma (2382). Accordingly, both 3-bromotyrosine and 3,5-dibromotyrosine (1812,1813) are produced by EPO-induced bromination of tyrosine residues in lung tissue (1813, 2382). 

Henderson JP, Heinecke JW (2003) Myeloperoxidase and Eosinophil Peroxidase Phagocyte Enzymes for Halogenation in Humans. In Gribble GW (ed) Natural Production of Organohalogen Compounds, The Handbook of Environmental Chemistry, vol 3, part P. Springer, Berlin, p 201... 

Henderson JP, Byun J, Mueller DM, Heinecke JW (2001) The Eosinophil Peroxidase-Hydrogen Peroxide-Bromide System of Human Eosinophils Generates 5-Bromouracil, a Mutagenic Thymine Analogue. Biochemistry 40 2052... 

Wu W, Chen Y, d Avignon A, Hazen SL (1999) 3-Bromotyrosine and 3,5-Dibromotyrosine Are Major Products of Protein Oxidation by Eosinophil Peroxidase Potential Markers for Eosinophil-Dependent Tissue Injury in Vivo. Biochemistry 38 3538... 

Shen Z, Mitra SN, Wu W, Chen Y, Yang Y, Qin J, Hazen SL (2001) Eosinophil Peroxidase Catalyzes Bromination of Free Nucleosides and Double-Stranded DNA. Biochemistry 40 2041... 

EPO—eosinophil peroxidase ESI—electrospray ionization EU—European Union FA—food allergy... 

Fig. 2.7 Detail of the reconstructed phylogenetic tree showing the subfamily of vertebrate peroxidases including the mammalian enzymes myeloperoxidase (MPO), eosinophil peroxidase (EPO), lactoperoxidase (LPO), and thyroid peroxidase (TPO). Reproduced from [10] with the permission of John Wiley and Sons (License Nr. 2326000554179)...

Wang J, Slungaard A (2006) Role of eosinophil peroxidase in host defense and disease pathology. Arch Biochem Biophys 445 256-260... 

The two-electron reduction of Compound I to Fe(III) and the one electron reduction of Compound I to Compound II and Compound II to Fe(III) have been estimated by different methods. These methods will be described in the next section, but they differ in the strategy to estimate the redox potential. Two of them rely on spectral determination of equilibrium between redox species [63-65], whereas a third one proposes the use of catalytic measurements [53]. The values obtained with the different methods are shown in Table 4.4. It should be noted these are not standard values. As expected, one of the more oxidant enzymes is the versatile peroxidase, which is able to catalyze the oxidation of Mn(II) to Mn (III) ( 0,=1.5 V). MPO has the highest two-electron redox potential, supporting the fact that only this enzyme is able to catalyze the oxidation of chloride to hypochlorite at neutral pH [72, 73], whereas eosinophil peroxidase performs better at acidic pH [74]. 

Battistuzzi G, Bellei M, Vlasits J et al (2010) Redox thermodynamics of lactoperoxidase and eosinophil peroxidase. Arch Biochem Biophys 494 72-77... 

Amhold J, Furtmuller PG, Regelsberger G et al (2001) Redox properties of the couple compound I/native enzyme of myeloperoxidase and eosinophil peroxidase. Eur J Biochem 268 5142-5148... 

Oxvig C, Thomsen A, Overgaard M et al (1999) Biochemical evidence for heme linkage through esters with Asp-93 and Glu-241 in human eosinophil peroxidase. The ester with Asp-93 is only partially formed in vivo. J Biol Chem 274 16953-16958... 

Furtmiiller PG, Burner U, Regelsberger G et al (2000) Spectral and kinetic studies on the formation of eosinophil peroxidase compound I and its reactions with halides and thiocyanate. Biochemistry 39 15578-15584... 

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