... (myeloperoxidase) in the inflamed artery wall, and smokers have high levels of SCN − , a preferred MPO substrate, with this resulting in HOSCN (hypothiocyanous acid) formation. We hypothesized that this thiol-specific oxidant may target the Zn 2+ –thiol cluster of eNOS (endothelial nitric oxide synthase...

...Katrina A. Hadfield; David I. Pattison; Bronwyn E. Brown; Liming Hou; Kerry-Anne Rye; Michael J. Davies; Clare L. Hawkins Oxidative modification of HDLs (high-density lipoproteins) by MPO (myeloperoxidase) compromises its anti-atherogenic properties, which may contribute to the development...

...Raphael F. Queiroz; Sandra M. Vaz; Ohara Augusto The nitroxide tempol (4-hydroxy-2,2,6,6-tetramethyl piperidine-1-oxyl) reduces tissue injury in animal models of inflammation by mechanisms that are not completely understood. MPO (myeloperoxidase), which plays a fundamental role in oxidant...

...Amanda E. Lane; Joanne T. M. Tan; Clare L. Hawkins; Alison K. Heather; Michael J. Davies MPO (myeloperoxidase) catalyses the oxidation of chloride, bromide and thiocyanate by hydrogen peroxide to HOCl (hypochlorous acid), HOBr (hypobromous acid) and HOSCN (hypothiocyanous acid) respectively...

... myeloperoxidase. Among numerous other mediators, platelets liberate serotonin (5-hydroxytryptamine), which is a classical neurotransmitter and vasoactive amine that has significant effects on inflammation and immunity. In the present study, we show that serotonin is a favoured substrate for myeloperoxidase...

...Ojia Skaff; David I. Pattison; Michael J. Davies MPO (myeloperoxidase) catalyses the oxidation of chloride, bromide and thiocyanate by H 2 O 2 to HOCl (hypochlorous acid), HOBr (hypobromous acid) and HOSCN (hypothiocyanous acid, also know as cyanosulfenic acid) respectively. Specificity constants...

...Martin D. Rees; Steven E. Bottle; Kathryn E. Fairfull-Smith; Ernst Malle; John M. Whitelock; Michael J. Davies Tissue damage resulting from the extracellular production of HOCl (hypochlorous acid) by the MPO (myeloperoxidase)-hydrogen peroxide-chloride system of activated phagocytes is implicated...

...Anna L. P. Chapman; Ojia Skaff; Revathy Senthilmohan; Anthony J. Kettle; Michael J. Davies MPO (myeloperoxidase) catalyses the oxidation of chloride, bromide and thiocyanate to their respective hypohalous acids. We have investigated the generation of HOBr by human neutrophils in the presence...

...Clare L. Hawkins; David I. Pattison; Naomi R. Stanley; Michael J. Davies Myeloperoxidase, released by activated phagocytes, forms reactive oxidants by catalysing the reaction of halide and pseudo-halide ions with H 2 O 2 . These oxidants have been linked to tissue damage in a range of inflammatory...

...Mitchell M. Lloyd; David M. van Reyk; Michael J. Davies; Clare L. Hawkins Hypohalous acids are generated by activated leucocytes, via the formation of H 2 O 2 and the release of peroxidase enzymes (myeloperoxidase and eosinophil peroxidase). These species are important bactericidal agents, but HOCl...

...-lysine and the methylglyoxal-derived products, carboxyethyl-lysine, argpyrimidine and MODIC (methylglyoxal-derived imidazolium cross-link). These results provide support for the presence of metal-catalysed oxidation (the Suyama pathway) in diabetes and the possible activation of myeloperoxidase during...

... characterized. We show that the small GTPase Rab27a is an essential component of the secretory machinery of azurophilic granules in granulocytes. Rab27a-deficient mice have impaired secretion of MPO (myeloperoxidase) into the plasma in response to lipopolysaccharide. Cell fractionation analysis revealed...

...Martin D. Rees; Tane N. McNiven; Michael J. Davies EPO (eosinophil peroxidase) and MPO (myeloperoxidase) are highly basic haem enzymes that can catalyse the production of HOBr (hypobromous acid). They are released extracellularly by activated leucocytes and their binding to the polyanionic glycosa...

...D. Tim Harwood; Anthony J. Kettle; Christine C. Winterbourn GSH is rapidly oxidized by HOCl (hypochlorous acid), which is produced physiologically by the neutrophil enzyme myeloperoxidase. It is converted into, mainly, oxidized glutathione. Glutathione sulfonamide is an additional product...

... of eosinophil peroxidase than with the analogous redox intermediate of myeloperoxidase. Nitration by eosinophils was increased 3-fold by superoxide dismutase, which indicates that superoxide interferes with nitration. We propose that at sites of eosinophilic inflammation, low concentrations of nitrite...

...Martin D. Rees; David I. Pattison; Michael J. Davies Activated phagocytes release the haem enzyme MPO (myeloperoxidase) and produce superoxide radicals and H 2 O 2 via an oxidative burst. MPO uses H 2 O 2 and Cl − to form HOCl, the physiological mixture of hypochlorous acid and its anion present...

...) and its derivative, melatonin. Using the recombinant enzyme expressed in Escherichia coli , we show in the present work that indoleamine 2,3-dioxygenase indeed cleaves tryptophan; however, under the same conditions, it is incapable of cleaving the two other indoleamines. By contrast, myeloperoxidase (EC...

...Martin D. REES; Clare L. HAWKINS; Michael J. DAVIES Activated phagocytes release the haem enzyme MPO (myeloperoxidase) and also generate superoxide radicals (O 2 •− ), and hence H 2 O 2 , via an oxidative burst. Reaction of MPO with H 2 O 2 in the presence of chloride ions generates HOCl...

... for the haem enzyme MPO (myeloperoxidase), released by activated monocytes (and possibly macrophages), in oxidative events within the artery wall. As MPO is released extracellularly, and is highly basic, it might be expected to associate with poly-anionic matrix components thereby localizing damage...

...Anna L. P. CHAPMAN; Christine C. WINTERBOURN; Stephen O. BRENNAN; T. William JORDAN; Anthony J. KETTLE Hypochlorous acid (HOCl) is a potent oxidant produced by myeloperoxidase that causes aggregation of many proteins. Treatment of apohaemoglobin and apomyoglobin with HOCl produced a regular series...

... myeloperoxidase (MPO). As MPO is released extracellularly by activated monocytes (and possibly macrophages) and is a highly basic protein, it would be expected to associate with polyanions such as the glycosaminoglycans of the extracellular matrix, and might result in damage being localized at such sites...

...-stimulated leucocytes. The inhibition of myeloperoxidase activity did not reduce protein nitration; on the other hand, the myeloperoxidase inhibitor aminobenzoic hydrazide caused increased nitration, which was mediated by ONOO - . These results suggest that protein nitration is predominantly mediated...

...Clare L. HAWKINS; David I. PATTISON; Michael J. DAVIES Stimulated phagocyte cells produce the oxidant HOCl, via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl is important in bacterial cell killing, but excessive or misplaced generation can damage the host tissue and may lead...

... and 0.15mM respectively. On the basis of these values thiocyanate is preferred 2.8-fold over bromide as a substrate for eosinophil peroxidase. Eosinophil peroxidase catalysed substantive oxidation of chloride only below pH6.5. We found that when eosinophil peroxidase or myeloperoxidase oxidized thiocyanate...

...Clare L. HAWKINS; Michael J. DAVIES Activated phagocyte cells generate hypochlorite (HOCl) via the release of H 2 O 2 and the enzyme myeloperoxidase. Plasma proteins are major targets for HOCl, although little information is available about the mechanism(s) of oxidation. In this study the reaction...