Chlorination by the Myeloperoxidase-H2O2-CI-Antimicrobial System at Acid and Neutral pH

Zgliczyński, J.M.; Selvaraj, Ratnam J.; Paul, B. B.; Stelmaszyńska, Teresa; Poskitt, Paula K. F.; Sbarra, Anthony J.

doi:10.3181/00379727-154-39684

Cited by 80 publications

(44 citation statements)

References 3 publications

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“…The H202-myeloperoxidase-Cl-system is capable of generating the powerful oxidant hypochlorous acid (HOCG) (22)(23)(24). HOCG is known to react rapidly with amines, amides, or sulfhydryl groups and can destroy a variety of biological targets including bacteria and tumor cells (5,8,25,26).…”

Section: Resultsmentioning

confidence: 99%

Role of hydrogen peroxide in neutrophil-mediated destruction of cultured endothelial cells.

Weiss¹,

Young²,

LoBuglio³

et al. 1981

J. Clin. Invest.

536

193

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Section: Resultsmentioning

confidence: 99%

Role of hydrogen peroxide in neutrophil-mediated destruction of cultured endothelial cells.

Weiss¹,

Young²,

LoBuglio³

et al. 1981

J. Clin. Invest.

536

193

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“…The only modification was that hydrogen peroxide, the reaction-starting substrate, was added step-by-step in successive portions at a concentration causing optimal chlorination [23]. The addition of H202 in multiple steps allowed its optimal concentration to be maintained and made it possible to chlorinate any amount of amine, within a broad pH range and AcAla (----) was followed by an increase in absorbance at 264nm (-o),…”

Section: Chlorination Of Dipep-ptides By the Myeloperoxidaselh~02/cl-mentioning

confidence: 99%

N‐(2‐Oxoacyl)amino Acids and Nitriles as Final Products of Dipeptide Chlorination Mediated by the Myeloperoxidase/H₂O₂/Cl⁻ System

Stelmaszyńska¹,

Zgliczyński²

1978

European Journal of Biochemistry

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The chlorination of dipeptides by the myeloperoxidase/H20~/C1-system takes place at the N-terminal amino group, whereas no chlorination of the amide nitrogen of the peptide bond can be observed. The N-terminal amino group is chlorinated to N-monochloroamine or/and N-dichloroamine. N-Monochloropeptides were the main products at higher pH values, at lower pH a mixture of N-monochloropeptides and N-dichloropeptides was formed owing to the dismutation of N-monochloroamine to N-dichloroamine.N-Monochloropeptides decompose, yielding NH3 and the corresponding N-(2-oxoacyl)amino acids. N-Dichlorodipeptides decompose faster but to nitriles and the free C-terminal amino acids. N-Dichloroglycyl-amino acid decomposes through a relatively stable intermediate (cyano-formylamino acid) to hydrogen cyanide, cyanogen chloride and the free C-terminal amino acid. lnsulin chlorination also yields N-terminal glycyl and phenylalanyl N-monochloro derivatives, which deaminate to glyoxylyl and phenylpyruvyl residues.Myeloperoxidase of polymorphonuclear neutrophilic granulocytes catalyses the oxidation of CIions to HOCl by hydrogen peroxide [1-31. The chlorinating ability of myeloperoxidase seems to be important for the bactericidal mechanisms of neutrophils [4-61. The physiological role of the chlorination process was emphasized by its discovery in granulocytes undergoing phagocytosis [7]. Peptides and proteins may be target substrates for chlorination during phagocytosis. The incorporation of 36Cl into bovine albumin by purified myeloperoxidase was reported [7].From the chemical point of view, many different functional groups in protein are susceptible to HOCl attack : e.g. amino, imidazolium, guanidinium, indole residues, phenolic rings and the amide nitrogen of peptide bonds. In the enzymatic reaction, however, HOCl production by myeloperoxidase is impaired when the chlorination or oxidation of the HOClreactive substrate is slower than that of the enzyme itself. In such cases autodestruction of niyeloperoxidase occurs.Abbreviations. AcAla, N-acetyl-alanine; CIGly-Leu, N-monochloroglycyl-leucine; CIAla-Ala, N-monochloroalanyl-aianine; ClLeu-Gly, N-monochloroleucyl-glycine; ClzCly-Leu, N-dichloroglycyl-leucine.Enzyme. Myeloperoxidase (EC 1.11.1.7).It was established that amino compounds are effective acceptors of C1' ions formed in myeloperoxidase-mediated reactions [2,8] and protect myeloperoxidase against HOCl attack [9].Preliminary examination of bovine albumin chlorination by the myeloperoxidase system showed that 36Cl incorporated into protein was to a great extent K1-reactive, i.e. N-CI bonds were formed. These results focussed attention on the chlorination of the protein amino groups (N-terminal and 8-lysine amino groups) and the amide nitrogen of peptide bonds.It seemed reasonable to start the systematic elucidation of protein chlorination by examining the reactions of simple dipeptides without side-chain functional residues. This made it possible to check the reactions only of N-terminal amino groups and of the peptidebond ami...

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“…Stimulated PMNs release the heme protein myeloperoxidase (MPO) that is able to oxidise (pseudo)halides to the corresponding (pseudo)hypohalous acids in the presence of hydrogen peroxide as well as a large number of small molecules under formation of radicals [7][8][9][10][11]. It has been assumed that myeloperoxidase contributes with these reactive species to the killing of foreign microorganisms [12,13] and also to tissue damage under inflammatory conditions [14,15].…”

Section: Introductionmentioning

confidence: 99%

Myeloperoxidase binds to non-vital spermatozoa on phosphatidylserine epitopes

et al. 2007

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The heme protein myeloperoxidase is released from stimulated polymorphonuclear leukocytes, a cell species found in increasing amounts in the male and female genital tract of patients with genital tract inflammations. Myeloperoxidase binds only to a fraction of freshly prepared human spermatozoa. The number of spermatozoa able to bind myeloperoxidase raised considerably in samples containing pre-damaged cells or in acrosome-reacted samples. In addition, myeloperoxidase released from zymosan-stimulated polymorphonuclear leukocytes was also able to bind to pre-damaged spermatozoa. The ability of spermatozoa to bind myeloperoxidase coincided with the binding of annexin V to externalized phosphatidylserine epitopes indicating the loss of plasma membrane integrity and with the incorporation of ethidium homodimer I. Myeloperoxidase did not interact with intact spermatozoa. Annexin V and myeloperoxidase bind to the same binding sites as verified by double fluorescence techniques, flowcytometry analyses as well as competition experiments. We demonstrated also that myeloperoxidase is eluted together with pure phosphatidylserine liposomes or liposomes composed of phosphatidylserine and phosphatidylcholine in gel filtration, but not with pure phosphatidylcholine liposomes. In conclusion, myeloperoxidase interacts with apoptotic spermatozoa via binding to externalized phosphatidylserine indicating a yet unknown role of this protein in recognition and removal of apoptotic cells during inflammation.

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Chlorination by the Myeloperoxidase-H2O2-CI-Antimicrobial System at Acid and Neutral pH

Cited by 80 publications

References 3 publications

Role of hydrogen peroxide in neutrophil-mediated destruction of cultured endothelial cells.

Role of hydrogen peroxide in neutrophil-mediated destruction of cultured endothelial cells.

N‐(2‐Oxoacyl)amino Acids and Nitriles as Final Products of Dipeptide Chlorination Mediated by the Myeloperoxidase/H₂O₂/Cl⁻ System

Myeloperoxidase binds to non-vital spermatozoa on phosphatidylserine epitopes

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Chlorination by the Myeloperoxidase-H2O2-CI-Antimicrobial System at Acid and Neutral pH

Cited by 80 publications

References 3 publications

Role of hydrogen peroxide in neutrophil-mediated destruction of cultured endothelial cells.

Role of hydrogen peroxide in neutrophil-mediated destruction of cultured endothelial cells.

N‐(2‐Oxoacyl)amino Acids and Nitriles as Final Products of Dipeptide Chlorination Mediated by the Myeloperoxidase/H2O2/Cl− System

Myeloperoxidase binds to non-vital spermatozoa on phosphatidylserine epitopes

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N‐(2‐Oxoacyl)amino Acids and Nitriles as Final Products of Dipeptide Chlorination Mediated by the Myeloperoxidase/H₂O₂/Cl⁻ System