ArticleFree radical biology & medicine2008
Potential role of tryptophan and chloride in the inhibition of human myeloperoxidase.
Article in Free radical biology & medicine, 2008. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
15 citing papers in PubMed, 38 citations in OpenAlex.
- Peroxidase-Catalyzed and Photo-Oxidation of Tryptophan Results in Distinct Isomeric Tryptophan Dimers.ACS omega · 2025Article
- Targeting Myeloperoxidase Ameliorates Gouty Arthritis: A Virtual Screening Success Story.Journal of medicinal chemistry · 2024Article
- Characterization of Myeloperoxidase in the Healthy Equine Endometrium.Animals : an open access journal from MDPI · 2023Article
- Melatonin interferes with COVID-19 at several distinct ROS-related steps.Journal of inorganic biochemistry · 2021Review
- A Multiple-Hit Hypothesis Involving Reactive Oxygen Species and Myeloperoxidase Explains Clinical Deterioration and Fatality in COVID-19.International journal of biological sciences · 2021Review
- Mesna (2-mercaptoethane sodium sulfonate) functions as a regulator of myeloperoxidase.Free radical biology & medicine · 2017Article
- Melatonin prevents myeloperoxidase heme destruction and the generation of free iron mediated by self-generated hypochlorous acid.PloS one · 2015Article
- Myeloperoxidase acts as a source of free iron during steady-state catalysis by a feedback inhibitory pathway.Free radical biology & medicine · 2013Article
- Human indoleamine 2,3-dioxygenase is a catalyst of physiological heme peroxidase reactions: implications for the inhibition of dioxygenase activity by hydrogen peroxide.The Journal of biological chemistry · 2013Article
- The reaction of HOCl and cyanocobalamin: corrin destruction and the liberation of cyanogen chloride.Free radical biology & medicine · 2012Article
- Reaction of hemoglobin with HOCl: mechanism of heme destruction and free iron release.Free radical biology & medicine · 2011Article
- Mechanism of hypochlorous acid-mediated heme destruction and free iron release.Free radical biology & medicine · 2011Article
- Myeloperoxidase-derived oxidation: mechanisms of biological damage and its prevention.Journal of clinical biochemistry and nutrition · 2011Article
- Potent antioxidative activity of lycopene: A potential role in scavenging hypochlorous acid.Free radical biology & medicine · 2010Article
- Myeloperoxidase interaction with peroxynitrite: chloride deficiency and heme depletion.Free radical biology & medicine · 2009Article
Corrections and comments
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Authors and funding
3 authors at 2 institutions in 1 country.
Funding
Abstract
Myeloperoxidase (MPO) binds H2O2 in the absence and presence of chloride (Cl-) and catalyzes the formation of potent oxidants through 1e(-) and 2e(-) oxidation pathways. These potent oxidants have been implicated in the pathogenesis of various diseases including atherosclerosis, asthma, arthritis, and cancer. Thus, inhibition of MPO and its by-products may have a wide application in biological systems. Using direct rapid kinetic measurements and H2O2-selective electrodes, we show that tryptophan (Trp), an essential amino acid, is linked kinetically to the inhibition of MPO catalysis under physiological conditions. Trp inactivated MPO in the absence and presence of plasma levels of Cl(-), to various degrees, through binding to MPO, forming the inactive complexes Trp-MPO and Trp-MPO-Cl, and accelerating formation of MPO Compound II, an inactive form of MPO. Inactivation of MPO was mirrored by the direct conversion of MPO-Fe(III) to MPO Compound II without any sign of Compound I accumulation. This behavior indicates that Trp binding modulates the formation of MPO intermediates and their decay rates. Importantly, Trp is a poor substrate for MPO Compound II and has no role in destabilizing complex formation. Thus, the overall MPO catalytic activity will be limited by: (1) the dissociation of Trp from Trp-MPO and Trp-MPO-Cl complexes, (2) the affinity of MPO Compound I toward Cl(-) versus Trp, and (3) the slow conversion of MPO Compound II to MPO-Fe(III). Importantly, Trp-dependent inhibition of MPO occurred at a wide range of concentrations that span various physiological and supplemental ranges.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.