Protein nitration and nitrosylation have recently emerged as important post-translational modifications of proteins. This review summarizes the current knowledge of nitration of tyrosine residues in proteins and the sources, fates and roles of nitrated proteins in vivo. Tyrosine residues are nitrated to 3-nitrotyrosine residues by reactive compounds like nitric oxide, nitric dioxide, peroxynitrite and nitrite metabolites as well as by other reactive nitrogen and oxygen species. Peroxynitrites are probably the most important nitration agents in vivo, though other nitrations have also been described. The introduced nitro group influences pKa of the tyrosine residue and its accessibility to phosphorylation as well as protein structure, stability and biological activity. The enhanced nitration of proteins is a consequence of a higher production of reactive nitrogen and oxygen species and/or their lower scavenging. Nitratd proteins are observed in many cardiovascular, neurodegenerative and inflammatory pathologies. The nitrated proteins can be detected by immunohistochemical methods in situ or detected and identified by chromatography and mass spectrometry.
- MeSH
- Nitrates metabolism MeSH
- Financing, Organized MeSH
- Mitochondrial Proteins biosynthesis metabolism MeSH
- Neurodegenerative Diseases diagnosis metabolism MeSH
- Nitric Oxide metabolism MeSH
- Reactive Nitrogen Species metabolism MeSH
- Electron Transport Complex I metabolism MeSH
- Tandem Mass Spectrometry methods utilization MeSH
- Tyrosine analogs & derivatives biosynthesis metabolism MeSH
Oxidative stress can lead to various derivatives of the tyrosine residue in peptides and proteins. A typical product is 3-nitro-L-tyrosine residue (Nit), which can affect protein behavior during neurodegenerative processes, such as those associated with Alzheimer's and Parkinson's diseases. Surface enhanced Raman spectroscopy (SERS) is a technique with potential for detecting peptides and their metabolic products at very low concentrations. To explore the applicability to Nit, we use SERS to monitor tyrosine nitration in Met-Enkephalin, rev-Prion protein, and α-synuclein models. Useful nitration indicators were the intensity ratio of two tyrosine marker bands at 825 and 870 cm-1 and a bending vibration of the nitro group. During the SERS measurement, a conversion of nitrotyrosine to azobenzene containing peptides was observed. The interpretation of the spectra has been based on density functional theory (DFT) simulations. The CAM-B3LYP and ωB97XD functionals were found to be most suitable for modeling the measured data. The secondary structure of the α-synuclein models was monitored by electronic and vibrational circular dichroism (ECD and VCD) spectroscopies and modeled by molecular dynamics (MD) simulations. The results suggest that the nitration in these peptides has a limited effect on the secondary structure, but may trigger their aggregation.
- MeSH
- Azo Compounds chemistry MeSH
- Circular Dichroism MeSH
- Peptides chemical synthesis chemistry MeSH
- Spectrum Analysis, Raman methods MeSH
- Protein Structure, Secondary MeSH
- Molecular Dynamics Simulation MeSH
- Density Functional Theory MeSH
- Tyrosine analogs & derivatives analysis MeSH
- Publication type
- Journal Article MeSH
Mitochondria are exposed to reactive nitrogen species under physiological conditions and even more under several pathologic states. In order to reveal the mechanism of these processes we studied the effects of peroxynitrite on isolated beef heart mitochondria in vitro. Peroxynitrite has the potential to nitrate protein tyrosine moieties, break the peptide bond, and eventually release the membrane proteins into the solution. All these effects were found in our experiments. Mitochondrial proteins were resolved by 2D electrophoresis and the protein nitration was detected by immunochemical methods and by nano LC-MS/MS. Mass spectrometry confirmed nitration of ATP synthase subunit beta, pyruvate dehydrogenase E1 component subunit beta, citrate synthase and acetyl-CoA acetyltransferase. Immunoblot detection using chemiluminiscence showed possible nitration of other proteins such as cytochrome b-c1 complex subunit 1, NADH dehydrogenase [ubiquinone] iron-sulfur protein 2, elongation factor Tu, NADH dehydrogenase [ubiquinone] flavoprotein 2, heat shock protein beta-1 and NADH dehydrogenase [ubiquinone] iron-sulfur protein 8. ATP synthase beta subunit was nitrated both in membrane and in fraction prepared by osmotic lysis. The high sensitivity of proteins to nitration by peroxynitrite is of potential biological importance, as these enzymes are involved in various pathways associated with energy production in the heart.
- MeSH
- Nitrogen metabolism MeSH
- Peroxynitrous Acid pharmacology MeSH
- Mitochondrial Proteins drug effects metabolism MeSH
- Proteomics * MeSH
- Cattle MeSH
- Mitochondria, Heart drug effects enzymology metabolism MeSH
- In Vitro Techniques MeSH
- Tyrosine analogs & derivatives metabolism MeSH
- Animals MeSH
- Check Tag
- Cattle MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- MeSH
- Erythrocyte Membrane drug effects MeSH
- Erythrocytes physiology metabolism MeSH
- Phagocytosis genetics MeSH
- Research Support as Topic MeSH
- Microscopy, Fluorescence MeSH
- Humans MeSH
- Luminescence MeSH
- Macrophages physiology MeSH
- Lipid Peroxidation MeSH
- Respiratory Burst genetics MeSH
- Tyrosine analogs & derivatives MeSH
- Check Tag
- Humans MeSH
Oxidative stress may cause extended tyrosine posttranslational modifications of peptides and proteins. The 3-nitro-L-tyrosine (Nit), which is typically formed, affects protein behavior during neurodegenerative processes, such as Alzheimer's and Parkinson's diseases. Such metabolic products may be conveniently detected at very low concentrations by surface enhanced Raman spectroscopy (SERS). Previously, we have explored the SERS detection of the Nit NO2 bending vibrational bands in a presence of hydrogen chloride (Niederhafner et al., Amino Acids 53:517-532, 2021, ibid). In this article, we describe performance of a new SERS substrate, "pink silver", synthesized photochemically. It provides SERS even without the HCl induction, and the acid further decreases the detection limit about 9 times. Strong SERS bands were observed in the asymmetric (1550-1475 cm-1) and symmetric (1360-1290 cm-1) NO stretching in the NO2 group. The bending vibration was relatively weak, but appeared stronger when HCl was added. The band assignments were supported by density functional theory modeling.
- MeSH
- Nitrogen Dioxide MeSH
- Peptides MeSH
- Proteins MeSH
- Spectrum Analysis, Raman * methods MeSH
- Silver * chemistry MeSH
- Publication type
- Journal Article MeSH
A new method of determination of nitrate was developed, utilizing the nitrate reductase activity of Paracoccus denitrificans in which a further reduction of nitrate is blocked either by a mutation affecting formation of cytochromes c or by inhibition of the electron flow to nitrite reductase by mucidin. After deproteinization of the sample with zinc acetate the nitrite produced is determined colorimetrically.
Nitráty jsou používány v kardiologické léčbě již déle než sto let. Působí prostřednictvím uvolňovaného oxidu dusnatého (NO), který je obdobou endogenního endotelového relaxačního faktoru (EDRF). Nejpoužívanější jsou nitroglycerin, izosorbid dinitrát a izosorbid-5-mononitrát. K nim se svými obdobnými účinky řadí molsidomin. Nitráty mají široké spektrum účinků, jejichž výsledkem je antiischemický a antianginózní efekt. Významné je působení antiagregační. Nežádoucí účinky nitrátů nejsou závažné. Nitráty jsou užívány v symptomatické léčbě prakticky všech forem ICHS. Příznivě ovlivňují prognózu nemocných se srdečním selháním, časnou i pozdní remodelaci levé komory srdeční po infarktu myokardu a výskyt němé ischemie. Jsou používány v akutní (krátkodobé) i dlouhodobé léčbě. Specifickým rysem chronického podávání nitrátů je vznik tolerance. Tento problém lze odstranit úpravou dávkovacího režimu.
Nitrates have been applied in cardiology over one hundred years. They act via nitric oxide release. Nitric oxide is the same substance as endogenous endothelium-derived relaxing factor (EDRF). The most frequently used nitrates are nitroglycerin, isosorbide dinitrate and isosorbide-5-mononitrate and similarly acting moledidomine. The wide range of actions results in antiischemic and antianginal effect. The inhibition of platelet a aggregation is important as well. Nitrates have no significant adverse effects. They are used in symptomatic treatment of nearly all forms of coronary heart disease. They improve prognosis of patients with heart failure and have favourable effects on early and late left ventricle remodeling post myocardial infarction as well as on incidence of silent ischemia. Nitrates are used both for acute (short-term) and for long-term therapy. The may latter lead to development of tolerance, which can be prevented or reversed with intermittent-dosing regimens.
- MeSH
- Nitrates pharmacology classification therapeutic use MeSH
- Cardiovascular Diseases drug therapy MeSH
- Humans MeSH
- Nitric Oxide physiology chemistry physiology MeSH
- Drug Administration Schedule MeSH
- Drug Tolerance physiology MeSH
- Vasodilation physiology drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
Orchids are distributed around the world, however, the factors shaping their specific distribution and habitat preferences are largely unknown. Moreover, many orchids are at risk of becoming threatened as landscapes change, sometimes declining without apparent reason. One important factor affecting plant distribution is nutrient levels in the environment. Nitrates can inhibit not only orchid growth and persistence, but also seed germination. We used in vitro axenic cultures to exactly determine the germination sensitivity of seven orchid species to nitrates and correlated this with soil properties of the natural sites and with the species' habitat preferences. We found high variation in response to nitrate between species. Orchids from oligotrophic habitats were highly sensitive, while orchids from more eutrophic habitats were almost insensitive. Sensitivity to nitrate was also associated with soil parameters that indicated a higher nitrification rate. Our results indicate that nitrate can affect orchid distribution via direct inhibition of seed germination. Nitrate levels in soils are increasing rapidly due to intensification of agricultural processes and concurrent soil pollution, and we propose this increase could cause a decline in some orchid species.
- MeSH
- Nitrates * analysis toxicity MeSH
- Ecosystem * MeSH
- Orchidaceae * drug effects physiology MeSH
- Soil * chemistry MeSH
- Seeds * drug effects MeSH
- Publication type
- Journal Article MeSH
