The metabolic degradation of aldehydes is catalyzed by oxidoreductases from which aldehyde dehydrogenases (EC 1.2.1) comprise nonspecific or substrate-specific enzymes. The latter subset is represented, e.g., by NAD(+)-dependent aminoaldehyde dehydrogenases (AMADHs; EC 1.2.1.19) oxidizing a group of naturally occurring ω-aminoaldehydes including polyamine oxidation products. Recombinant isoenzymes from pea (PsAMADH1 and 2) and tomato (LeAMADH1 and 2) were subjected to kinetic measurements with synthetic aldehydes containing a nitrogenous heterocycle such as pyridinecarbaldehydes and their halogenated derivatives, (pyridinylmethylamino)-aldehydes, pyridinyl propanals and aldehydes derived from purine, 7-deazapurine and pyrimidine to characterize their substrate specificity and significance of the resulting data for in vivo reactions. The enzymatic production of the corresponding carboxylic acids was analyzed by liquid chromatography coupled to electrospray ionization mass spectrometry. Although the studied AMADHs are largely homologous and supposed to have a very similar active site architecture, significant differences were observed. LeAMADH1 displayed the broadest specificity oxidizing almost all compounds followed by PsAMADH2 and 1. In contrast, LeAMADH2 accepted only a few compounds as substrates. Pyridinyl propanals were converted by all isoenzymes, usually better than pyridinecarbaldehydes and aldehydes with fused rings. The K (m) values for the best substrates were in the range of 10(-5)-10(-4) M. Nevertheless, the catalytic efficiency values (V (max)/K (m)) reached only a very small fraction of that with 3-aminopropanal (except for LeAMADH1 activity with two pyridine-derived compounds). Docking experiments using the crystal structure of PsAMADH2 were involved to discuss differences in results with position isomers or alkyl chain homologs.

• MeSH
• aldehydoxidoreduktasy chemie   MeSH
• aldehydy chemie   MeSH
• aminokyselinové motivy MeSH
• heterocyklické sloučeniny chemie   MeSH
• hrách setý enzymologie   MeSH
• katalytická doména MeSH
• kinetika MeSH
• molekulární modely MeSH
• počítačová simulace MeSH
• rekombinantní proteiny chemie   MeSH
• rostlinné proteiny chemie   MeSH
• Solanum lycopersicum enzymologie   MeSH
• substrátová specifita MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

RATIONALE: Peroxidation of lipids in cellular membranes results in the release of volatile organic compounds (VOCs), including saturated aldehydes. The real-time quantification of trace VOCs produced by cancer cells during peroxidative stress presents a new challenge to non-invasive clinical diagnostics, which as described here, we have met with some success. METHODS: A combination of selected ion flow tube mass spectrometry (SIFT-MS), a technique that allows rapid, reliable quantification of VOCs in humid air and liquid headspace, and electrochemistry to generate reactive oxygen species (ROS) in vitro has been used. Thus, VOCs present in the headspace of CALU-1 cancer cell line cultures exposed to ROS have been monitored and quantified in real time using SIFT-MS. RESULTS: The CALU-1 lung cancer cells were cultured in 3D collagen to mimic in vivo tissue. Real-time SIFT-MS analyses focused on the volatile aldehydes: propanal, butanal, pentanal, hexanal, heptanal and malondialdehyde (propanedial), that are expected to be products of cellular membrane peroxidation. All six aldehydes were identified in the culture headspace, each reaching peak concentrations during the time of exposure to ROS and eventually reducing as the reactants were depleted in the culture. Pentanal and hexanal were the most abundant, reaching concentrations of a few hundred parts-per-billion by volume, ppbv, in the culture headspace. CONCLUSIONS: The results of these experiments demonstrate that peroxidation of cancer cells in vitro can be monitored and evaluated by direct real-time analysis of the volatile aldehydes produced. The combination of adopted methodology potentially has value for the study of other types of VOCs that may be produced by cellular damage.

• MeSH
• aldehydy analýza   metabolismus   MeSH
• buněčné kultury metody   MeSH
• elektrochemické techniky MeSH
• hmotnostní spektrometrie metody   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádory metabolismus   MeSH
• oxidace-redukce MeSH
• oxidační stres fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Due to their enhanced reactivity, metal and metal-oxide nanoscale zero-valent iron (nZVI) nanomaterials have been introduced into remediation practice. To ensure that environmental applications of nanomaterials are safe, their possible toxic effects should be described. However, there is still a lack of suitable toxicity tests that address the specific mode of action of nanoparticles, especially for nZVI. This contribution presents a novel approach for monitoring one of the most discussed adverse effects of nanoparticles, i.e., oxidative stress (OS). We optimized and developed an assay based on headspace-SPME-GC-MS analysis that enables the direct determination of volatile oxidative damage products (aldehydes) of lipids and proteins in microbial cultures after exposure to commercial types of nZVI. The method employs PDMS/DVB SPME fibers and pentafluorobenzyl derivatization, and the protocol was successfully tested using representatives of bacteria, fungi, and algae. Six aldehydes, namely, formaldehyde, acrolein, methional, benzaldehyde, glyoxal, and methylglyoxal, were detected in the cultures, and all of them exhibited dose-dependent sigmoidal responses. The presence of methional, which was detected in all cultures except those including an algal strain, documents that nZVI also caused oxidative damage to proteins in addition to lipids. The most sensitive toward nZVI exposure in terms of aldehyde production was the yeast strain Saccharomyces cerevisiae, which had an EC50 value of 0.08 g/L nZVI. To the best of our knowledge, this paper is the first to document the production of aldehydes resulting from lipids and proteins as a result of OS in microorganisms from different kingdoms after exposure to iron nanoparticles.

• MeSH
• aldehydy farmakologie   MeSH
• Bacteria účinky léků   MeSH
• kovové nanočástice toxicita   MeSH
• lipidy MeSH
• nanostruktury MeSH
• oxidace-redukce MeSH
• oxidační stres fyziologie   MeSH
• testy toxicity MeSH
• železité sloučeniny MeSH
• železo metabolismus   toxicita   MeSH
• Publikační typ
• časopisecké články MeSH

Aza-peptide aldehydes and ketones are a new class of reversible protease inhibitors that are specific for the proteasome and clan CD cysteine proteases. We designed and synthesised aza-Leu derivatives that were specific for the chymotrypsin-like active site of the proteasome, aza-Asp derivatives that were effective inhibitors of caspases-3 and -6, and aza-Asn derivatives that inhibited S. mansoni and I. ricinus legumains. The crystal structure of caspase-3 in complex with our caspase-specific aza-peptide methyl ketone inhibitor with an aza-Asp residue at P1 revealed a covalent linkage between the inhibitor carbonyl carbon and the active site cysteinyl sulphur. Aza-peptide aldehydes and ketones showed no cross-reactivity towards cathepsin B or chymotrypsin. The initial in vitro selectivity of these inhibitors makes them suitable candidates for further development into therapeutic agents to potentially treat multiple myeloma, neurodegenerative diseases, and parasitic infections.

• MeSH
• aldehydy chemie   farmakologie   MeSH
• aza sloučeniny chemie   farmakologie   MeSH
• cysteinové endopeptidasy metabolismus   MeSH
• inhibitory proteas chemická syntéza   chemie   farmakologie   MeSH
• ketony chemie   farmakologie   MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• peptidy chemie   farmakologie   MeSH
• proteasomový endopeptidasový komplex metabolismus   MeSH
• racionální návrh léčiv * MeSH
• skot MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Lipid peroxidation induced by oxidants leads to the formation of highly reactive metabolites. These can affect various immune functions, including reactive oxygen species (ROS) and nitric oxide (NO) production. The aim of the present study was to investigate the effects of lipid peroxidation products (LPPs) - acrolein, 4-hydroxynonenal, and malondialdehyde - on ROS and NO production in RAW 264.7 macrophages and to compare these effects with the cytotoxic properties of LPPs. Macrophages were stimulated with lipopolysaccharide (0.1 μg/ml) and treated with selected LPPs (concentration range: 0.1-100 μM). ATP test, luminol-enhanced chemiluminescence, Griess reaction, Western blotting analysis, amperometric and total peroxyl radical-trapping antioxidant parameter assay were used for determining the LPPs cytotoxicity, ROS and NO production, inducible nitric oxide synthase expression, NO scavenging, and antioxidant properties of LPPs, respectively. Our study shows that the cytotoxic action of acrolein and 4-hydroxynonenal works in a dose- and time-dependent manner. Further, our results imply that acrolein, 4-hydroxynonenal, and malondialdehyde can inhibit, to a different degree, ROS and NO production in stimulated macrophages, partially independently of their toxic effect. Also, changes in enzymatic pathways (especially NADPH-oxidase and nitric oxide synthase inhibition) and NO scavenging properties are included in the downregulation of reactive species formation.

• MeSH
• akrolein toxicita   MeSH
• aktivace makrofágů MeSH
• aldehydy toxicita   MeSH
• časové faktory MeSH
• down regulace účinky léků   MeSH
• dusitany metabolismus   MeSH
• lipopolysacharidy imunologie   MeSH
• makrofágy imunologie   metabolismus   MeSH
• malondialdehyd toxicita   MeSH
• myši MeSH
• NADPH-oxidasy antagonisté a inhibitory   MeSH
• osmolární koncentrace MeSH
• oxid dusnatý antagonisté a inhibitory   metabolismus   MeSH
• peroxidace lipidů MeSH
• reaktivní formy kyslíku antagonisté a inhibitory   metabolismus   MeSH
• scavengery volných radikálů farmakologie   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• transformované buněčné linie MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Reactive α,β-unsaturated aldehydes, including 4-oxoalk-2-enals, are known to be present in volatile secretions of numerous heteropteran insect species. Because the aldehydes are likely to originate from metabolism of fatty acids (FAs), the present study aimed to examine and compare the aldehyde and FA profiles of four model heteropteran species. The model species consisted of adult family group representatives within the infraorder Pentatomomorpha (Hemiptera: Heteroptera): seed bug (Lygaeus equestris (Lygaeoidea)), dock leaf bug (Coreus marginatus (Coreoidea)), red firebug (Pyrrhocoris apterus (Pyrrhocoroidea)), and European stink bug (Graphosoma lineatum (Pentatomoidea)). Solid-phase microextraction combined with two-dimensional gas-chromatography/time-of-flight mass spectrometry was used to establish the profiles of volatile secretions in stressed living insects. The FA profiles of acylglyceride and phospholipid fractions deposited in fat body and/or hemolymph were obtained by liquid chromatography/mass spectrometry and gas chromatography with flame ionization detection techniques. Our results based on multivariate statistical analyses of the data imply that volatile secretion blends as well as fat body and/or hemolymph lipid profiles are species specific but the differences in volatile blends between different species do not mirror the changes in corresponding fat body and/or hemolymph lipid profiles of stressed and non-stressed individuals.

• MeSH
• aldehydy analýza   MeSH
• druhová specificita MeSH
• fyziologický stres MeSH
• hemolymfa MeSH
• Heteroptera chemie   MeSH
• mastné kyseliny analýza   MeSH
• mikroextrakce na pevné fázi MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• tukové těleso MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Proteins are subject to oxidative modification and the formation of adducts with a broad spectrum of reactive species via enzymatic and non-enzymatic mechanisms. Here we report that in vitro non-enzymatic methylglyoxal (MGO) binding causes the inhibition and formation of MGO advanced glycation end-products (MAGEs) in Na+/K+-ATPase (NKA). Concretely, MGO adducts with NKA amino acid residues (mainly Arg) and Nε-(carboxymethyl)lysine (CML) formation were found. MGO is not only an inhibitor for solubilized NKA (IC50=91±16μM), but also for reconstituted NKA in the lipid bilayer environment, which was clearly demonstrated using a DPPC/DPPE liposome model in the presence or absence of the NKA-selective inhibitor ouabain. High-resolution mass spectrometric analysis of a tryptic digest of NKA isolated from pig (Sus scrofa) kidney indicates that the intracellular α-subunit is naturally (post-translationally) modified by MGO in vivo. In contrast to this, the β-subunit could only be modified by MGO artificially, and the transmembrane part of the protein did not undergo MGO binding under the experimental setup used. As with bovine serum albumin, serving as the water-soluble model, we also demonstrated a high binding capacity of MGO to water-poorly soluble NKA using a multi-spectral methodology based on electroanalytical, immunochemical and fluorimetric tools. In addition, a partial suppression of the MGO-mediated inhibitory effect could be observed in the presence of aminoguanidine (pimagedine), a glycation suppressor and MGO-scavenger. All the results here were obtained with the X-ray structure of NKA in the E1 conformation (3WGV) and could be used in the further interpretation of the functionality of this key enzyme in the presence of highly-reactive metabolic side-products, glycation agents and generally under oxidative stress conditions.

• MeSH
• guanidiny farmakologie   MeSH
• hmotnostní spektrometrie MeSH
• konformace proteinů MeSH
• krystalografie rentgenová MeSH
• ledviny metabolismus   MeSH
• ouabain farmakologie   MeSH
• oxidační stres MeSH
• produkty pokročilé glykace chemie   metabolismus   MeSH
• pyruvaldehyd chemie   metabolismus   MeSH
• sérový albumin hovězí metabolismus   MeSH
• skot MeSH
• sodíko-draslíková ATPasa antagonisté a inhibitory   chemie   metabolismus   MeSH
• Sus scrofa MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The chain coordination polymerization of (ethynylarene)carbaldehydes with unprotected carbaldehyde groups, namely ethynylbenzaldehydes, 1-ethynylbenzene-3,5-dicarboxaldehyde, and 3-[(4-ethynylphenyl)ethynyl]benzaldehyde, is reported for the first time. Polymerization is catalyzed with various Rh(I) catalysts and yields poly(arylacetylene)s with one or two pendant carbaldehyde groups per monomeric unit. Surprisingly, the carbaldehyde groups of the monomers do not inhibit the polymerization unlike the carbaldehyde group of unsubstituted benzaldehyde that acts as a strong inhibitor of Rh(I) catalyzed polymerization of arylacetylenes. The inhibition ability of carbaldehyde groups in (ethynylarene)carbaldehydes seems to be eliminated owing to a simultaneous presence of unsaturated ethynyl groups in (ethynylarene)carbaldehydes. The reactive carbaldehyde groups make poly[(ethynylarene)carbaldehyde]s promising for functional appreciation via various postpolymerization modifications. The introduction of photoluminescence or chirality to poly(ethynylbenzaldehyde)s via quantitative modification of their carbaldehyde groups in reaction with either photoluminescent or chiral primary amines under formation of the polymers with Schiff-base-type pendant groups is given as an example.

• MeSH
• aldehydy chemie   MeSH
• benzaldehydy chemie   MeSH
• chemické modely MeSH
• fluorescenční spektrometrie MeSH
• katalýza MeSH
• molekulární struktura MeSH
• polyacetyleny chemická syntéza   chemie   MeSH
• polymerizace * MeSH
• polymery chemická syntéza   chemie   MeSH
• protonová magnetická rezonanční spektroskopie MeSH
• Publikační typ
• časopisecké články MeSH

Aldehyde dehydrogenases (ALDHs) are responsible for oxidation of biogenic aldehyde intermediates as well as for cell detoxification of aldehydes generated during lipid peroxidation. So far, 13 ALDH families have been described in plants. In the present study, we provide a detailed biochemical characterization of plant ALDH2 and ALDH7 families by analysing maize and pea ALDH7 (ZmALDH7 and PsALDH7) and four maize cytosolic ALDH(cALDH)2 isoforms RF2C, RF2D, RF2E and RF2F [the first maize ALDH2 was discovered as a fertility restorer (RF2A)]. We report the crystal structures of ZmALDH7, RF2C and RF2F at high resolution. The ZmALDH7 structure shows that the three conserved residues Glu(120), Arg(300) and Thr(302) in the ALDH7 family are located in the substrate-binding site and are specific to this family. Our kinetic analysis demonstrates that α-aminoadipic semialdehyde, a lysine catabolism intermediate, is the preferred substrate for plant ALDH7. In contrast, aromatic aldehydes including benzaldehyde, anisaldehyde, cinnamaldehyde, coniferaldehyde and sinapaldehyde are the best substrates for cALDH2. In line with these results, the crystal structures of RF2C and RF2F reveal that their substrate-binding sites are similar and are formed by an aromatic cluster mainly composed of phenylalanine residues and several nonpolar residues. Gene expression studies indicate that the RF2C gene, which is strongly expressed in all organs, appears essential, suggesting that the crucial role of the enzyme would certainly be linked to the cell wall formation using aldehydes from phenylpropanoid pathway as substrates. Finally, plant ALDH7 may significantly contribute to osmoprotection because it oxidizes several aminoaldehydes leading to products known as osmolytes.

• MeSH
• aldehyddehydrogenasa chemie   genetika   metabolismus   MeSH
• fylogeneze MeSH
• hrách setý enzymologie   genetika   MeSH
• izoenzymy chemie   genetika   metabolismus   MeSH
• katalytická doména genetika   MeSH
• kinetika MeSH
• krystalografie rentgenová MeSH
• kukuřice setá enzymologie   genetika   MeSH
• modely genetické MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• NAD metabolismus   MeSH
• rostlinné proteiny chemie   genetika   metabolismus   MeSH
• rostliny enzymologie   genetika   MeSH
• sekvence aminokyselin MeSH
• stanovení celkové genové exprese MeSH
• substrátová specifita MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Inflammation and oxidative and dicarbonyl stress play important roles in the pathogenesis of type 2 diabetes. Metformin is the first-line drug of choice for the treatment of type 2 diabetes because it effectively suppresses gluconeogenesis in the liver. However, its "pleiotropic" effects remain controversial. In the current study, we tested the effects of metformin on inflammation, oxidative and dicarbonyl stress in an animal model of inflammation and metabolic syndrome, using spontaneously hypertensive rats that transgenically express human C-reactive protein (SHR-CRP). We treated 8-month-old male transgenic SHR-CRP rats with metformin (5 mg/kg/day) mixed as part of a standard diet for 4 weeks. A corresponding untreated control group of male transgenic SHR-CRP rats were fed a standard diet without metformin. In a similar fashion, we studied a group of nontransgenic SHR treated with metformin and an untreated group of nontransgenic SHR controls. In each group, we studied 6 animals. Parameters of glucose and lipid metabolism and oxidative and dicarbonyl stress were measured using standard methods. Gene expression profiles were determined using Affymetrix GeneChip Arrays. Statistical significance was evaluated by two-way ANOVA. In the SHR-CRP transgenic strain, we found that metformin treatment decreased circulating levels of inflammatory response marker IL-6, TNFα and MCP-1 while levels of human CRP remained unchanged. Metformin significantly reduced oxidative stress (levels of conjugated dienes and TBARS) and dicarbonyl stress (levels of methylglyoxal) in left ventricles, but not in kidneys. No significant effects of metformin on oxidative and dicarbonyl stress were observed in SHR controls. In addition, metformin treatment reduced adipose tissue lipolysis associated with human CRP. Possible molecular mechanisms of metformin action-studied by gene expression profiling in the liver-revealed deregulated genes from inflammatory and insulin signaling, AMP-activated protein kinase (AMPK) signaling and gluconeogenesis pathways. It can be concluded that in the presence of high levels of human CRP, metformin protects against inflammation and oxidative and dicarbonyl stress in the heart, but not in the kidney. Accordingly, these cardioprotective effects of metformin might be especially effective in diabetic patients with high levels of CRP.

• MeSH
• C-reaktivní protein biosyntéza   genetika   MeSH
• cytokiny metabolismus   MeSH
• exprese genu MeSH
• glukosa metabolismus   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• lipolýza účinky léků   genetika   MeSH
• metformin farmakologie   MeSH
• myokard metabolismus   MeSH
• oxidační stres účinky léků   genetika   MeSH
• potkani inbrední SHR MeSH
• potkani transgenní MeSH
• proteinkinasy aktivované AMP genetika   metabolismus   MeSH
• pyruvaldehyd metabolismus   MeSH
• srdeční komory metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH