Aldehyde dehydrogenases (ALDHs) represent a superfamily of enzymes, which oxidize aldehydes to the corresponding acids. Certain families, namely ALDH9 and ALDH10, are best active with ω-aminoaldehydes arising from the metabolism of polyamines such as 3-aminopropionaldehyde and 4-aminobutyraldehyde. Plant ALDH10s show broad specificity and accept many different aldehydes (aliphatic, aromatic and heterocyclic) as substrates. This work involved the above-mentioned aminoaldehydes acylated with dicarboxylic acids, phenylalanine, and tyrosine. The resulting products were then examined with native ALDH10 from pea and recombinant ALDH7s from pea and maize. This investigation aimed to find a common efficient substrate for the two plant ALDH families. One of the best natural substrates of ALDH7s is aminoadipic semialdehyde carrying a carboxylic group opposite the aldehyde group. The substrate properties of the new compounds were demonstrated by mass spectrometry of the reaction mixtures, spectrophotometric assays and molecular docking. The N-carboxyacyl derivatives were good substrates of pea ALDH10 but were only weakly oxidized by the two plant ALDH7s. The N-phenylalanyl and N-tyrosyl derivatives of 3-aminopropionaldehyde were good substrates of pea and maize ALDH7. Particularly the former compound was converted very efficiently (based on the kcat/Km ratio), but it was only weakly oxidized by pea ALDH10. Although no compound exhibited the same level of substrate properties for both ALDH families, we show that these enzymes may possess more common substrates than expected.

• Klíčová slova
• Acylation, Aldehyde dehydrogenase, Aminoaldehyde, Docking, Enzyme, Substrate,
• MeSH
• aldehyddehydrogenasa * metabolismus   chemie   genetika   MeSH
• aldehydy * metabolismus   chemie   MeSH
• hrách setý * enzymologie   MeSH
• kinetika MeSH
• kukuřice setá * enzymologie   MeSH
• oxidace-redukce MeSH
• rostlinné proteiny metabolismus   chemie   genetika   MeSH
• simulace molekulového dockingu * MeSH
• substrátová specifita MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aldehyddehydrogenasa * MeSH
• aldehydy * MeSH
• rostlinné proteiny 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.

• Klíčová slova
• Nitration, Oxidative stress, Photochemical synthesis, Posttranslational protein modification (PTM), Silver colloids, Surface enhanced Raman spectroscopy (SERS),
• MeSH
• oxid dusičitý MeSH
• peptidy MeSH
• proteiny MeSH
• Ramanova spektroskopie * metody   MeSH
• stříbro * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid dusičitý MeSH
• peptidy MeSH
• proteiny MeSH
• stříbro * MeSH

Naturally occurring secondary amino acids, with proline as the main representative, contain an alpha-imino group in a cycle that is typically four-, five-, and six-membered. The unique ring structure exhibits exceptional properties-conformational rigidity, chemical stability, and specific roles in protein structure and folding. Many proline analogues have been used as valuable compounds for the study of metabolism of both prokaryotic and eukaryotic cells and for the synthesis of compounds with desired biological, pharmaceutical, or industrial properties. The D-forms of secondary amino acids play different roles in living organisms than the L-forms. They have different metabolic pathways, biological, physiological, and pharmacological effects, they can be indicators of changes and also serve as biomarkers of diseases. In the scientific literature, the number of articles examining D-amino acids in biological samples is increasing. The review summarises information on the occurrence and importance of D- and L-secondary amino acids-azetidic acid, proline, hydroxyprolines, pipecolic, nipecotic, hydroxypipecolic acids and related peptides containing these D-AAs, as well as the main analytical methods (mostly chromatographic) used for their enantiomeric determination in different matrices (biological samples, plants, food, water, and soil).

• Klíčová slova
• Chiral analysis, D- and L-secondary amino acids, Enantiomers, Imino acids, Proline analogues,
• MeSH
• aminokyseliny * chemie   MeSH
• iminokyseliny * chemie   MeSH
• peptidy MeSH
• prolin chemie   MeSH
• stereoizomerie MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• aminokyseliny * MeSH
• iminokyseliny * MeSH
• peptidy MeSH
• prolin MeSH

Post-translational modified thiazole-amino acid (Xaa-Tzl) residues have been found in macrocyclic peptides (e.g., thiopeptides and cyanobactins), which mostly inhibit protein synthesis in Gram + bacteria. Conformational study of the series of model compounds containing this structural motif with alanine, dehydroalanine, dehydrobutyrine and dehydrophenylalanine were performed using DFT method in various environments. The solid-state crystal structure conformations of thiazole-amino acid residues retrieved from the Cambridge Structural Database were also analysed. The studied structural units tend to adopt the unique semi-extended β2 conformation; which is stabilised mainly by N-H⋯NTzl hydrogen bond, and for dehydroamino acids also by π-electron conjugation. The conformational preferences of amino acids with a thiazole ring were compared with oxazole analogues and the role of the sulfur atom in stabilising the conformations of studied peptides was discussed.

• Klíčová slova
• Conformational analysis, DFT, Hydrogen bond, Non-standard amino acids, Ramachandran map, Thiazole,
• MeSH
• aminokyseliny chemie   MeSH
• molekulární konformace MeSH
• peptidy chemická syntéza   chemie   MeSH
• thiazoly chemie   MeSH
• vodíková vazba MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminokyseliny MeSH
• peptidy MeSH
• thiazoly 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.

• Klíčová slova
• Density functional theory (DFT), Electronic circular dichroism (ECD), Nitration, Oxidative stress, Surface-enhanced Raman spectroscopy (SERS), Vibrational circular dichroism (VCD),
• MeSH
• azosloučeniny chemie   MeSH
• cirkulární dichroismus MeSH
• peptidy chemická syntéza   chemie   MeSH
• Ramanova spektroskopie metody   MeSH
• sekundární struktura proteinů MeSH
• simulace molekulární dynamiky MeSH
• teorie funkcionálu hustoty MeSH
• tyrosin analogy a deriváty   analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 3-nitrotyrosine MeSH Prohlížeč
• azobenzene MeSH Prohlížeč
• azosloučeniny MeSH
• peptidy MeSH
• tyrosin MeSH

L-amino acids (L-AAs) play different important roles in the physiology of all living organisms. Their chiral counterparts, D-amino acids (D-AAs) are increasingly being recognized as essential molecules in many biological systems. Secondary amino acids with cyclic structures, such as prolines, exhibit conformational rigidity and thus unique properties in the structural and protein folding. Despite their widespread occurrence, much less attention was paid to their chiral analysis, particularly when the minor, typically D-enantiomer, is present in low amounts in a complex biological matrix. In this paper, a cost-effective, chiral GC-MS method is described for capillary Chirasil-L-Val separation of nine cyclic secondary amino acid enantiomers with four-, five-, and six-membered rings, involving azetidine-2-carboxylic acid, pipecolic acid, nipecotic acid, proline, isomeric cis/trans 3-hydroxy, 4-hydroxyproline, and cis/trans-5-hydroxy-L-pipecolic acid in the excess of its enantiomeric antipode. The sample preparation involves in-situ derivatization with heptafluorobutyl chloroformate, simultaneous liquid-liquid micro-extraction into isooctane followed by amidation of the arising low-polar derivatives with methylamine, an evaporation step, re-dissolution, and final GC-MS analysis. The developed method was used for analyses of human biofluids, biologically active peptides containing chiral proline constituents, and collagen.

• Klíčová slova
• Enantiomeric separation, GC–MS, Heptafluorobutyl chloroformate, Imino acids, Methyl amide derivatives, Secondary amino acids,
• MeSH
• fluorokarbony chemie   MeSH
• formiáty chemie   MeSH
• iminokyseliny analýza   chemie   MeSH
• kalibrace MeSH
• lidé MeSH
• methylaminy chemie   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí metody   normy   MeSH
• reprodukovatelnost výsledků MeSH
• stereoizomerie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fluorokarbony MeSH
• formiáty MeSH
• heptafluorobutyl chloroformate MeSH Prohlížeč
• iminokyseliny MeSH
• methylamine MeSH Prohlížeč
• methylaminy MeSH

Drug compounds including memantine moieties are an important group of biologically active agents for different pathologies, including the Alzheimer's disease. In the present study, a series of memantine derivatives incorporating amino acid residues have been synthesized and their neuroprotective in vitro evaluation in respect of the Alzheimer's disease, involving the effects on the resistance to Aβ toxicity, excitotoxicity, oxidative stress, hypoxia, and neuroinflammation has been studied. The cytotoxicities of the compounds were detected by CPE assay. TC50 and IC50 were determined using Reed and Muench method. Solubility and distribution were measured using a shake-flask method. Permeability of the compounds was studied using Franz diffusion cell and Permeapad™ barrier. These compounds displayed apparent multi-neuroprotective effects against copper-triggered Aβ toxicity, glutamate-induced excitotoxicity, and oxidative and hypoxic injuries. They also showed the ability to inhibit the inflammatory cytokine release from the activated microglia and potential anti-neuroinflammatory effects. Especially, two most promising compounds H-4-F-Phe-memantine and H-Tyr-memantine demonstrated the equivalent functional bioactivities in comparison with the positive control memantine hydrochloride. Higher solubility in muriatic buffer than in phosphate buffer was detected. The distribution coefficients showed the optimal lipophilicity for compounds. The presented results propose new class of memantine derivatives as potential drug compounds. Based on the experimental results, the correlations have been obtained between the biological, physicochemical parameters and structural descriptors. The correlation equations have been proposed to predict the properties of new memantine derivatives knowing only the structural formula.

• Klíčová slova
• Alzheimer’s disease, Amino acids, Memantine,
• MeSH
• Alzheimerova nemoc farmakoterapie   genetika   patologie   MeSH
• amyloidní beta-protein účinky léků   toxicita   MeSH
• buňky MDCK MeSH
• chřipka lidská farmakoterapie   virologie   MeSH
• kyselina glutamová metabolismus   MeSH
• lidé MeSH
• memantin analogy a deriváty   chemie   farmakologie   MeSH
• neuroprotektivní látky chemie   farmakologie   MeSH
• Orthomyxoviridae účinky léků   patogenita   MeSH
• oxidační stres účinky léků   MeSH
• psi MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• amyloidní beta-protein MeSH
• kyselina glutamová MeSH
• memantin MeSH
• neuroprotektivní látky MeSH

The combination of different nanomaterials has been investigated during the past few decades and represents an exciting challenge for the unexpected emerging properties of the resulting nano-hybrids. Spermidine (Spd), a biogenic polyamine, has emerged as a useful functional monomer for the development of carbon quantum dots (CQDs). Herein, an electrostatically stabilized ternary hybrid, constituted of iron oxide-DNA (the core) and spermidine carbon quantum dots (CQDSpds, the shell), was self-assembled and fully characterized. The as-obtained nano-hybrid was tested on HeLa cells to evaluate its biocompatibility as well as cellular uptake. Most importantly, besides being endowed by the magnetic features of the core, it displayed drastically enhanced fluorescence properties in comparison with parent CQDSpds and it is efficiently internalized by HeLa cells. This novel ternary nano-hybrid with multifaceted properties, ranging from fluorescence to superparamagnetism, represents an interesting option for cell tracking.

• Klíčová slova
• Carbon quantum dots, Cell tracker, Magnetic nanoparticle, Nano-hybrid, Spermidine,
• MeSH
• biotechnologie MeSH
• fluorescence MeSH
• HeLa buňky MeSH
• kvantové tečky chemie   metabolismus   MeSH
• lidé MeSH
• nanostruktury chemie   MeSH
• polyaminy chemie   metabolismus   MeSH
• statická elektřina MeSH
• uhlík chemie   metabolismus   MeSH
• železité sloučeniny chemie   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ferric oxide MeSH Prohlížeč
• polyaminy MeSH
• uhlík MeSH
• železité sloučeniny MeSH

The unique capability of proton buffering is the rationale for using histidine (HIS) as a component of solutions for induction of cardiac arrest and myocardial protection in cardiac surgery. In humans, infusion of cardioplegic solution may increase blood plasma HIS from ~ 70 to ~ 21,000 µM. We examined the effects of a large intravenous dose of HIS on ammonia and amino acid concentrations and energy status of the body. Rats received 198 mM HIS intravenously (20 ml/kg) or vehicle. Samples of blood plasma, urine, liver, and soleus (SOL) and extensor digitorum longus (EDL) muscles were analysed at 2 or 24 h after treatment. At 2 h after HIS load, we found higher HIS concentration in all examined tissues, higher urea and ammonia concentrations in blood and urine, lower ATP content and higher AMP/ATP ratio in the liver and muscles, higher concentrations of almost all examined amino acids in urine, and lower glycine concentration in blood plasma, liver, and muscles when compared with controls. Changes in other amino acids were tissue dependent, markedly increased alanine and glutamate in the blood and the liver. At 24 h, the main findings were lower ATP concentrations in muscles, lower concentrations of branched-chain amino acids (BCAA; valine, leucine, and isoleucine) in blood plasma and muscles, and higher carnosine content in SOL when compared with controls. It is concluded that a load of large HIS dose results in increased ammonia levels and marked alterations in amino acid and energy metabolism. Pathogenesis is discussed in the article.

• Klíčová slova
• ATP depletion, Ammonia, Branched-chain amino acids, Glutamine, Glycine, HTK solution, Ketoglutarate, Myocardial protection, Tetrahydrofolate,
• MeSH
• adeninnukleotidy metabolismus   MeSH
• aminokyseliny chemie   metabolismus   MeSH
• amoniak metabolismus   MeSH
• energetický metabolismus MeSH
• histidin aplikace a dávkování   analýza   metabolismus   MeSH
• intravenózní podání MeSH
• kardioplegické roztoky chemie   MeSH
• karnosin metabolismus   MeSH
• krysa rodu Rattus MeSH
• kyseliny ketoglutarové metabolismus   MeSH
• močovina metabolismus   MeSH
• orgánová specificita MeSH
• potkani Wistar MeSH
• tkáňová distribuce MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adeninnukleotidy MeSH
• aminokyseliny MeSH
• amoniak MeSH
• histidin MeSH
• kardioplegické roztoky MeSH
• karnosin MeSH
• kyseliny ketoglutarové MeSH
• močovina MeSH

This errata is for paper "Rapid acidolysis of benzyl group as a suitable approach for syntheses.

• Publikační typ
• časopisecké články MeSH
• tisková chyba MeSH