structure modification
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- MeSH
- experimenty na zvířatech MeSH
- hemoglobiny účinky záření MeSH
- psi MeSH
- radiační účinky MeSH
- Check Tag
- psi MeSH
Oxidative stress in humans is related to various pathophysiological processes, which can manifest in numerous diseases including cancer, cardiovascular diseases, and Alzheimer's disease. On the atomistic level, oxidative stress causes posttranslational modifications, thus inducing structural and functional changes into the proteins structure. This study focuses on fibrinogen, a blood plasma protein that is frequently targeted by reagents causing posttranslational modifications in proteins. Fibrinogen was in vitro modified by three reagents, namely sodium hypochlorite, malondialdehyde, and 3-morpholinosydnonimine that mimic the oxidative stress in diseases. Newly induced posttranslational modifications were detected via mass spectrometry. Electron microscopy was used to visualize changes in the fibrin networks, which highlight the extent of disturbances in fibrinogen behavior after exposure to reagents. We used molecular dynamics simulations to observe the impact of selected posttranslational modifications on the fibrinogen structure at the atomistic level. In total, 154 posttranslational modifications were identified, 84 of them were in fibrinogen treated with hypochlorite, 51 resulted from a reaction of fibrinogen with malondialdehyde, and 19 were caused by 3-morpholinosydnonimine. Our data reveal that the stronger reagents induce more posttranslational modifications in the fibrinogen structure than the weaker ones, and they extensively alter the architecture of the fibrin network. Molecular dynamics simulations revealed that the effect of posttranslational modifications on fibrinogen secondary structure varies from negligible alternations to serious disruptions. Among the serious disruptions is the oxidation of γR375 resulting in the release of Ca2+ ion that is necessary for appropriate fibrin fiber formation. Folding of amino acids γE72-γN77 into a short α-helix is a result of oxidation of γP76 to glutamic acid. The study describes behaviour of fibrinogen coiled-coil connecter in the vicinity of plasmin and hementin cleavage sites.
- MeSH
- epitopy MeSH
- fibroblasty MeSH
- interferony imunologie klasifikace MeSH
- kyseliny MeSH
- leukocyty MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
BACKGROUND: Type I restriction-modification (R-M) systems are the most complex restriction enzymes discovered to date. Recent years have witnessed a renaissance of interest in R-M enzymes Type I. The massive ongoing sequencing programmes leading to discovery of, so far, more than 1 000 putative enzymes in a broad range of microorganisms including pathogenic bacteria, revealed that these enzymes are widely represented in nature. The aim of this study was characterisation of a putative R-M system EcoA0ORF42P identified in the commensal Escherichia coli A0 34/86 (O83: K24: H31) strain, which is efficiently used at Czech paediatric clinics for prophylaxis and treatment of nosocomial infections and diarrhoea of preterm and newborn infants. RESULTS: We have characterised a restriction-modification system EcoA0ORF42P of the commensal Escherichia coli strain A0 34/86 (O83: K24: H31). This system, designated as EcoAO83I, is a new functional member of the Type IB family, whose specificity differs from those of known Type IB enzymes, as was demonstrated by an immunological cross-reactivity and a complementation assay. Using the plasmid transformation method and the RM search computer program, we identified the DNA recognition sequence of the EcoAO83I as GGA(8N)ATGC. In consistence with the amino acids alignment data, the 3' TRD component of the recognition sequence is identical to the sequence recognized by the EcoEI enzyme. The A-T (modified adenine) distance is identical to that in the EcoAI and EcoEI recognition sites, which also indicates that this system is a Type IB member. Interestingly, the recognition sequence we determined here is identical to the previously reported prototype sequence for Eco377I and its isoschizomers. CONCLUSION: Putative restriction-modification system EcoA0ORF42P in the commensal Escherichia coli strain A0 34/86 (O83: K24: H31) was found to be a member of the Type IB family and was designated as EcoAO83I. Combination of the classical biochemical and bacterial genetics approaches with comparative genomics might contribute effectively to further classification of many other putative Type-I enzymes, especially in clinical samples.
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- DNA restrikčně-modifikační enzymy genetika metabolismus MeSH
- Escherichia coli enzymologie genetika MeSH
- financování organizované MeSH
- genomika MeSH
- proteiny z Escherichia coli genetika metabolismus MeSH
- protilátky bakteriální metabolismus MeSH
- restrikční endonukleasy typu I genetika metabolismus MeSH
- sekvence nukleotidů MeSH
- sekvenční homologie nukleových kyselin MeSH
- sekvenční seřazení MeSH
- testy genetické komplementace MeSH
Y-shaped molecules bearing alkynylallylic moieties were found to be potent and selective PPARdelta activators. The alkynylallylic moiety was synthesized from alkyn-1-ols by hydroalumination followed by a cross-coupling reaction. Series of active compounds 6 were obtained by stepwise changing the structure of the known PPARpan agonist 5 into Y-shaped compounds. The most active and selective compound, 6f, had a PPARdelta potency of 0.13 microM, which is 50-fold more potent than compound 5.
Restriction-modification systems protect bacteria from foreign DNA. Type I restriction-modification enzymes are multifunctional heteromeric complexes with DNA-cleavage and ATP-dependent DNA translocation activities located on endonuclease/motor subunit HsdR. The recent structure of the first intact motor subunit of the type I restriction enzyme from plasmid EcoR124I suggested a mechanism by which stalled translocation triggers DNA cleavage via a lysine residue on the endonuclease domain that contacts ATP bound between the two helicase domains. In the present work, molecular dynamics simulations are used to explore this proposal. Molecular dynamics simulations suggest that the Lys-ATP contact alternates with a contact with a nearby loop housing the conserved QxxxY motif that had been implicated in DNA cleavage. This model is tested here using in vivo and in vitro experiments. The results indicate how local interactions are transduced to domain motions within the endonuclease/motor subunit.
- MeSH
- adenosintrifosfát chemie metabolismus MeSH
- aminokyselinové motivy MeSH
- DNA chemie metabolismus MeSH
- fenotyp MeSH
- genotyp MeSH
- hydrolýza MeSH
- katalýza MeSH
- kinetika MeSH
- konzervovaná sekvence MeSH
- kvantová teorie MeSH
- lysin MeSH
- mutace MeSH
- mutageneze cílená MeSH
- restrikční endonukleasy typu I chemie genetika metabolismus MeSH
- simulace molekulární dynamiky MeSH
- terciární struktura proteinů MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
The connection of two active molecules across an easily released bridge as a new type of potentially active molecule has been studied. The synthesis is based on derivatives that originate from isonicotinoyl hydrazide, pyrazinamide, p-aminosalicylic acid (PAS), ethambutol, and ciprofloxacin. The lipophilicity, hydrolysis (stability of the compounds), and antituberculotic activity as well as the structure-lipophilicity and structure-activity relationships are discussed.
- MeSH
- antituberkulotika farmakologie chemická syntéza chemie MeSH
- chemické jevy MeSH
- financování organizované MeSH
- fyzikální chemie MeSH
- isoniazid farmakologie chemická syntéza MeSH
- kinetika MeSH
- kvantitativní vztahy mezi strukturou a aktivitou MeSH
- lipidy chemie MeSH
- mikrobiální testy citlivosti MeSH
- Mycobacterium avium účinky léků MeSH
- Mycobacterium kansasii účinky léků MeSH
- poločas MeSH
- pyrazinamid farmakologie chemická syntéza MeSH
- vysokoúčinná kapalinová chromatografie MeSH
