Introduction: Zika Virus (ZIKV) infection is a major public health concern, affecting almost each country in the western hemisphere. A more than 20-fold increase in microcephaly risks is associated to ZIKV infection in pregnancy. A new vaccine is not expected before 2019, and alternative prophylactic and therapeutic approaches are encouraged. We expect that the Resonant Recognition Model, developed by Irena Cosic, might lay on the basis for an alternative approach to handle ZIKV. Objective: We tried to identify the resonant frequencies associated to the ZIKV polyprotein and their use for an automatic taxonomy of different ZIKV strains. We put to test the hypothesis of interaction between ZIKV envelope protein and the AXL receptor, one of the plausible mechanisms proposed for ZIKV associated microcephaly. Results: Four relevant frequencies (fRRM) were found in ZIKV polyprotein consensus spectrum. Corresponding four spectral amplitudes allowed separating African from Asian/American ZIKV isolates (k-means clustering). Peak 3 (fRRM= 0.2754) and Peak 4 (fRRM= 0.334) yielded a finer separation between Asian sequences and those from the current outbreak collected in 2015 (Asian/American). Consensus spectrum for pooled Dengue virus and ZIKV polyprotein sequences suggest that Peak 4 might be a specific hallmark of ZIKV. RRM results support the interaction between ZIKV envelope protein and AXL membrane receptor. The interacting frequency of fRRM= 0.167 seems to be a sub-harmonic of Peak 4. Conclusions: Resonant recognition model provides a plausible view of processes involved in the interactions of ZIKV with the human host, and is suggesting the exchange of electromagnetic radiation at the frequencies of 601.8nm (yellow light) and 1203.6 (near infrared) during ZIKV envelope protein with the AXL receptor in the human fetal tissue. This information might be relevant for alternative approaches to new therapeutic approaches to treat ZIKV-associated damage to newborns.

• Klíčová slova
• electron-ion interaction potential,
• MeSH
• elektromagnetické jevy MeSH
• Flavivirus MeSH
• genové produkty env chemie   izolace a purifikace   MeSH
• infekce virem zika diagnóza   genetika   MeSH
• polyproteiny MeSH
• virus zika * chemie   genetika   klasifikace   MeSH

The combination of nanoparticles with the polymerase chain reaction (PCR) can have benefits such as easier sample handling or higher sensitivity, but also drawbacks such as loss of colloidal stability or inhibition of the PCR. The present work systematically investigates the interaction of magnetic iron oxide nanoparticles (MIONs) with the PCR in terms of colloidal stability and potential PCR inhibition due to interaction between the PCR components and the nanoparticle surface. Several types of MIONs with and without surface functionalisation by sodium citrate, dextran and 3-aminopropyl-triethoxysilane (APTES) were prepared and characterised by Transmission Electron Microscopy (TEM), dynamic light scattering (DLS) and Fourier Transform Infrared (FT-IR) spectroscopy. Colloidal stability in the presence of the PCR components was investigated both at room temperature and under PCR thermo-cycling. Dextran-stabilized MIONs show the best colloidal stability in the PCR mix at both room and elevated temperatures. Citrate- and APTES-stabilised as well as uncoated MIONs show a comparable PCR inhibition near the concentration 0.1mgml(-1) while the inhibition of dextran stabilized MIONs became apparent near 0.5mgml(-1). It was demonstrated that the PCR could be effectively carried out even in the presence of elevated concentration of MIONs up to 2mgml(-1) by choosing the right coating approach and supplementing the reaction mix by critical components, Taq DNA polymerase and Mg(2+) ions.

• MeSH
• citráty chemie   MeSH
• dextrany chemie   MeSH
• koloidy chemie   MeSH
• nanočástice chemie   MeSH
• polymerázová řetězová reakce * MeSH
• povrchové vlastnosti MeSH
• propylaminy chemie   MeSH
• silany chemie   MeSH
• teplota MeSH
• velikost částic MeSH
• železité sloučeniny chemie   MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Cellobiose dehydrogenase (CDH) is a fungal extracellular oxidoreductase which fuels lytic polysaccharide monooxygenase with electrons during cellulose degradation. Interdomain electron transfer between the flavin and cytochrome domain in CDH, preceding the electron flow to lytic polysaccharide monooxygenase, is known to be pH dependent, but the exact mechanism of this regulation has not been experimentally proven so far. METHODS: To investigate the structural aspects underlying the domain interaction in CDH, hydrogen/deuterium exchange (HDX-MS) with improved proteolytic setup (combination of nepenthesin-1 with rhizopuspepsin), native mass spectrometry with ion mobility and electrostatics calculations were used. RESULTS: HDX-MS revealed pH-dependent changes in solvent accessibility and hydrogen bonding at the interdomain interface. Electrostatics calculations identified these differences to result from charge neutralization by protonation and together with ion mobility pointed at higher electrostatic repulsion between CDH domains at neutral pH. In addition, we uncovered extensive O-glycosylation in the linker region and identified the long-unknown exact cleavage point in papain-mediated domain separation. CONCLUSIONS: Transition of CDH between its inactive (open) and interdomain electron transfer-capable (closed) state is shown to be governed by changes in the protein surface electrostatics at the domain interface. Our study confirms that the interdomain electrostatic repulsion is the key factor modulating the functioning of CDH. GENERAL SIGNIFICANCE: The results presented in this paper provide experimental evidence for the role of charge repulsion in the interdomain electron transfer in cellobiose dehydrogenases, which is relevant for exploiting their biotechnological potential in biosensors and biofuel cells.

• MeSH
• celobiosa metabolismus   MeSH
• cytochromy metabolismus   MeSH
• deuterium metabolismus   MeSH
• elektrony MeSH
• flaviny metabolismus   MeSH
• fungální proteiny metabolismus   MeSH
• glykosylace MeSH
• houby metabolismus   MeSH
• karbohydrátdehydrogenasy metabolismus   MeSH
• koncentrace vodíkových iontů MeSH
• oxygenasy se smíšenou funkcí metabolismus   MeSH
• polysacharidy metabolismus   MeSH
• proteinové domény MeSH
• proteolýza MeSH
• sekvence aminokyselin MeSH
• statická elektřina MeSH
• transport elektronů fyziologie   MeSH
• vodík metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Development of multifunctional nanoscale sensors working under physiological conditions enables monitoring of intracellular processes that are important for various biological and medical applications. By attaching paramagnetic gadolinium complexes to nanodiamonds (NDs) with nitrogen-vacancy (NV) centres through surface engineering, we developed a hybrid nanoscale sensor that can be adjusted to directly monitor physiological species through a proposed sensing scheme based on NV spin relaxometry. We adopt a single-step method to measure spin relaxation rates enabling time-dependent measurements on changes in pH or redox potential at a submicrometre-length scale in a microfluidic channel that mimics cellular environments. Our experimental data are reproduced by numerical simulations of the NV spin interaction with gadolinium complexes covering the NDs. Considering the versatile engineering options provided by polymer chemistry, the underlying mechanism can be expanded to detect a variety of physiologically relevant species and variables.

• MeSH
• biosenzitivní techniky metody   MeSH
• časové faktory MeSH
• koncentrace vodíkových iontů MeSH
• konfokální mikroskopie MeSH
• kvantová teorie MeSH
• nanodiamanty chemie   ultrastruktura   MeSH
• nanotechnologie metody   MeSH
• optické zobrazování metody   MeSH
• oxidace-redukce MeSH
• reprodukovatelnost výsledků MeSH
• transmisní elektronová mikroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Phosphoinositides are glycerol-based phospholipids, and they play essential roles in cellular signalling, membrane and cytoskeletal dynamics, cell movement, and the modulation of ion channels and transporters. Phosphoinositides are also associated with fundamental nuclear processes through their nuclear protein-binding partners, even though membranes do not exist inside of the nucleus. Phosphatidylinositol 4-phosphate (PI(4)P) is one of the most abundant cellular phosphoinositides; however, its functions in the nucleus are still poorly understood. In this study, we describe PI(4)P localisation in the cell nucleus by super-resolution light and electron microscopy, and employ immunoprecipitation with a specific anti-PI(4)P antibody and subsequent mass spectrometry analysis to determine PI(4)P's interaction partners. We show that PI(4)P is present at the nuclear envelope, in nuclear lamina, in nuclear speckles and in nucleoli and also forms multiple small foci in the nucleoplasm. Nuclear PI(4)P undergoes re-localisation to the cytoplasm during cell division; it does not localise to chromosomes, nucleolar organising regions or mitotic interchromatin granules. When PI(4)P and PI(4,5)P2 are compared, they have different nuclear localisations during interphase and mitosis, pointing to their functional differences in the cell nucleus. Mass spectrometry identified hundreds of proteins, including 12 potentially novel PI(4)P interactors, most of them functioning in vital nuclear processes such as pre-mRNA splicing, transcription or nuclear transport, thus extending the current knowledge of PI(4)P's interaction partners. Based on these data, we propose that PI(4)P also plays a role in essential nuclear processes as a part of protein-lipid complexes. Altogether, these observations provide a novel insight into the role of PI(4)P in nuclear functions and provide a direction for further investigation.

• MeSH
• buněčné jadérko metabolismus   ultrastruktura   MeSH
• buněčné jádro metabolismus   ultrastruktura   MeSH
• buněčný cyklus MeSH
• fosfatidylinositolfosfáty metabolismus   MeSH
• jaderné proteiny metabolismus   MeSH
• jaderný obal metabolismus   ultrastruktura   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• proteom metabolismus   MeSH
• shluková analýza MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Our understanding of the general principles of the polymodal regulation of transient receptor potential (TRP) ion channels has grown impressively in recent years as a result of intense efforts in protein structure determination by cryo-electron microscopy. In particular, the high-resolution structures of various TRP channels captured in different conformations, a number of them determined in a membrane mimetic environment, have yielded valuable insights into their architecture, gating properties and the sites of their interactions with annular and regulatory lipids. The correct repertoire of these channels is, however, organized by supramolecular complexes that involve the localization of signaling proteins to sites of action, ensuring the specificity and speed of signal transduction events. As such, TRP ankyrin 1 (TRPA1), a major player involved in various pain conditions, localizes into cholesterol-rich sensory membrane microdomains, physically interacts with calmodulin, associates with the scaffolding A-kinase anchoring protein (AKAP) and forms functional complexes with the related TRPV1 channel. This perspective will contextualize the recent biochemical and functional studies with emerging structural data with the aim of enabling a more thorough interpretation of the results, which may ultimately help to understand the roles of TRPA1 under various physiological and pathophysiological pain conditions. We demonstrate that an alteration to the putative lipid-binding site containing a residue polymorphism associated with human asthma affects the cold sensitivity of TRPA1. Moreover, we present evidence that TRPA1 can interact with AKAP to prime the channel for opening. The structural bases underlying these interactions remain unclear and are definitely worth the attention of future studies.

• Publikační typ
• časopisecké články MeSH

Kondagogu (Cochlospermum gossypium) gum (KG), a natural tree exudate, was investigated for its morphological, adsorption and metal interaction behavior with various toxic heavy metals (Pb, Cd, Ni, Cr and Fe). SEM, AFM and TEM techniques were used to study the morphological changes occurring after metal adsorption onto the biopolymer structure. The degree of biosorption of metals on KG biopolymer surfaces was assessed by small-angle X-ray scattering analysis. EDXA spectrum revealed that the ion-exchange mechanism plays a major role in the binding process between KG and metal ions. The higher electron density observed in the KG-Cd complex suggests that Cd is strongly bound to KG compared to the other metals. This work provides a potential platform for developing a hydrocolloid-based nanogel for bioremediation of environmental contaminants.

• MeSH
• adsorpce MeSH
• biodegradace MeSH
• biopolymery chemie   MeSH
• Bixaceae chemie   MeSH
• iontová výměna MeSH
• koloidy chemie   MeSH
• komplexní sloučeniny chemie   MeSH
• polyethylenglykoly chemie   MeSH
• polyethylenimin chemie   MeSH
• rostlinné extrakty chemie   MeSH
• těžké kovy chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Understanding interactions of calcium with lipid membranes at the molecular level is of great importance in light of their involvement in calcium signaling, association of proteins with cellular membranes, and membrane fusion. We quantify these interactions in detail by employing a combination of spectroscopic methods with atomistic molecular dynamics simulations. Namely, time-resolved fluorescent spectroscopy of lipid vesicles and vibrational sum frequency spectroscopy of lipid monolayers are used to characterize local binding sites of calcium in zwitterionic and anionic model lipid assemblies, while dynamic light scattering and zeta potential measurements are employed for macroscopic characterization of lipid vesicles in calcium-containing environments. To gain additional atomic-level information, the experiments are complemented by molecular simulations that utilize an accurate force field for calcium ions with scaled charges effectively accounting for electronic polarization effects. We demonstrate that lipid membranes have substantial calcium-binding capacity, with several types of binding sites present. Significantly, the binding mode depends on calcium concentration with important implications for calcium buffering, synaptic plasticity, and protein-membrane association.

• MeSH
• buněčná membrána metabolismus   MeSH
• fosfolipidy chemie   metabolismus   MeSH
• lipidové dvojvrstvy chemie   metabolismus   MeSH
• liposomy chemie   metabolismus   MeSH
• molekulární modely MeSH
• simulace molekulární dynamiky MeSH
• vápník metabolismus   MeSH
• vápníková signalizace MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

Present study describes the preparation of a polyethylene glycol-grafted oxidized multi-walled carbon nanotubes (oMWCNTs-PEG) hybrid nanosystem as a carrier of etoposide (VP-16) and Bcl-2 phosphorothioate antisense deoxyoligonucleotides (Aso) to achieve a superior cytostastic efficacy in non-small and small cell lung cancer in vitro. We have demonstrated that the adsorption of hydrophobic VP-16 and Bcl-2 Aso results in a stable nanotransporter exhibiting good dispersion with excellent release profiles (both, in pH 7.4 and 4.8) and negligible hemolytic activity (up to 6.5%). The evaluation of cytotoxicity was carried out in in vitro using small cell (SCLC; DMS53) and non-small cell lung cancer (NSCLC; NCIH2135) cell lines. It was found that Bcl-2 interference significantly increased the anti-cancer efficiency of VP-16 in the chemoresistant NSCLC cells. This was further supported using a flow-cytometry (Annexin V/propidium iodide assay), which revealed a significant increase in apoptotic cells in both the cell lines after the co-administration of VP-16 and Bcl-2 Aso using oMWCNTs-PEG hybrid, and fluorescence microscopy, which showed an increase in reactive oxygen species identified after Bcl-2 knock-down. Overall, oMWCNTs-PEG provided an exceptional biocompatible vehicle enabling the internalization of negatively charged nucleic acids and pH-sensitive release of cargoes in a hypoxic environment of the most of solid tumors. Moreover, Aso specifically binding to the first six codons of the Bcl-2 mRNA gave a satisfactorily decrease in Bcl-2 translation and an increase in NCIH2135 chemosensitivity towards VP-16.

• MeSH
• antisense oligonukleotidy chemie   MeSH
• antitumorózní látky aplikace a dávkování   MeSH
• apoptóza MeSH
• biokompatibilní materiály chemie   MeSH
• elektroforéza MeSH
• erytrocyty cytologie   MeSH
• etoposid aplikace a dávkování   MeSH
• hemolýza MeSH
• hydrofobní a hydrofilní interakce MeSH
• hypoxie buňky MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• malobuněčný karcinom plic metabolismus   patologie   MeSH
• mikroskopie elektronová rastrovací MeSH
• nádorové buněčné linie účinky léků   MeSH
• nádory plic metabolismus   patologie   MeSH
• nanotrubičky uhlíkové chemie   MeSH
• nemalobuněčný karcinom plic metabolismus   patologie   MeSH
• nosiče léků MeSH
• nukleové kyseliny chemie   MeSH
• oligonukleotidy chemie   MeSH
• polyethylenglykoly chemie   MeSH
• protoonkogenní proteiny c-bcl-2 genetika   MeSH
• průtoková cytometrie MeSH
• reaktivní formy kyslíku chemie   MeSH
• synergismus léků MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH