surface complexation
Dotaz
Zobrazit nápovědu
Cells communicate with their environment via surface receptors, but nanoscopic receptor organization with respect to complex cell surface morphology remains unclear. This is mainly due to a lack of accessible, robust and high-resolution methods. Here, we present an approach for mapping the topography of receptors at the cell surface with nanometer precision. The method involves coating glass coverslips with glycine, which preserves the fine membrane morphology while allowing immobilized cells to be positioned close to the optical surface. We developed an advanced and simplified algorithm for the analysis of single-molecule localization data acquired in a biplane detection scheme. These advancements enable direct and quantitative mapping of protein distribution on ruffled plasma membranes with near isotropic 3D nanometer resolution. As demonstrated successfully for CD4 and CD45 receptors, the described workflow is a straightforward quantitative technique to study molecules and their interactions at the complex surface nanomorphology of differentiated metazoan cells.
- MeSH
- buněčná membrána metabolismus MeSH
- nanotechnologie * MeSH
- receptory buněčného povrchu * metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In this study, the importance of Sb behavior under different pH conditions has been addressed with respect to its stabilization in aqueous solutions using Mg-Fe layered double hydroxides (LDHs). The Sb(V) adsorption onto Mg-Fe LDHs was performed at different initial Sb(V) concentrations and pH values (pH 5.5, 6.5 and 7.5). The removal rate and the maximal adsorbed amount increased with decreasing pH values. Moreover, the surface complexation modeling (SCM) predicted preferable formation of monodentate mononuclear and bidentate binuclear complexes on the Mg-Fe LDH surface. Spectroscopic (X-ray diffraction analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy) and microscopic (scanning electron microscopy and energy-dispersive X-ray spectroscopy) techniques were used to further specify the adsorption mechanisms. The influence of chemical adsorption, surface-induced precipitation of brandholzite Mg[Sb(OH)6]2·6H2O, formation of brandholzite-like phases and/or anion exchange was observed. Moreover, Sb(V) was nonhomogeneously distributed on the Mg-Fe LDH surface at all pH values. The surface complexation modeling supported by solid-state analyses provided a strong tool to investigate the binding arrangements of Sb(V) on the Mg-Fe LDH surface. Such a complex mechanistic/modeling approach has not previously been presented and enables prediction of the Sb(V) adsorption behavior onto Mg-Fe LDHs under different conditions, evaluating their possible use in actual applications.
Študovali sme vplyv troch komplexných médií (KM) [Muellerov-Hintonov bujón (MHB), mozgovosrdcováinfúzia (MSI) a proteózový peptón (PP)] a jedného minerálneho (MM) na povrchové a enzymatickéaktivity 5 kmeňov Klebsiella species. Klebsiella oxytoca a Klebsiella ornithinolytica savyznačovali značným hydrofóbnym charakterom po raste v MHB, MSI a MM, Klebsiella terrigenalen v PP. K. oxytoca a K. ornithinolytica po kultivácii v KM prejavili väčšiu motilitu ako v MM,motilita kmeňov K. terrigena nebola ovplyvnená. Lipolytická aktivita u všetkých testovanýchkmeňov bola najvyššia po raste v MSI a PP. Zloženie kultivačného média ovplyvnilo sledovanébakteriálne parametre v rôznom rozsahu v závislosti na species.
The effect of three complex media (KM) [Mueller-Hinton broth (MHB), brain heart infusion (MSI)and proteose peptone (PP)] and one mineral medium (MM) on surface and enzyme activities of fivestrains Klebsiella species was studied. Klebsiella oxytoca and Klebsiella ornithinolytica had a markedhydrophobic character after growth in MHB, MSI and MM, Klebsiella terrigena only in PP. K.oxytoca and K. ornithinolytica had a higher motility after cultivation in KM compared with MM, themotility of K. terrigena was not affected. The lipolytic activity of all tested strains was highest aftergrowth in MSI and PP. The composition of culture medium affected bacterial parameters tested toa different extent depending on the species.
... Two Like Surfaces Coming Together in a Medium: -- Surface and Interfacial Energy 196 -- 10.3. ... ... Particle-Surface Interactions 259 -- 13.5. ... ... Surface and Adhesion Energies 275 -- 13.14. Surface Energies of Metals 280 -- 13.15. ... ... Surface Charge, Electric Field, and Counterion -- Concentration at a Surface: “Contact” Values 294 -- ... ... Surface Charge and Potential of Isolated Surfaces 309 -- 14.13. ...
Third edition xxx, 674 stran : 24 cm il. ;
- MeSH
- fyzikální chemie MeSH
- Publikační typ
- monografie MeSH
- Konspekt
- Fyzikální chemie
- NLK Obory
- chemie, klinická chemie
Cell surface proteins are major targets of biomedical research due to their utility as cellular markers and their extracellular accessibility for pharmacological intervention. However, information about the cell surface protein repertoire (the surfaceome) of individual cells is only sparsely available. Here, we applied the Cell Surface Capture (CSC) technology to 41 human and 31 mouse cell types to generate a mass-spectrometry derived Cell Surface Protein Atlas (CSPA) providing cellular surfaceome snapshots at high resolution. The CSPA is presented in form of an easy-to-navigate interactive database, a downloadable data matrix and with tools for targeted surfaceome rediscovery (http://wlab.ethz.ch/cspa). The cellular surfaceome snapshots of different cell types, including cancer cells, resulted in a combined dataset of 1492 human and 1296 mouse cell surface glycoproteins, providing experimental evidence for their cell surface expression on different cell types, including 136 G-protein coupled receptors and 75 membrane receptor tyrosine-protein kinases. Integrated analysis of the CSPA reveals that the concerted biological function of individual cell types is mainly guided by quantitative rather than qualitative surfaceome differences. The CSPA will be useful for the evaluation of drug targets, for the improved classification of cell types and for a better understanding of the surfaceome and its concerted biological functions in complex signaling microenvironments.
- MeSH
- buněčné linie MeSH
- databáze proteinů MeSH
- hmotnostní spektrometrie metody MeSH
- lidé MeSH
- membránové proteiny chemie MeSH
- myši MeSH
- proteomika metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Úvod: Protilátky proti membránovým a synaptickým antigenům jsou přímo patogenní protilátky sdružené s pestrou paletou neurologických syndromů. Různorodost příznaků komplikuje stanovení diagnózy, a tím i včasné zahájení imunoterapie. Cíl: Cílem práce bylo popsat klinické charakteristiky pacientů s pozitivitou uvedených protilátek. Metodika a soubor: V období dvou let jsme zjišťovali přítomnost protilátek proti membránovým a synaptickým antigenům u 224 pacientů. Metodou nepřímé imunofluorescence byly vyšetřeny protilátky proti N‑metyl‑D‑aspartátovému receptoru (anti‑NMDAR), α‑amino‑3-hydroxy‑5-metyl‑4-izoxazolepropionátovému receptoru (anti‑AMPAR 1 a 2), B‑receptoru kyseliny γ‑aminomáselné (anti‑GABABR), proti leucin‑rich‑glioma‑inactivated proteinu‑1 (anti‑LGI1) a proti contactin‑associated proteinu‑2 (anti‑CASPR2). U pozitivních pacientů byly retrospektivně zhodnoceny klinické projevy, nálezy pomocných metod a vývoj onemocnění. Pacienti s pozitivitou anti‑NMDAR protilátek nebyli do hodnocení zahrnuti. Výsledky: Autoprotilátky byly prokázány v séru 11 pacientů (medián 58 let, sedm mužů) – u šesti pacientů anti‑LGI1, u čtyř anti‑CASPR2, u dvou anti‑AMPAR1 (u jednoho pacienta současně anti‑AMPAR1 a anti‑CASPR2). Příznaky zahrnovaly epilepsii (n = 5), subakutní encefalopatii (n = 5), doprovázenou ve čtyřech případech epileptickými záchvaty, a mozečkový syndrom s doprovodným kognitivním deficitem (n = 1). U dvou pacientů byly současně přítomny dobře charakterizované onkoneurální protilátky (anti‑Hu, anti‑Ma2). Nádor (malobuněčný karcinom plic) byl zjištěn u jedné pacientky (anti‑AMPAR1). U osmi pacientů došlo po podání imunosuprese k remisi nebo částečnému zlepšení klinického stavu. Závěr: Přítomnost protilátek proti membránovým antigenům je sdružena nejčastěji s limbickou encefalitidou nebo fokální epilepsií, vzácněji s jinými neurologickými syndromy. Efekt imunoterapie závisí na jejím časném podání.
Background: Neuronal surface antibodies are associated with numerous neurological symptoms. Better knowledge of these symptoms may improve identification of potential candidates for immunotherapy. Aim: Characterize clinical signs in patients with neuronal surface antibodies positivity. Methods: We detected neuronal surface antibodies in 11/2011–12/2013 in 224 patients (224 in serum and 37 in cerebrospinal fluid). We investigated anti-NMDAR, anti-AMPAR1, anti-AMPAR2, anti-GABABR, anti-LGI1, anti-CASPR2 using cell-based assays for indirect immunofluorescence (Euroimmun AG). We retrospectively analyzed clinical characteristics of patients with positive neuronal surface antibodies in serum or cerebrospinal fluid other than anti-NMDAR positive patients. Results: Neuronal surface antibodies were detected in 11 patients (seven males, median age 58). Six patients had anti-LGI1, four anti-CASPR2 and two anti-AMPAR1 antibodies (one patient had both anti-CASPR2 and anti-AMPAR1 antibodies). Clinical symptoms included chronic epilepsy (n = 5), acute encephalopathy (n = 5) accompanied by epileptic seizures in four patients and one patient presented with cerebellar syndrome and cognitive deficit. Two patients had coincidence of paraneoplastic antibodies (anti-Hu, anti-Ma2). Tumor (small cell lung carcinoma) was diagnosed in one patient (anti-AMPAR1). Eight patients improved following immunotherapy (corticosteroids, IVIG). Early immunotherapy was associated with better outcome. Conclusion: NS-Abs were mostly associated with limbic encephalitis and chronic temporal lobe epilepsy. Immunotherapy had better effect when applied early in the disease course. Key words: autoimmune diseases – encephalitis – antibodies to cell-surface proteins – limbic encephalitis The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE “uniform requirements” for biomedical papers.
- MeSH
- autoimunitní nemoci MeSH
- autoprotilátky * krev MeSH
- dospělí MeSH
- elektroencefalografie MeSH
- encefalitida s protilátkami proti NMDA receptorům krev MeSH
- epilepsie parciální diagnóza farmakoterapie MeSH
- fluorescenční protilátková technika nepřímá MeSH
- glutamátové receptory analýza MeSH
- imunosupresiva aplikace a dávkování MeSH
- kognitivní poruchy etiologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- limbická encefalitida * diagnóza farmakoterapie MeSH
- magnetická rezonanční tomografie MeSH
- membránové proteiny * krev MeSH
- mozek radiografie MeSH
- nemoci mozku * krev radiografie MeSH
- poruchy paměti etiologie MeSH
- proteiny nervové tkáně analýza MeSH
- proteiny analýza MeSH
- receptory GABA-B analýza MeSH
- receptory N-methyl-D-aspartátu analýza MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
We report an ultra-low fouling surface plasmon resonance imaging (SPRi) biosensor for the rapid simultaneous detection of multiple miRNAs in erythrocyte lysate (EL) at subpicomolar levels without need of RNA extraction. The SPRi chips were coated with ultra-low fouling functionalizable poly(carboxybetaine acrylamide) (pCBAA) brushes having optimized thicknesses and directly functionalized with amino-modified oligonucleotide probes. We have characterized the effect of the brush thickness on the probe loading capacity: a loading capacity of ~9.8×10(12) probes/cm(2) was achieved for pCBAA having a thickness of ~40 nm. The probe-functionalized sensor also exhibited a high resistance to fouling from ~90% EL samples (<2 ng/cm(2)). A two-step detection assay was employed for multiplexed miRNA detection in EL. Specifically, the assay consisted of (i) a sandwich-type hybridization of the probe-functionalized pCBAA with target miRNA in EL (bound to biotinylated oligonucleotides) and (ii) the capture of streptavidin-functionalized gold nanoparticles to the aforementioned biotinylated probes. We have demonstrated that this approach enables the detection of miRNAs in EL at concentrations as low as 0.5 pM. Finally, we have confirmed the detection of four endogenous miRNAs representing a set of potential miRNA biomarkers of myelodysplastic syndrome (MDS) in clinical EL samples (miR-16, miR-181, miR-34a, and miR-125b). The results revealed significantly higher levels of miR-16 in all the clinical EL samples compared to the other measured miRNAs.
- MeSH
- akrylamidy chemie MeSH
- analýza selhání vybavení MeSH
- biokompatibilní potahované materiály chemická syntéza MeSH
- biosenzitivní techniky přístrojové vybavení MeSH
- design vybavení MeSH
- frakcionace buněk MeSH
- komplexní směsi analýza MeSH
- mikro RNA analýza chemie genetika MeSH
- polymery chemie MeSH
- povrchová plasmonová rezonance přístrojové vybavení MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
