Nejvíce citovaný článek - PubMed ID 2675315
The combination of low-temperature scanning tunnelling microscopy with a mass-selective electro-spray ion-beam deposition established the investigation of large biomolecules at nanometer and sub-nanometer scale. Due to complex architecture and conformational freedom, however, the chemical identification of building blocks of these biopolymers often relies on the presence of markers, extensive simulations, or is not possible at all. Here, we present a molecular probe-sensitisation approach addressing the identification of a specific amino acid within different peptides. A selective intermolecular interaction between the sensitiser attached at the tip-apex and the target amino acid on the surface induces an enhanced tunnelling conductance of one specific spectral feature, which can be mapped in spectroscopic imaging. Density functional theory calculations suggest a mechanism that relies on conformational changes of the sensitiser that are accompanied by local charge redistributions in the tunnelling junction, which, in turn, lower the tunnelling barrier at that specific part of the peptide.
The science of X-ray free-electron lasers (XFELs) critically depends on the performance of the X-ray laser and on the quality of the samples placed into the X-ray beam. The stability of biological samples is limited and key biomolecular transformations occur on short timescales. Experiments in biology require a support laboratory in the immediate vicinity of the beamlines. The XBI BioLab of the European XFEL (XBI denotes XFEL Biology Infrastructure) is an integrated user facility connected to the beamlines for supporting a wide range of biological experiments. The laboratory was financed and built by a collaboration between the European XFEL and the XBI User Consortium, whose members come from Finland, Germany, the Slovak Republic, Sweden and the USA, with observers from Denmark and the Russian Federation. Arranged around a central wet laboratory, the XBI BioLab provides facilities for sample preparation and scoring, laboratories for growing prokaryotic and eukaryotic cells, a Bio Safety Level 2 laboratory, sample purification and characterization facilities, a crystallization laboratory, an anaerobic laboratory, an aerosol laboratory, a vacuum laboratory for injector tests, and laboratories for optical microscopy, atomic force microscopy and electron microscopy. Here, an overview of the XBI facility is given and some of the results of the first user experiments are highlighted.
- Klíčová slova
- European XFEL (EuXFEL), XBI Laboratory, coherent diffractive imaging (CDI), free-electron lasers (XFELs), sample preparation and characterization, serial femtosecond crystallography (SFX), single-particle imaging (SPI), structural biology, time-resolved experiments,
- Publikační typ
- časopisecké články MeSH
The possibility of imaging single proteins constitutes an exciting challenge for x-ray lasers. Despite encouraging results on large particles, imaging small particles has proven to be difficult for two reasons: not quite high enough pulse intensity from currently available x-ray lasers and, as we demonstrate here, contamination of the aerosolized molecules by nonvolatile contaminants in the solution. The amount of contamination on the sample depends on the initial droplet size during aerosolization. Here, we show that, with our electrospray injector, we can decrease the size of aerosol droplets and demonstrate virtually contaminant-free sample delivery of organelles, small virions, and proteins. The results presented here, together with the increased performance of next-generation x-ray lasers, constitute an important stepping stone toward the ultimate goal of protein structure determination from imaging at room temperature and high temporal resolution.
Multiple myeloma (MM) is an incurable plasma cell (PC) malignancy characterized by the accumulation of monoclonal PCs in the bone marrow. For deeper understanding of the molecular mechanisms involved in the development of this disease, the influence of microenvironment, or the prediction of response of tumor PCs to anti-MM treatment, it is possible to use modern technologies for genomic and proteomic analyses. Due to progress in instrumentation, one of the main tools of proteomic analysis is mass spectrometry in combination with chosen separation techniques. This review will provide a short survey of the most commonly used proteomic techniques and show examples of their applications in MM proteome studies.
- MeSH
- biologické markery * MeSH
- hmotnostní spektrometrie * MeSH
- kostní dřeň metabolismus MeSH
- mnohočetný myelom patologie MeSH
- plazmatické buňky patologie MeSH
- proteom genetika MeSH
- proteomika metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- biologické markery * MeSH
- proteom MeSH
