1,721,113 research outputs found
Growth and organization of Langmuir-Blodgett protein crystals via in situ GISAXS, laser-microdissection, nanodiffraction, Raman spectroscopy and atomic force microscopy
No full textIn situ microGISAXS: I. Experimental setup for submicron study of protein nucleation and growth
No full textIn this study, we used microbeam grazing-incidence small-angle x-ray scattering (mGISAXS) to investigate in situ protein nucleation and crystal growth assisted by a protein nanotemplate, and introduced certain innovations to improve the method. Our aim was to understand the protein nanotemplate method in detail, as this method has been shown to be capable of accelerating and increasing crystal size and quality, as well as inducing crystallization of proteins that are not crystallizable by classical methods. The nanotemplate experimental setup was used for drops containing growing protein crystals at different stages of nucleation and growth. Two model proteins, lysozyme and thaumatin, were used under unique flow conditions to differentially probe protein crystal nucleation and growth
Langmuir-blodgett nanotemplate crystallization combined to lasermicrofragmentation uniquely characterize proteins crystals by synchrotron microdiffraction
No full textLaser-induced microfragmentation of LB nanotemplate-induced protein crystals in glycerol solution results in distinct, coherently diffracting domains. Only crystals produced according to the Langmuir-Blodgett (LB) nanotemplate technique reveal in all four proteins being tested (lysozyme, insulin, thaumatin and ribonuclease) domains highly radiation resistant, while the crystals produced by the standard hanging drop crystallization method do not. Actually the very same laser exposure causes the disappearance of these "classical" protein crystals during the same time frame of 40 min needed for the laser cutting in all four proteins being tested. The microdiffraction of microcrystals prepered by the combination of Langmuir- Blodgett and Laser technologies proves that not only the Lysozyme survives the process, as shown recently by nanodifraction, but also all three other model proteins appear to behave similarly well, namely insulin, thaumatin and ribonuclease. The result confirms the emerging of a new biophysical technique uniquely usefull for synchrotron radiation studies based on small protein microcrystals uniquely radiation resistant when prepered by LB nanotemplate and subsequently fragmented by Laser
Surveying silk fibre degradation by crystallinity determination: a study on the Tang-Dynasty silk treasure from Famen temple, China
No full textEmergence of amyloidic fibrillation in 2D-ordered Langmuir-Blodgett protein multilayers upon heating
No full textLangmuir-Blodgett protein nanofilms can serve as templates for nucleation and growth of protein crystals. This functionality can be enhanced by thermal annealing. While surface ordering of the multilayered nanofilms and an improvement of the correlation between the layers during thermal annealing have been revealed by atomic force microscopy and grazing-incidence small-angle X-ray scattering, information on the structure developing in the bulk of nanofilms is lacking. In this paper, we report on scanning X-ray nanodiffraction experiments of penicillin-G-acylase multilayers deposited on Si3N4 membranes and annealed at 150 °C. While the annealed multilayer has remained mostly featureless, we observe locally globular aggregates and filamentous spherulites based on nanofibrillar subunits with cross-β amyloidic motifs
Two-dimensional x-ray waveguides and point sources
No full textWe show that resonant coupling of synchrotron beams into suitable nanostructures can be used for the generation of coherent x-ray point sources. A two-dimensionally con ning x-ray waveguide structure has been fabricated by e-beam lithography. By shining a parallel undulator beam onto the structure, a discrete set of resonant modes can be excited in the dielectric cavity, depending on the two orthogonal coupling angles between the beam and the waveguide interfaces. The resonant excitation of the modes is evidenced from the characteristic set of coupling angles as well as the observed far-field pattern. The x-ray nanostructure may be used as coherent x-ray point sources with a beam cross section in the nanometer range
Radiation stability of protein crystals grown by nanostructured templates: synchrotron microfocus analysis
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