Ferroelectric-Specific Peptides as Building Blocks for Bio-Inorganic Devices

2006 ◽  
Vol 944 ◽  
Author(s):  
Brian Dennis Reiss ◽  
Leonidas Ocola ◽  
Orlando Auciello ◽  
Millicent A. Firestone

ABSTRACTThe integration of biomolecules with inorganic materials to create functional composites represents a critical step in the development of next-generation biosensors, micro/nanofluidic devices, and biochips that require a combination of abiotic (inorganics) and biotic (proteins, DNA, antibodies) components. Toward this end, we have previously applied combinatorial phage display techniques to identify a constrained heptapeptide sequence (CISLLHSTC) that selectively binds to a perovskite ferroelectric (MOCVD-deposited lead zirconium titanate, PZT). In this work, we examine the binding of this heptapeptide sequence, prepared by solid phase peptide synthesis to sol-gel PZT. In particular, the surface roughness has been examined and the long-term stability of the PZT films in biological buffered aqueous solutions by atomic force microscopy, X-ray diffraction and P-E hysteresis loop. In addition, the selectivity of the peptide binding to PZT has been determined by immunofluorescence microscopy and the nature of peptide binding to the PZT surface is probed by X-ray photoemission spectroscopy.

2020 ◽  
Author(s):  
Skander Abboud ◽  
Vincent AUCAGNE

An in-depth study of the Fmoc-based solid phase peptide synthesis of N-Hnb-Cys crypto-thioester peptides, advantageous building blocks for the native chemical ligation-based synthesis of proteins, led to the identification of epimerized and imidazolidinone side products formed during a key reductive amination step. The understanding of the underlying reaction mechanisms was crucial for the developement of an automatable optimized synthetic protocol.


2014 ◽  
Vol 21 (12) ◽  
pp. 1257-1264
Author(s):  
Stevenson Flemer

A proof-of-principle methodology is presented in which all commercially-available cysteine (Cys) and selenocysteine (Sec) solid phase peptide synthesis (SPPS) derivatives are synthesized in high yield from easily prepared protected dichalcogenide precursors. A Zn-mediated biphasic reduction process applied to a series of four bis-Nα-protected dichalcogenide compounds allows facile conversion to their corresponding thiol and selenol intermediates followed by insitu S- or Se-alkylation with various electrophiles to directly access twenty one known Cys and Sec SPPS derivatives. Most of these derivatives were able to be precipitated in crude form out of petroleum ether in sufficient purity for direct use as peptide building blocks. Subsequent incorporation of these derivatives into peptide models nicely illustrates their viability and applicability toward SPPS.


2012 ◽  
Vol 66 (8) ◽  
Author(s):  
Li-Xin Zhang ◽  
Yi-Xin Sun ◽  
Hong-Fang Jiu ◽  
Yue-Hua Fu ◽  
Yuan-Zhong Wang ◽  
...  

AbstractThis work presents a sol-gel carbon sphere template-assisted method of hollow Eu2O3 microspheres preparation. X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), as well as photoluminescence (PL) were used to characterise the products. The formation of hollow structure Eu2O3 microspheres can be assigned to a sol-gel carbon template. Furthermore, this work may confirm that the precursor sol-gel can be loaded onto the inner as well as the outer surface of carbon templates similarly as ions and nanocrystals. The presented method can afford a simple and efficient technique to obtain a series of hollow structure inorganic materials with high productivity.


2020 ◽  
Vol 18 (28) ◽  
pp. 5400-5405 ◽  
Author(s):  
Stefan Roesner ◽  
Jonathan D. Beadle ◽  
Leo K. B. Tam ◽  
Ina Wilkening ◽  
Guy J. Clarkson ◽  
...  

The synthesis and use of oxetane modified dipeptide building blocks in solution and solid-phase peptide synthesis (SPPS) is reported.


2011 ◽  
Vol 233-235 ◽  
pp. 2640-2643 ◽  
Author(s):  
Fu Sheng Song

Using tetraethoxysilane, aluminum nitrate and aluminum fluoride as raw materials, the precursor of mullite was prepared by sol-gel process. When the precursor sintered at 1200°C, mullite ceramic was obtained. Differential thermal analysis, X-ray powder diffraction and scanning electron microscope were used to characterize the dried mullite gel and ceramic blocks. The results suggest mullite is synthesized by solid-phase reaction mechanism. X-ray powder diffraction indicates mullite is the main crystals phase in the ceramic specimen. SEM micrograph shows the mullite grains in the shape of short rod with length of 20 um when sintered at 1200 °C for 2 h and the grains grown up to acicular with length of more than 50 um when the treating time under 1200 °C achieved to 4 h.


2020 ◽  
Author(s):  
Thissa N. Siriwardena ◽  
Bee-Ha Gan ◽  
Thilo Köhler ◽  
Christian van Delden ◽  
Sacha Javor ◽  
...  

<p>Solid-phase peptide synthesis (SPPS) is usually performed with optically pure building blocks to prepare peptides as single enantiomers. Herein we report that SPPS using racemic amino acids provides stereorandomized (<i>sr</i>) peptides, containing up to billions of different stereoisomers,<a> </a>as well-defined single HPLC peak, single mass products with high yield, which can be used to investigate peptide bioactivity. To exemplify our method, we show that stereorandomization abolishes the membrane disruptive effect of α-helical amphiphilic antimicrobial peptides but preserves their antibiofilm effect, implying different mechanisms involving folded versus disordered conformations. For antimicrobial peptide dendrimers by contrast, stereorandomization preserves antibacterial, membrane disruptive and anti-biofilm effects but reduces hemolysis and cytotoxicity, thereby increasing their therapeutic index. Finally, we identify partially stereorandomized analogs of the last resort cyclic peptide antibiotic polymyxin B with preserved antibacterial activity but lacking membrane disruptive and lipopolysaccharide neutralizing activity, pointing to the existence of additional targets.</p>


Author(s):  
Irshad A. Wani

The important aspect of nanotechnology is the remarkable size dependant physico-chemical properties of nanomaterials that have led to the development of synthesis protocols for synthesizing nanomaterials over a range of sizes, shapes, and chemical compositions. This chapter describes the various aspects of nanotechnology: its dimensions and manipulation of matter with primary focus on inorganic materials. Detailed accounts of various methods lying within top-down and bottom-up synthesis approaches are discussed, like Chemical Vapour Condensation (CVC), arc discharge, hydrogen plasma-metal reaction, and laser pyrolysis in the vapour phase, microemulsion, hydrothermal, sol-gel, sonochemical taking place in the liquid phase, and ball milling carried out in the solid phase. The chapter also presents a brief account of the various characterization techniques used for the identification of the nanomaterials: X-ray diffraction, UV-visible spectroscopy, and electron microscopy (e.g. Transmission Electron Microscopy [TEM], Scanning Electron Microscopy [SEM], Atomic Force Microscopy [AFM]).


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 672
Author(s):  
Christian Scherdel ◽  
Eddi Miller ◽  
Gudrun Reichenauer ◽  
Jan Schmitt

The requirements for new materials are increasing with each new application, which, in most cases, means an enhancement in the complexity of the development process. Nanoporous sol-gel-based materials, especially aerogels, are promising candidates for thermal superinsulation, electrodes for energy conversion and storage or high-end adsorbers. Their synthesis and processing route is complex, and the relationship between the material/processing parameters and the resulting structural and physical properties is not straightforward. Using small-angle X-ray scattering (SAXS) allows for fast structural characterization of both the gel and the resulting aerogel; combining these results with the respective physical properties of the aerogels and using these data as inputs for machine learning (ML) algorithms provide an approach to predict physical properties on the basis of a structural dataset. This data-driven strategy may be a feasible approach to speed up the development process. Thus, the study aimed to provide a proof of concept of ML-based model derivation from material, process and SAXS data to predict physical properties such as the solid-phase thermal conductivity (λs) of silica aerogels from a structural dataset. Here, we used different data subsets as predictors according to different states of synthesis (wet and dry) to evaluate the model performance.


2006 ◽  
Vol 960 ◽  
Author(s):  
Lixin Fan ◽  
David Paterson ◽  
Ian McNulty ◽  
M. M. J. Treacy ◽  
Dushyant Kumar ◽  
...  

ABSTRACTThe control of formation and ordering of self assembled nanostructures, with medium- to long-range order, is a challenge that limits advances in many fields of nanotechnology. We have developed a technique, which we call fluctuation x-ray microscopy, that offers quantitative insight into medium-range correlations in disordered materials at nanometer- and larger-length scales. We examined the influence of sol-gel process variables on medium range order in PI-b-PEO/ aluminosilicate bulk using this technique. The nano-structuring of inorganic materials was directed by polymer self-assembly. The medium range correlation between the nanostructures in two hybrids was quantitatively examined and compared.


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