Search results for " infrared spectroscopy"
showing 10 items of 438 documents
Assessment of temperature effects on beta-aggregation of native and glycated albumin by FTIR spectroscopy and PAGE: relations between structural chan…
2007
Abstract Structural modifications of bovine serum albumin (BSA) induced by heating, and the involvement of glycation of albumin in such processing were studied by using Fourier transform infrared spectroscopy (FTIR) and polyacrylamide gel electrophoresis (PAGE). For native BSA, heating treatments gave rise to β structures which were amplified to the detriment of α-helix form, and which were associated with increased aggregation. A very high correlation was obtained between FTIR Amide I band evolution and aggregation rate parameters, showing the contribution of β-form in aggregates formation. We further assessed the effect of glycation on protein sensibility to heating treatments. A reductio…
Relevance of Interactions between Starch-based Coatings and Plum Fruit Surfaces: A Physical-Chemical Analysis
2019
In order to extend the shelf life of the fruit, improve appearance, and to keep all nutrition properties of the plum from diminishing, edible coatings comprised of wheat starch and wheat starch&ndash
Keggin heteropolyacid supported on TiO2 used in gas-solid (photo)catalytic propene hydration and in liquid-solid photocatalytic glycerol dehydration
2017
Abstract (Photo)catalytic propene hydration to 2-propanol and glycerol dehydration to acrolein were carried out by using Keggin heteropolyacids (HPAs) supported on TiO 2 . Binary materials have been prepared by impregnation of H 3 PW 12 O 40 , H 3 PMo 12 O 40 and H 4 SiW 12 O 40 , on TiO 2 Evonik P25. Moreover, a binary material consisting of H 4 SiW 12 O 40 and TiO 2 was prepared via a hydrothermal treatment and tested for the same reactions. All the materials were characterized by X-ray diffraction (XRD), scanning electron microscopy observations (SEM) coupled with energy dispersive X-ray (EDX) measurements, diffuse reflectance spectroscopy (DRS), Raman spectroscopy and Fourier transform …
Interaction of metal ions with N-glycosylamines: isolation and characterization of the products of 4,6-O-benzylidene-N-(o-carboxyphenyl)-β-D-glucopyr…
2001
Metal-ion complexes of Li+, Na+, K+, Mg2+, Ca2+, Ba2+, Pb2+, Cd2+, Hg2+ with 4,6–O–benzylidene–N–(o–carboxyphenyl)–β–D–glucopyranosylamine were synthesized and isolated as solid products and characterized by analytical means as well as by spectral techniques, such as, 1H and 13C NMR, FTIR, absorption, FAB mass spectrometry, optical rotation and CD. While the alkali metal ions formed ML type of complexes, the other metal ions formed ML2 type complexes. Molecular weights of the complexes of Li+, Na+ and K+ were established based on the molecular-ion peaks in the FAB mass spectra. The saccharide portion remians in the β-anomeric form even after the complexation. The spectral data, as well as t…
Role of Solvent on Protein-Matrix Coupling in MbCO Embedded in Water-Saccharide Systems: A Fourier Transform Infrared Spectroscopy Study
2006
AbstractEmbedding protein in sugar systems of low water content enables one to investigate the protein dynamic-structure function in matrixes whose rigidity is modulated by varying the content of residual water. Accordingly, studying the dynamics and structure thermal evolution of a protein in sugar systems of different hydration constitutes a tool for disentangling solvent rigidity from temperature effects. Furthermore, studies performed using different sugars may give information on how the detailed composition of the surrounding solvent affects the internal protein dynamics and structural evolution. In this work, we compare Fourier transform infrared spectroscopy measurements (300–20K) o…
Thermal evolution of the CO stretching band in carboxy-myoglobin in the light of neutron scattering and molecular dynamics simulations
2008
Abstract As it is well known, the thermal behaviour of the CO stretching band in MbCO reflects the interconversion among protein’s taxonomic and lower tier substates. We compare here FTIR data on the thermal behaviour of the CO stretching band in MbCO embedded in non-liquid, water–trehalose matrixes, and neutron scattering data on dry and hydrated proteins and nucleic acids. The comparison, also in the light of simulative data, gives relevant information on the relationship between the mean square displacements of hydrogen atoms and the heme pocket thermal rearrangements in MbCO, as experienced by the bound CO, in the temperature region 100–200 K, and at higher temperature when large scale …
Nouvelles perspectives concernant la structure et la fonction du domaine carboxyl terminal de Hfq
2015
Accumulating evidence indicates that RNA metabolism components assemble into supramolecular cellular structures to mediate functional compartmentalization within the cytoplasmic membrane of the bacterial cell. This cellular compartmentalization could play important roles in the processes of RNA degradation and maturation. These components include Hfq, the RNA chaperone protein, which is involved in the post-transcriptional control of protein synthesis mainly by the virtue of its interactions with several small regulatory ncRNAs (sRNA). The Escherichia coli Hfq is structurally organized into two domains. An N-terminal domain that folds as strongly bent β-sheets within individual protomers to…
Advanced Spectroscopic Detectors for Identification and Quantification
2013
The coupling of vibration spectroscopic detectors to liquid chromatography (LC) is an interesting analytical tool that allows combining high resolution from LC with molecular specific information accessible by infrared (IR) and Raman spectrometry. This chapter describes the basics of IR and Raman spectroscopy with a special emphasis on the advantages and pitfalls of these detection techniques in LC. Two fundamentally different coupling approaches, namely, off-line hyphenation involving the physical elimination of the mobile phase and on-line hyphenation through the use of flow cells, are discussed in detail, describing the most important interfaces and diverse practical applications. Strate…
Carbonyl metallo immuno assay: a new application for Fourier transform infrared spectroscopy
2000
Abstract We describe here the development of a new, non-isotopic immunological assay termed CMIA (carbonyl metallo immunoassay) that uses metal carbonyl complexes as tracers and Fourier transform infrared spectroscopy (FT-IR) as the detection method. This assay is based on the particular spectral features of these complexes, which show very strong absorption bands in the 1800–2200 cm −1 spectral range where proteins and organic molecules do not absorb. In Section 1 , the optimisation of the quantitative detection of these tracers is detailed. In Section 2 , the implementation of mono-CMIA is described, including the CMIA assays of three antiepileptic drugs (carbamazepine, phenobarbital, phe…
Study of the influence of dynamics variables on the growth of silica nanoparticles
2017
In this work 29Si nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared spectroscopy (FTIR) were used to analyze in situ the formation process of silica nanoparticles from ba...