scholarly journals A Study of the Interaction, Morphology, and Structure in Trypsin-Epigallocatechin-3-Gallate Complexes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4567
Author(s):  
Jiayin Liu ◽  
Hossein Ghanizadeh ◽  
Xinmao Li ◽  
Zhengyuan Han ◽  
Youwen Qiu ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Digestive Enzymes ◽  
Amino Acid Residues ◽  
Cd Spectra ◽  
X Ray ◽  
Food Industries ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Fluorescent Amino Acid ◽  
Saxs Analysis

Understanding the interaction between proteins and polyphenols is of significance to food industries. The aim of this research was to investigate the mode of aggregation for trypsin-EGCG (Epigallocatechin-3-gallate) complexes. For this, the complex was characterized by fluorescence spectroscopy, circular dichroism (CD) spectra, small-angel X-ray scattering (SAXS), and atomic force microscope (AFM) techniques. The results showed that the fluorescence intensity of trypsin-EGCG complexes decreased with increasing the concentration of EGCG, indicating that the interaction between trypsin and EGCG resulted in changes in the microenvironment around fluorescent amino acid residues. The results of CD analysis showed conformational changes in trypsin after binding with EGCG. The results from SAXS analysis showed that the addition of EGCG results in the formation of aggregates of trypsin-EGCG complexes, and increasing the concentration of EGCG resulted in larger aggregates. AFM images showed that the trypsin-EGCG complex formed aggregates of irregular ellipsoidal shapes with the size of about 200 × 400 × 200 nm, with EGCG interconnecting the trypsin particles. Overall, according to these results, it was concluded that the large aggregates of trypsin-EGCG complexes are formed from several small aggregates that are interconnected. The results of this study shed some light on the interaction between digestive enzymes and EGCG.

scholarly journals Pilot study on the effects of preservatives on corneal collagen parameters measured by small angle X-ray scattering analysis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Susyn Joan Kelly ◽  
Lizette duPlessis ◽  
John Soley ◽  
Frazer Noble ◽  
Hannah Carolyn Wells ◽  
...  
Keyword(s):  
Small Angle ◽  
Collagen Fibril ◽  
Diameter Distribution ◽  
X Ray ◽  
X Ray Scattering ◽  
Saxs Analysis ◽  
Triton X ◽  
Fibril Diameter ◽  
Corneal Collagen ◽  
Ray Scattering

Abstract Objective Small angle X-ray scattering (SAXS) analysis is a sensitive way of determining the ultrastructure of collagen in tissues. Little is known about how parameters measured by SAXS are affected by preservatives commonly used to prevent autolysis. We determined the effects of formalin, glutaraldehyde, Triton X and saline on measurements of fibril diameter, fibril diameter distribution, and D-spacing of corneal collagen using SAXS analysis. Results Compared to sections of sheep and cats’ corneas stored frozen as controls, those preserved in 5% glutaraldehyde and 10% formalin had significantly larger mean collagen fibril diameters, increased fibril diameter distribution and decreased D-spacing. Sections of corneas preserved in Triton X had significantly increased collagen fibril diameters and decreased fibril diameter distribution. Those preserved in 0.9% saline had significantly increased mean collagen fibril diameters and decreased diameter distributions. Subjectively, the corneas preserved in 5% glutaraldehyde and 10% formalin maintained their transparency but those in Triton X and 0.9% saline became opaque. Subjective morphological assessment of transmission electron microscope images of corneas supported the SAXS data. Workers using SAXS analysis to characterize collagen should be alerted to changes that can be introduced by common preservatives in which their samples may have been stored.

In situ X-ray Scattering Study of the Formation of Au Nano Crystals During Thermal Annealing

2007 ◽  
Vol 1027 ◽  
Author(s):  
Do Young Noh ◽  
Ki-Hyun Ryu ◽  
Hyon Chol Kang
Keyword(s):  
Thermal Annealing ◽  
Bragg Reflection ◽  
Ex Situ ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Au Thin Films ◽  
Ray Scattering

AbstractThe transformation of Au thin films grown on sapphire (0001) substrates into nano crystals during thermal annealing was investigated by in situ synchrotron x-ray scattering and ex situ atomic force microscopy (AFM). By monitoring the Au(111) Bragg reflection and the low Q reflectivity and comparing them with ex situ AFM images, we found that polygonal-shape holes were nucleated and grow initially. As the holes grow larger and contact each other, their boundary turns into Au nano crystals. The Au nano crystals have a well-defined (111) flat top surface and facets in the in-plane direction.

scholarly journals Exploring the in meso crystallization mechanism by characterizing the lipid mesophase microenvironment during the growth of single transmembrane α-helical peptide crystals

2016 ◽  
Vol 374 (2072) ◽  
pp. 20150125 ◽  
Author(s):  
Leonie van 't Hag ◽  
Konstantin Knoblich ◽  
Shane A. Seabrook ◽  
Nigel M. Kirby ◽  
Stephen T. Mudie ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Self Assembly ◽  
Lamellar Phase ◽  
Cubic Phase ◽  
Supporting Evidence ◽  
X Ray ◽  
X Ray Scattering ◽  
Standard Procedures ◽  
Helical Peptide ◽  
Saxs Analysis

The proposed mechanism for in meso crystallization of transmembrane proteins suggests that a protein or peptide is initially uniformly dispersed in the lipid self-assembly cubic phase but that crystals grow from a local lamellar phase, which acts as a conduit between the crystal and the bulk cubic phase. However, there is very limited experimental evidence for this theory. We have developed protocols to investigate the lipid mesophase microenvironment during crystal growth using standard procedures readily available in crystallography laboratories. This technique was used to characterize the microenvironment during crystal growth of the DAP12-TM peptide using synchrotron small angle X-ray scattering (SAXS) with a micro-sized X-ray beam. Crystal growth was found to occur from the gyroid cubic mesophase. For one in four crystals, a highly oriented local lamellar phase was observed, providing supporting evidence for the proposed mechanism for in meso crystallization. A new observation of this study was that we can differentiate diffraction peaks from crystals grown in meso , from peaks originating from the surrounding lipid matrix, potentially opening up the possibility of high-throughput SAXS analysis of in meso grown crystals. This article is part of the themed issue ‘Soft interfacial materials: from fundamentals to formulation’.

scholarly journals REGALS: a general method to deconvolve X-ray scattering data from evolving mixtures

2020 ◽  
Author(s):  
Steve P. Meisburger ◽  
Da Xu ◽  
Nozomi Ando
Keyword(s):  
A Priori ◽  
Scattering Data ◽  
Biological Macromolecules ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Open Source Software Package ◽  
Saxs Analysis ◽  
Structural Methods ◽  
Ray Scattering

AbstractMixtures of biological macromolecules are inherently difficult to study using structural methods, as increasing complexity presents new challenges for data analysis. Recently, there has been growing interest in studying evolving mixtures using small-angle X-ray scattering (SAXS) in conjunction with time-resolved, high-throughput, or chromatography-coupled setups. Deconvolution and interpretation of the resulting datasets, however, are nontrivial when neither the scattering components nor the way in which they evolve are known a priori. To address this issue, we introduce the REGALS method (REGularized Alternating Least Squares), which incorporates simple expectations about the data as prior knowledge and utilizes parameterization and regularization to provide robust deconvolution solutions. The restraints used by REGALS are general properties such as smoothness of profiles and maximum dimensions of species, which makes it well-suited for exploring datasets with unknown species. Here we apply REGALS to analyze experimental data from four types of SAXS experiment: anion-exchange (AEX) coupled SAXS, ligand titration, time-resolved mixing, and time-resolved temperature jump. Based on its performance with these challenging datasets, we anticipate that REGALS will be a valuable addition to the SAXS analysis toolkit and enable new experiments. The software is implemented in both MATLAB and python and is available freely as an open-source software package.

Intrinsic roughness and interfaces of Cr/Be multilayers

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Roman Pleshkov ◽  
Nikolay Chkhalo ◽  
Vladimir Polkovnikov ◽  
Mikhail Svechnikov ◽  
Maria Zorina
Keyword(s):  
Atomic Force Microscopy ◽  
Optical Contrast ◽  
Multilayer Mirrors ◽  
X Ray ◽  
Force Microscopy ◽  
Layer Material ◽  
Multilayer Mirror ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Sharp Structure

The structures of Cr/Be multilayer mirror interfaces are investigated using X-ray reflectometry, diffuse X-ray scattering and atomic force microscopy. The combination of these methods makes it possible to separate the contributions of roughness and interlayer diffusion/intermixing for each sample. In the range of period thicknesses of 2.26–0.8 nm, it is found that the growth roughness of the Cr/Be multilayer mirrors does not depend on the period thickness and is ∼0.2 nm. The separation of roughness and diffuseness allows estimation of layer material intermixing and the resulting drop in the optical contrast, which is from 0.85 to 0.17 in comparison with an ideally sharp structure.

scholarly journals In Situ Synchrotron X-ray Study of the Mechanical Properties of Pure Mg Produced by Powder Metallurgy

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1198
Author(s):  
Li Li ◽  
Leyun Wang ◽  
Jie Wang ◽  
Huan Zhang ◽  
Qingchun Zhu ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Tensile Deformation ◽  
Line Broadening ◽  
X Ray ◽  
X Ray Scattering ◽  
Type Dislocation ◽  
Diffraction Patterns ◽  
Saxs Analysis ◽  
Ray Scattering

In this study, in situ synchrotron X-ray experiments with wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) detectors were performed on two pure magnesium materials produced by powder metallurgy. According to SAXS analysis, each of the two materials has a porosity of less than 0.5%. Line broadening analysis was performed on diffraction patterns collected by WAXS to analyze the dislocation evolution during material deformation. In both materials, <a>-type dislocation activities dominate the tensile deformation. The influence of grain size and texture on the different tensile behaviors of these two materials is also discussed.

Comparative study of the roughness of optical surfaces and thin films by use of x-ray scattering and atomic force microscopy

1999 ◽  
Vol 38 (4) ◽  
pp. 684 ◽  
Author(s):  
Victor E. Asadchikov ◽  
Angela Duparré ◽  
Stefan Jakobs ◽  
Albert Yu. Karabekov ◽  
Igor V. Kozhevnikov ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Comparative Study ◽  
X Ray ◽  
Force Microscopy ◽  
Optical Surfaces ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Ray Scattering

Microstructural Characterization of Polyanhydride Blends for Controlled Drug Delivery

2000 ◽  
Vol 662 ◽  
Author(s):  
Elizabeth E. Shen ◽  
Hsin-Lung Chen ◽  
Balaji Narasimhan
Keyword(s):  
Drug Delivery ◽  
Microstructural Characterization ◽  
Peak Shift ◽  
Crystalline Morphology ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Drug Delivery Devices

AbstractThis research examines the microstructure of polyanhydride blends for use in drug delivery devices. Atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) studies were performed on the homopolymers and blends of the polyanhydrides poly(1,6-carboxyphenoxy hexane) (CPH) and poly(sebacic anhydride) (SA). AFM of the CPH/SA blends 20:80, 50:50, and 80:20 showed distinct patterns indicating spinodal decomposition and phase separation on the micron-scale. Because it has been shown that incorporated drugs will thermodynamically partition into phase-separated domains depending on their hydrophobicity, polyanhydride blends will be able to encapsulate larger bioactive compounds including nucleotides, proteins, and vaccines. Preliminary SAXS studies of the CPH/SA blend systems provide information on the crystalline morphology of the polymer. A peak shift to a lower q from poly(SA) to the blends indicates that the poly(CPH) is incorporated into and causes swelling of the interlamellar amorphous regions of poly(SA).

When dendrimers are not better – rational design of nanolayers for high-performance organic electronic devices

Nanoscale ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 4463-4470 ◽  
Author(s):  
Maxim A. Shcherbina ◽  
Oleg V. Borshchev ◽  
Alexandra P. Pleshkova ◽  
Sergei A. Ponomarenko ◽  
Sergei N. Chvalun
Keyword(s):  
High Performance ◽  
Rational Design ◽  
Electronic Devices ◽  
Carbosilane Dendrimers ◽  
Scanning Calorimetry ◽  
Organic Electronic Devices ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force

Several generations of carbosilane dendrimers with quaterthiophene end groups were studied by X-ray scattering, differential scanning calorimetry, polarizing optical and atomic force microscopy and molecular modelling.

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