scholarly journals Effect of Single Amino Acid Substitutions by Asn and Gln on Aggregation Properties of Bence-Jones Protein BIF

2019 ◽  
Vol 20 (20) ◽  
pp. 5197
Author(s):  
Maria Timchenko ◽  
Azat Abdullatypov ◽  
Hiroshi Kihara ◽  
Alexander Timchenko
Keyword(s):  
Single Amino Acid ◽  
Renal Amyloidosis ◽  
Renal Tubules ◽  
Bence Jones Protein ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Amyloid Deposits ◽  
Α Helix ◽  
Bence Jones Proteins

The nature of renal amyloidosis involving Bence-Jones proteins in multiple myeloma is still unclear. The development of amyloidosis in neurodegenerative diseases is often associated with a high content of asparagine and glutamine residues in proteins forming amyloid deposits. To estimate the influence of Asn and Gln residues on the aggregation of Bence-Jones protein BIF, we obtained recombinant BIF and its mutants with the substitution of Tyr187→Asn (Y187N) in α-helix of CL domain, Lys170→Asn (K170N) and Ser157→Gln (S157Q) in CL domain loops, Arg109→Asn in VL-CL linker (R109N) and Asp29→Gln in VL domain loop (D29Q). The morphology of protein aggregates was studied at pH corresponding to the conditions in bloodstream (pH 7.2), distal (pH 6.5) and proximal renal tubules (pH 4.5) by atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS). The Lys170→Asn replacement almost completely inhibits amyloidogenic activity. The Y187N forms fibril-like aggregates at all pH values. The Arg109→Asn replacement resulted in formation of fibril-like structures at pH 7.2 and 6.5 while the substitutions by Gln provoked formation of those structures only at pH 7.2. Therefore, the amyloidogenic properties are highly dependent on the location of Asn or Gln.

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.

Coupling In-Situ Techniques to Analyze Zinc Deposition and Dissolution for Energy Storage Applications

2013 ◽  
Vol 1491 ◽  
Author(s):  
Jayme Keist ◽  
Christine Orme ◽  
Frances Ross ◽  
Dan Steingart ◽  
Paul Wright ◽  
...  
Keyword(s):  
Liquid Electrolyte ◽  
Scattering Data ◽  
Zinc Deposition ◽  
Ionic Liquid Electrolyte ◽  
Force Microscopy ◽  
In Situ Techniques ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Afm Analysis

ABSTRACTThis investigation describes preliminary results of in-situ analysis of zinc deposition within an ionic liquid electrolyte utilizing electrochemical atomic force microscopy (EC AFM). From the AFM analysis, the morphology of the zinc deposition was analyzed by quantifying the surface roughness using height-height correlation functions. These results will be used to analyze the scattering data obtained from zinc deposition analysis utilizing an electrochemical ultra-small angle x-ray scattering (EC USAXS). The goal of this research is to link the early nucleation and growth behavior to the formation of detrimental morphologies.

scholarly journals Study on the morphology and thermomechanical properties of poly(urethane-siloxane) networks based on hyperbranched polyester

2013 ◽  
Vol 67 (6) ◽  
pp. 871-879
Author(s):  
Marija Pergal ◽  
Jasna Dzunuzovic ◽  
Milena Spírková ◽  
Rafal Poręba ◽  
Milos Steinhart ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Microphase Separation ◽  
Soft Segment ◽  
Hydrophobic Surface ◽  
Crosslinking Density ◽  
Thermomechanical Properties ◽  
Hyperbranched Polyester ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force

Two series of polyurethane films based on hyperbranched polyester of the second pseudogeneration (Boltorn?), 4,4'-methylenediphenyl diisocyanate and two different siloxane prepolymers, ?,?-dihydroxy-(ethylene oxide-poly(dimethylsiloxane)-ethylene oxide) (EO-PDMS-EO) and ?,?-dihydroxypropyl-poly(dimethylsiloxane) (HP-PDMS), were prepared by two-step polymerization in solution. The influence of the type and content of soft segment on the morphology, thermomechanical and surface properties of the synthesized polyurethanes was studied by atomic force microscopy (AFM), small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA) and water absorption measurements. It was found that these techniques confirmed existence of microphase separated morphology. Synthesized polyurethanes exhibited two glass transition temperatures and one second relaxation process. The results showed that polyurethanes based on HP-PDMS had higher surface roughness, better microphase separation and waterproof performances. Samples synthesized with lower PDMS content had less hydrophobic surface, but higher crosslinking density and better thermomechanical properties. (Projekat Ministarstva nauke Republike Srbije, br. 172062]

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.

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.

The surface roughness investigation by the atomic force microscopy, x-ray scattering, and light scattering

2006 ◽  
Author(s):  
M. L. Zanaveskin ◽  
Yu. V. Grishchenko ◽  
A. L. Tolstikhina ◽  
V. E. Asadchikov ◽  
B. S. Roshchin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Light Scattering ◽  
X Ray ◽  
Force Microscopy ◽  
X Ray Scattering ◽  
Atomic Force ◽  
Ray Scattering
Sign in / Sign up

Export Citation Format

Share Document