scholarly journals Fractal dimension of an intrinsically disordered protein: Small-angle X-ray scattering and computational study of the bacteriophage λ N protein

2011 ◽  
Vol 20 (12) ◽  
pp. 1955-1970 ◽  
Author(s):  
Daniel Johansen ◽  
Jill Trewhella ◽  
David P. Goldenberg
Keyword(s):  
Fractal Dimension ◽  
Small Angle ◽  
Computational Study ◽  
Intrinsically Disordered Protein ◽  
Bacteriophage Λ ◽  
X Ray ◽  
N Protein ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
X Ray Scattering

scholarly journals Structural characterization of the N-terminal part of the MERS-CoV nucleocapsid by X-ray diffraction and small-angle X-ray scattering

2016 ◽  
Vol 72 (2) ◽  
pp. 192-202 ◽  
Author(s):  
Nicolas Papageorgiou ◽  
Julie Lichière ◽  
Amal Baklouti ◽  
François Ferron ◽  
Marion Sévajol ◽  
...  
Keyword(s):  
Structural Model ◽  
Structural Features ◽  
Terminal Region ◽  
X Ray Diffraction ◽  
Terminal Part ◽  
Multifunctional Protein ◽  
X Ray ◽  
N Protein ◽  
Intrinsically Disordered ◽  
X Ray Scattering

The N protein of coronaviruses is a multifunctional protein that is organized into several domains. The N-terminal part is composed of an intrinsically disordered region (IDR) followed by a structured domain called the N-terminal domain (NTD). In this study, the structure determination of the N-terminal region of the MERS-CoV N proteinviaX-ray diffraction measurements is reported at a resolution of 2.4 Å. Since the first 30 amino acids were not resolved by X-ray diffraction, the structural study was completed by a SAXS experiment to propose a structural model including the IDR. This model presents the N-terminal region of the MERS-CoV as a monomer that displays structural features in common with other coronavirus NTDs.

ULTRA SMALL-ANGLE X-RAY SCATTERING STUDY OF FLOCCULATION IN SILICA-FILLED RUBBER

2014 ◽  
Vol 87 (2) ◽  
pp. 348-359 ◽  
Author(s):  
Satoshi Mihara ◽  
Rabin N. Datta ◽  
Wilma K. Dierkes ◽  
Jacques W. M. Noordermeer ◽  
Naoya Amino ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Small Angle ◽  
Radius Of Gyration ◽  
X Ray ◽  
X Ray Scattering ◽  
Mass Fractal ◽  
Mass Fractal Dimension ◽  
Lower Mobility ◽  
Low Mass ◽  
Ray Scattering

ABSTRACT The flocculation of silica during vulcanization is monitored using the ultra small-angle X-ray scattering technique for two different types of silica: a highly dispersible silica (HD) and a conventional silica (CV), mixed into a blend of S-SBR and BR rubbers. The cutoff length of the silica aggregate Rss and the mass fractal dimension Dm, which indicate the degree of flocculation of aggregates, are estimated according to the modified unified equation. The aggregate radius Ra is estimated to be related to the lower cutoff length Rss, indicating the radius of gyration of the mass-fractal structure. For both silicas, Ra increases during vulcanization. For the CV silica, an increase of Dm is observed, whereas no significant increase of Dm can be seen for the HD silica. The Ra of CV is relatively high compared with that of HD. On the other hand, the CV silica shows a relatively lower Dm compared with that of HD. These results indicate that CV has a larger size of aggregates and lower degree of agglomeration of its aggregates. The presence of di(tri-ethoxy-silyl-propyl)tetrasulfide (TESPT) as coupling agent between the silica and rubber decreases the aggregate radius of silica. However, in the absence of TESPT, a low mass-fractal dimension, which means a low degree of agglomeration of aggregates, is observed. This results from a lower mobility of silica aggregates, depending on the size of the aggregates. The silica loading also has an influence on the flocculation process. The aggregate radius increases as the silica loading is increased. At the same time, a higher mass-fractal dimension, and therefore also a higher degree of agglomeration, can be seen at higher silica loading.

scholarly journals X-ray structure of the PHF core C-terminus: Insight into the folding of the intrinsically disordered protein tau in Alzheimer's disease

FEBS Letters ◽  
2007 ◽  
Vol 581 (30) ◽  
pp. 5872-5878 ◽  
Author(s):  
Jozef Sevcik ◽  
Rostislav Skrabana ◽  
Radovan Dvorsky ◽  
Natalia Csokova ◽  
Khalid Iqbal ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Intrinsically Disordered Protein ◽  
X Ray ◽  
Protein Tau ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
C Terminus ◽  
Insight Into

Small Angle X-ray Scattering Test of Hami Coal Sample Nanostructure Parameters with Gas Adsorbed Under Different Pressures

2021 ◽  
Vol 21 (1) ◽  
pp. 538-546
Author(s):  
Baisheng Nie ◽  
Kedi Wang ◽  
Yu Fan ◽  
Junsheng Zhao ◽  
Letong Zhang ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Small Angle ◽  
Coalbed Methane ◽  
Gas Adsorption ◽  
Gas Diffusion ◽  
X Ray ◽  
X Ray Scattering ◽  
Surface Dimension ◽  
Nanopore Structure ◽  
Ray Scattering

The complexity and multiscale structure of coal pores significantly influence the gas diffusion and seepage characteristics of coal. To apply small angle X-ray scattering (SAXS) to study the coal pore structure parameters within the scale of 1–100 nm in the methane adsorption process, the X-ray window was optimized and a gas adsorption chamber was designed to interface with the small angle X-ray scattering platform. The fractal dimension and porosity of Hami coal samples under different methane pressures were studied using the small angle X-ray scattering platform and adsorption chamber. The surface and nanopore fractal information of the nanopores in coal were distinguished. The variation trends of the pores and surface fractal dimension with time under the same methane pressure were compared. The results indicate that the surface dimension changes from 2.56 to 2.75, and the extremum point may indicate that the primary nanopore structure is crushed by the adsorbed gas after approximately 15 minutes. This work clarifies that the fractal dimension can characterize the changes in nanopores in the process of gas adsorption by using SAXS. According to the fractal characteristics, the adsorption of gas in coal nanopores is summarized as four steps: expansion from adsorbance, deformation, crushing and recombination. The minimum porosity is 0.95% and the extreme value point is 1.47%. This work also shows that decrease in surface energy affect the porosity changes in nano-size pores. This work is of some significance to coalbed methane permeability improvement and gas extraction.

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