DYNAMICS OF LEUCINE-RICH REPEAT PROTEINS

2007 ◽  
Vol 02 (03n04) ◽  
pp. 207-219 ◽  
Author(s):  
ANSUMAN LAHIRI ◽  
SOUMALEE BASU
Keyword(s):  
Mechanical Properties ◽  
Ligand Binding ◽  
Dispersion Curve ◽  
Elastic Strip ◽  
Leucine Rich Repeat ◽  
Ribonuclease Inhibitor ◽  
Repeat Number ◽  
Elastic Network ◽  
Repeat Proteins ◽  
Out Of Plane

We have studied the collective dynamics of leucine-rich repeat (LRR) proteins using an elastic network approximation. The slowest mode of the porcine ribonuclease inhibitor (pRI) protein could be visualized as bending fluctuations of a curved elastic strip leading to a planar opening–closing motion of the horseshoe which largely corresponded to the deformation of the protein on ligand binding. The second slowest mode however exhibited a significant out of plane splaying. The distribution of the lowest eigenvalues of different LRR proteins as a function of their repeat number was found to be close to the dispersion curve obtained from pRI whereas that of the leucine-rich variant (LRV) protein showed considerable deviation. The differing mechanical properties of these structurally similar solenoid proteins may have relevance to their function.

scholarly journals Mechanical Properties of Graphene Oxide Coupled by Multi-Physical Field: Grain Boundaries and Functional Groups

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Xu Xu ◽  
Zeping Zhang ◽  
Wenjuan Yao
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Grain Boundaries ◽  
Functional Groups ◽  
Oxygen Content ◽  
Tensile Fracture ◽  
Hydroxyl Groups ◽  
Molecular Configuration ◽  
Spatial Design ◽  
Out Of Plane

Graphene and graphene oxide (GO) usually have grain boundaries (GBs) in the process of synthesis and preparation. Here, we “attach” GBs into GO, a new molecular configuration i.e., polycrystalline graphene oxide (PGO) is proposed. This paper aims to provide an insight into the stability and mechanical properties of PGO by using the molecular dynamics method. For this purpose, the “bottom-up” multi-structure-spatial design performance of PGO and the physical mechanism associated with the spatial structure in mixed dimensions (combination of sp2 and sp3) were studied. Also, the effect of defect coupling (GBs and functional groups) on the mechanical properties was revealed. Our results demonstrate that the existence of the GBs reduces the mechanical properties of PGO and show an “induction” role during the tensile fracture process. The presence of functional groups converts in-plane sp2 carbon atoms into out-of-plane sp3 hybrid carbons, causing uneven stress distribution. Moreover, the mechanical characteristics of PGO are very sensitive to the oxygen content of functional groups, which decrease with the increase of oxygen content. The weakening degree of epoxy groups is slightly greater than that of hydroxyl groups. Finally, we find that the mechanical properties of PGO will fall to the lowest values due to the defect coupling amplification mechanism when the functional groups are distributed at GBs.

Designed leucine‐rich repeat proteins bind two muramyl dipeptide ligands

2021 ◽  
Author(s):  
Christina S. Kim ◽  
Anne M. Brown ◽  
Tijana Z. Grove ◽  
Felicia A. Etzkorn
Keyword(s):  
Muramyl Dipeptide ◽  
Leucine Rich Repeat ◽  
Repeat Proteins

Molecular cloning of novel leucine-rich repeat proteins and their expression in the developing mouse nervous system

1996 ◽  
Vol 35 (1-2) ◽  
pp. 31-40 ◽  
Author(s):  
Akihiko Taguchi ◽  
Akio Wanaka ◽  
Tetsuji Mori ◽  
Kazumasa Matsumoto ◽  
Yuji Imai ◽  
...  
Keyword(s):  
Nervous System ◽  
Molecular Cloning ◽  
Leucine Rich Repeat ◽  
Repeat Proteins

scholarly journals 1R0915 Geometrical analysis of leucine-rich repeat proteins

2002 ◽  
Vol 42 (supplement2) ◽  
pp. S93
Author(s):  
P Enhkbayar ◽  
M. Oosaki ◽  
Masakatsu M. ◽  
N. Matsushima
Keyword(s):  
Leucine Rich Repeat ◽  
Geometrical Analysis ◽  
Repeat Proteins

scholarly journals Structure optimization of woven fabric composites for improvement of mechanical properties using a micromechanics model of woven fabric composites and a genetic algorithm

2021 ◽  
Vol 30 ◽  
pp. 263498332110061
Author(s):  
Gunyong Hwang ◽  
Dong Hyun Kim ◽  
Myungsoo Kim
Keyword(s):  
Mechanical Properties ◽  
Genetic Algorithm ◽  
Elastic Modulus ◽  
Fiber Composite ◽  
Woven Fabric ◽  
Cross Sectional ◽  
Micromechanics Model ◽  
Woven Fabric Composites ◽  
Fabric Composites ◽  
Out Of Plane

This research aims to optimize the mechanical properties of woven fabric composites, especially the elastic modulus. A micromechanics model of woven fabric composites was used to obtain the mechanical properties of the fiber composite, and a genetic algorithm (GA) was employed for the optimization tool. The structure of the fabric fiber was expressed using the width, thickness, and wave pattern of the fiber strands in the woven fabric composites. In the GA, the chromosome string consisted of the thickness and width of the fill and warp strands, and the objective function was determined to maximize the elastic modulus of the composite. Numerical analysis showed that the longitudinal mechanical properties of the strands contributed significantly to the overall elastic modulus of the composites because the longitudinal property was notably larger than the transverse property. Therefore, to improve the in-plane elastic modulus, the resulting geometry of the composites possessed large volumes of related strands with large cross-sectional areas and small strand waviness. However, the numerical results of the out-of-plane elastic modulus generated large strand waviness, which contributed to the fiber alignment in the out-of-plane direction. The findings of this research are expected to be an excellent resource for the structural design of woven fabric composites.

scholarly journals Enhancement of out-of-plane mechanical properties of carbon fiber reinforced epoxy resin composite by incorporating the multi-walled carbon nanotubes

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Seyed Ali Mirsalehi ◽  
Amir Ali Youzbashi ◽  
Amjad Sazgar
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Test ◽  
Epoxy Resin ◽  
Laminate Composite ◽  
Filament Winding ◽  
Hybrid Nanocomposites ◽  
Out Of Plane ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractIn this study, epoxy hybrid nanocomposites reinforced by carbon fibers (CFs) were fabricated by a filament winding. To improve out-of-plane (transverse) mechanical properties, 0.5 and 1.0 Wt.% multi-walled carbon nanotubes (MWCNTs) were embedded into epoxy/CF composites. The MWCNTs were well dispersed into the epoxy resin without using any additives. The transverse mechanical properties of epoxy/MWCNT/CF hybrid nanocomposites were evaluated by the tensile test in the vertical direction to the CFs (90º tensile) and flexural tests. The fracture surfaces of composites were studied by scanning electron microscopy (SEM). The SEM observations showed that the bridging of the MWCNTs is one of the mechanisms of transverse mechanical properties enhancement in the epoxy/MWCNT/CF composites. The results of the 90º tensile test proved that the tensile strength and elongation at break of nanocomposite with 1.0 Wt.% MWCNTs improved up to 53% and 50% in comparison with epoxy/CF laminate composite, respectively. Furthermore, the flexural strength, secant modulus, and elongation of epoxy/1.0 Wt.% MWCNT/CF hybrid nanocomposite increased 15%, 7%, and 9% compared to epoxy/CF laminate composite, respectively.

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