scholarly journals Predicting protein thermal stability changes upon point mutations using statistical potentials: Introducing HoTMuSiC

2016 ◽  
Author(s):  
Fabrizio Pucci ◽  
Raphaël Bourgeas ◽  
Marianne Rooman

The accurate prediction of the impact of an amino acid substitution on the thermal stability of a protein is a central issue in protein science, and is of key relevance for the rational optimization of various bioprocesses that use enzymes in unusual conditions. Here we present one of the first computational tools to predict the change in melting temperature ΔTmupon point mutations, given the protein structure and, when available, the melting temperature Tmof the wild-type protein. The key ingredients of our model structure are standard and temperature-dependent statistical potentials, which are combined with the help of an artificial neural network. The model structure was chosen on the basis of a detailed thermodynamic analysis of the system. The parameters of the model were identified on a set of more than 1,600 mutations with experimentally measured ΔTm. The performance of our method was tested using a strict 5-fold cross-validation procedure, and was found to be significantly superior to that of competing methods. We obtained a root mean square deviation between predicted and experimental ΔTmvalues of 4.2°C that reduces to 2.9°C when ten percent outliers are removed. A webserver-based tool is freely available for non-commercial use at soft.dezyme.com.

2013 ◽  
Author(s):  
Jr Morris ◽  
Shardo Robert W. ◽  
Higgins James ◽  
Cook Kim ◽  
Tanner Rhonda ◽  
...  

RSC Advances ◽  
2020 ◽  
Vol 10 (51) ◽  
pp. 30934-30943 ◽  
Author(s):  
Yongfeng Tong ◽  
Meryem Bouaziz ◽  
Hamid Oughaddou ◽  
Hanna Enriquez ◽  
Karine Chaouchi ◽  
...  

LEED, STM and XPS techniques were used to systematically study a temperature-dependent phase transition on a PtSe2 film grown on the surface of Pt(111) by a chemical deposition method.


Author(s):  
Q. Wu ◽  
Y. Lei ◽  
F. Yao ◽  
Y. Xu ◽  
K. Lian

Composites based on high density polyethylene (HDPE), pine flour, and organic clay were made by melt compounding and injection molding. The influence of clay on crystallization behavior, mechanical properties, water absorption, and thermal stability of HDPE/pine composites were investigated. The HDPE/pine composites containing exfoliated clay were made by a two-step melt compounding procedure with a maleated polyethylene (MAPE) as a compatibilizer. Adding 2% clay to a HDPE/pine composite without MAPE decreased the crystallization temperature (Tc) and rate, and the crystallinity level. When 2% MAPE was added, the Tc and crystallization rate increased, but the crystallinity level was lowered. The flexural strength and the tensile strength of HDPE/pine composites increased 19.6% and 24.2% respectively with addition of 1% clay but then decreased slightly as the clay content was increased to 3%. The tensile modulus and tensile elongation were increased 11.8% and 13% respectively with addition of 1% clay but the storage and loss moduli barely change as the clay content was increased to 3%. The impact strength was lowered 7.5% by adding 1% clay, but did not decrease further as more clay was added. The moisture content and thickness swelling of the HDPE/pine composites was reduced by the clay, but did not improve the thermal stability.


2012 ◽  
Vol 535-537 ◽  
pp. 154-160 ◽  
Author(s):  
Anizah Kalam ◽  
M.N. Berhan ◽  
Hanafi Ismail

Hybrid composites were prepared by incorporating oil palm fruit bunch (OPFB) fibre in the mixture of clay and polypropylene as secondary filler. OPFB and MAPP loadings were varied to investigate it effects on the performance. Tensile and impact tests were performed on the hybrid composites to evaluate their mechanical performances. Water absorption and thermal degradation tests were also conducted on the hybrid composites. Results indicated that the incorporation of OPFB in PP/PPnanoclay has decreased the thermal stability of hybrid composites. Tensile modulus of hybrid composites increased as the OPFB loading increases and further increased with the increasing of MAPP loading. Generally the tensile strength has decreased with the addition of OPFB, however slight increased was observed when the MAPP loading was increased. The impact strength has also increased with the increasing of OPFB for higher MAPP loading.


2017 ◽  
Vol 31 (07) ◽  
pp. 1741001
Author(s):  
Yanlin Jia ◽  
Siqi Li ◽  
Weihong Qi ◽  
Mingpu Wang ◽  
Zhou Li ◽  
...  

Molecular dynamics (MDs) simulations were used to explore the thermal stability of Au nanoparticles (NPs) with decahedral, cuboctahedral, icosahedral and Marks NPs. According to the calculated cohesive energy and melting temperature, the Marks NPs have a higher cohesive energy and melting temperature compared to these other shapes. The Lindemann index, radial distribution function, deformation parameters, mean square displacement and self-diffusivity have been used to characterize the structure variation during heating. This work may inspire researchers to prepare Marks NPs and apply them in different fields.


2016 ◽  
Vol 29 (10) ◽  
pp. 1199-1208 ◽  
Author(s):  
Dezhi Wang ◽  
Xin Wang ◽  
Lizhu Liu ◽  
Chunyan Qu ◽  
Changwei Liu ◽  
...  

Structural materials with excellent toughness, a wide processing window, outstanding mechanical performance, and high thermal stability are highly desired in engineering. This work reports a novel bismaleimide (BMI) resin system fabricated using bis[4-(4-maleimidephen-oxy)phenyl)]propane (BMPP), 1-(2-methyl-5-(2,5-dioxo-2H-pyrrol-1(5 H)-yl) phenyl)-1H-pyrrole-2,5-dione (BTM), and diallyl bisphenol A (DABPA) by a melt method. The behaviors of the BTM/BMPP/DABPA resin were modified by adding vinyl-terminated butadiene acrylonitrile (VTBN) in various amounts. The cured BTM/BMPP/DABPA/VTBN resin system exhibited all of the abovementioned desirable properties. Excellent performance was achieved by the post-cured BMI resin containing 6 phr of VTBN (VTBN-6). The glass transition temperature ( Tg) and the 5% weight loss temperature of VTBN-6 were 278°C and 408°C, respectively. Relative to VTBN-0 (BMI resin without VTBN), the impact strength of cured VTBN-6 (12.32 KJ/m2) improved by 45.6%, and the fracture toughness values, KIC and GIC, increased by 48.7% and 26%, respectively. Moreover, the prepolymer of VTBN-6 exhibited low viscosity over a wide temperature range (70–200°C) under dynamic conditions and for an extended time (70 min; 75% improvement over VTBN-0) in an isothermal test. These results confirm the wide processing window of VTBN-6. The high toughness of the VTBN-containing BMI resin was compatible with other excellent performances of the modified resin.


2014 ◽  
Vol 268 ◽  
pp. 315-325 ◽  
Author(s):  
Patrick Röder ◽  
Barbara Stiaszny ◽  
Jörg C. Ziegler ◽  
Nilüfer Baba ◽  
Paul Lagaly ◽  
...  

2016 ◽  
Vol 4 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Léa Chancelier ◽  
Olivier Boyron ◽  
Thibaut Gutel ◽  
Catherine Santini

This work highlights the factors tuning the thermal stability of imidazolium-based ionic liquids (IL) associated to bis(trifluoromethanesulfonyl)imide anion [NTf2]. The decomposition temperatures (Td) were evaluated by thermogravimetric analyses (TGA) with optimized parameters to obtain reproducible Td. The impact of the alkyl chain length and of the presence of functional groups and unsaturations on Td were evaluated. The thermal behaviour was governed by Van der Waals interactions between alkyl chains, and by inter and intra coulombic interactions such as hydrogen bonds.


2016 ◽  
Author(s):  
Fabrizio Pucci ◽  
Marianne Rooman

AbstractDespite the intense efforts of the last decades to understand the thermal stability of proteins, the mechanisms responsible for its modulation still remain debated. In this investigation, we tackle this issue by showing how a multi-scale perspective can yield new insights. With the help of temperature-dependent statistical potentials, we analyzed some amino acid interactions at the molecular level, which are suggested to be relevant for the enhancement of thermal resistance. We then investigated the thermal stability at the protein level by quantifying its modification upon amino acid substitutions. Finally, a large scale analysis of protein stability - at the structurome level - contributed to the clarification of the relation between stability and natural evolution, thereby showing that the mutational profile of thermostable and mesostable proteins differ. Some final considerations on how the multi-scale approach could help unraveling the protein stability mechanisms are briefly discussed.


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