Directed Evolution of a Formate Dehydrogenase for Increased Tolerance to Ionic Liquids Reveals a New Site for Increasing the Stability

ChemBioChem ◽  
2014 ◽  
Vol 15 (18) ◽  
pp. 2710-2718 ◽  
Author(s):  
Julie L. L. Carter ◽  
Mourad Bekhouche ◽  
Alexandre Noiriel ◽  
Loïc J. Blum ◽  
Bastien Doumèche
Keyword(s):  
Ionic Liquids ◽  
Directed Evolution ◽  
Formate Dehydrogenase ◽  
The Stability

scholarly journals Mechanical and Electrical Performance of Flexible Polymer Film Designed for a Textile Electrically-Conductive Path

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2169
Author(s):  
Agnieszka Tabaczyńska ◽  
Anna Dąbrowska ◽  
Marcin Masłowski ◽  
Anna Strąkowska
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Surface Resistance ◽  
Conductive Filler ◽  
Extrusion Process ◽  
Electrical Performance ◽  
Electrically Conductive ◽  
Non Invasive ◽  
Flexible Polymer ◽  
The Stability

Electro-conductive paths that are mechanically resistant and stable during simulated aging cycles are promising, in relation to the non-invasive application in e-textiles in our everyday surroundings. In the paper, an analysis of the influence of electro-conductive filler, as well as ionic liquid on surface resistance is provided. Authors proved that depending on the tested variant, obtained surface resistance may vary from 50 kΩ (when 50 phr of Ag and [bmim][PF6] ionic liquid applied) to 26 GΩ (when 25 phr of Ag and [bmim][PF6] ionic liquid applied). The samples were also evaluated after simulated aging cycles and the stability of electric properties was confirmed. Moreover, it was proved that the addition of ionic liquids reduced the resistance of vulcanizates, while no significant influence of the extrusion process on conductivity was observed.

Theoretical investigation of the stability, reactivity, and the interaction of methyl-substituted peridinium-based ionic liquids

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Emmanuel A. Bisong ◽  
Hitler Louis ◽  
Tomsmith O. Unimuke ◽  
Victoria M. Bassey ◽  
John A. Agwupuye ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Electron Density ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Stabilization Energy ◽  
Basis Set ◽  
Bond Critical Point ◽  
Electronic Interaction ◽  
Donor And Acceptor ◽  
The Stability

Abstract This research work focuses on the reactivity, stability, and electronic interaction of pyridinium hydrogen nitrate (PHN)-based ionic liquids and the influence of methyl substituent on this class of ionic liquids: Ortho- (O-MPHN), meta- (M-MPHN), and para- (P-MPHN) substitution. Natural bond orbital (NBO) calculations were performed at the density functional theory (DFT) with Becke’s Lee Yang and Parr functional (B3LYP) methods and DFT/B3LYP/6-311++G(d,p) as basis set using GAUSSIAN 09W and GAUSSVIEW 6.0 software and the most important interaction between donor (Filled Lewis-type NBO’s) and the acceptor (vacant non-Lewis NBOs) were observed. From our natural bond orbital (NBO) result, it could be deduced that the higher the stabilization energy value, the greater the interaction between the donor and acceptor NBOs. The stability of the studied compounds is said to follow the order from O-MPHN > PHN > P-MPHN > M-MPHN based on the hyperconjugative interaction (stabilization energy) of the most significant interaction. The result of the highest occupied molecular orbital (HOMO), shows that PHN has the highest HOMO while the substituted derivatives have similar HOMO values between −7.70 and −7.98 eV thus PHN complex is the best electron donor while the substituted derivatives act as electron acceptors due to the presence of methyl group substituent which is observed to be electron deficient as a result of its withdrawal effect from the aromatic ring. Furthermore, the electron density, real space functions such as energy density and Laplacian of electron density at bond critical point (BCP) of the hydrogen bond interaction of the studied compounds were analyzed using Multifunctional Wavefunction analyzer software version 3.7 and it was observed that the hydrogen at position 6 and oxygen at position 11 (H6–O11) of M-methyl pyridinium nitrate with bond distance of 4.59 (Å) gave binding energy with the strongest electrostatic interaction between the cation and anion of the compounds under investigation. We also observed from our results that, substitution at the ortho position enhances the stability and strengthen the extent of charge transfer. This therefore implies that substitution at ortho position is more favorable for inter- and intramolecular interactions resulting to stabilization of the studied molecules.

6 Theoretical investigation of the stability, reactivity, and the interaction of methylsubstituted peridinium-based ionic liquids

2021 ◽  
pp. 103-118
Author(s):  
Emmanuel A. Bisong ◽  
Hitler Louis ◽  
Tomsmith O. Unimuke ◽  
Victoria M. Bassey ◽  
John A. Agwupuye ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Theoretical Investigation ◽  
The Stability

scholarly journals Ionic Liquids as Bifunctional Cosolvents Enhanced CO2 Conversion Catalysed by NADH-Dependent Formate Dehydrogenase

Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 304 ◽  
Author(s):  
Zhibo Zhang ◽  
Bao-hua Xu ◽  
Jianquan Luo ◽  
Nicolas Solms ◽  
Hongyan He ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Dft Calculations ◽  
Formic Acid ◽  
Formate Dehydrogenase ◽  
Enzymatic Reaction ◽  
Reaction System ◽  
Co2 Concentration ◽  
Co2 Conversion ◽  
Low Co2

Efficient CO2 conversion by formate dehydrogenase is limited by the low CO2 concentrations that can be reached in traditional buffers. The use of ionic liquids was proposed as a manner to increase CO2 concentration in the reaction system. It has been found, however, that the required cofactor (NADH) heavily degraded during the enzymatic reaction and that acidity was the main reason. Acidity, indeed, resulted in reduction of the conversion of CO2 into formic acid and contributed to overestimate the amount of formic acid produced when the progression of the reaction was followed by a decrease in NADH absorbance (method N). Stability of NADH and the mechanism of NADH degradation was investigated by UV, NMR and by DFT calculations. It was found that by selecting neutral–basic ionic liquids and by adjusting the concentration of the ionic liquid in the buffer, the concentration of NADH can be maintained in the reaction system with little loss. Conversion of CO2 to methanol in BmimBF4 (67.1%) was more than twice as compared with the conversion attained by the enzymatic reaction in phosphate buffer (24.3%).

Understanding the stability of polypeptide membranes in ionic liquids: a theoretical molecular dynamics study

2019 ◽  
Vol 43 (25) ◽  
pp. 10151-10161 ◽  
Author(s):  
Eyber Domingos Alves ◽  
Leonardo Bruno Assis Oliveira ◽  
Guilherme Colherinhas
Keyword(s):  
Molecular Dynamics ◽  
Ionic Liquids ◽  
Stability Analysis ◽  
Energy Storage ◽  
Ionic Solution ◽  
The Stability ◽  
New Applications

Stability analysis of polypeptide membranes in ionic liquids can make possible new applications of these membranes in energy storage and ionic solution separation.

A comparative study of the stability of stem bromelain based on the variation of anions of imidazolium-based ionic liquids

2017 ◽  
Vol 246 ◽  
pp. 178-186 ◽  
Author(s):  
Pannuru Kiran Kumar ◽  
Indrani Jha ◽  
Pannuru Venkatesu ◽  
Indra Bahadur ◽  
Eno E. Ebenso
Keyword(s):  
Ionic Liquids ◽  
Comparative Study ◽  
Stem Bromelain ◽  
The Stability

Improvement of the stability and activity of the BPO-A1 haloperoxidase from Streptomyces aureofaciens by directed evolution

2014 ◽  
Vol 192 ◽  
pp. 248-254 ◽  
Author(s):  
Ryosuke Yamada ◽  
Tatsutoshi Higo ◽  
Chisa Yoshikawa ◽  
Hideyasu China ◽  
Hiroyasu Ogino
Keyword(s):  
Directed Evolution ◽  
Streptomyces Aureofaciens ◽  
The Stability
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