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Li X, Zhang H, Lin C, Tian R, Zheng P, Hu C. Morphological Effect of Side Chain Length in Sulfonated Poly(arylene ether sulfone)s Polymer Electrolyte Membranes via Molecular Dynamics Simulation. Polymers (Basel) 2022; 14. [PMID: 36559872 DOI: 10.3390/polym14245499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
With the recognition of the multiple advantages of sulfonated hydrocarbon-based polymers that possess high chemical and mechanical stability with significant low cost, we employed molecular dynamics simulation to explore the morphological effects of side chain length in sulfonated polystyrene grafted poly(arylene ether sulfone)s (SPAES) proton exchange membranes. The calculated diffusion coefficients of hydronium ions (H3O+) are in range of 0.61-1.15 × 10-7 cm2/s, smaller than that of water molecules, due to the electrical attraction between the oppositely charged sulfonate group and H3O+. The investigation into the radial distribution functions suggests that phase segregation in the SPAES membrane is more probable with longer side chains. As the hydration level of the membranes in this study is relatively low (λ = 3), longer side chains correspond to more water molecules in the amorphous cell, which provides better solvent effects for the distribution of sulfonated side chains. The coordination number of water molecules and hydronium ions around the sulfonate group increases from 1.67 to 2.40 and from 2.45 to 5.66, respectively, with the increase in the side chain length. A significant proportion of the hydronium ions appear to be in bridging configurations coordinated by multiple sulfonate groups. The microscopic conformation of the SPAES membrane is basically unaffected by temperature during the evaluated temperature range. Thus, it can be revealed that the side chain length plays a key role in the configuration of the polymer chain and would contribute to the formation of the microphase separation morphology, which profits proton transport in the hydrophilic domains.
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Park M, Hwang S, Ju SY. The Effects of Lengths of Flavin Surfactant N-10-Alkyl Side Chains on Promoting Dispersion of a High-Purity and Diameter-Selective Single-Walled Nanotube. Nanomaterials (Basel) 2022; 12:3380. [PMID: 36234506 PMCID: PMC9565467 DOI: 10.3390/nano12193380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/17/2022] [Accepted: 09/23/2022] [Indexed: 06/16/2023]
Abstract
Flavin with defined helical self-assembly helps to understand chemical designs for obtaining high-purity semiconducting (s)-single-walled carbon nanotubes (SWNT) in a diameter (dt)-selective manner for high-end applications. In this study, flavins containing 8, 12, 16, and 20 n-alkyl chains were synthesized, and their single/tandem effects on dt-selective s-SWNT dispersibility were investigated at isomolarity. Flavins with n-dodecyl and longer chain lengths (FC12, FC16, and FC20) act as good surfactants for stable SWNT dispersions whereas n-octyl flavin (FC8) exhibits poor dispersibility owing to the lack of SWNT buoyancy. When used with small-dt SWNT, FC8 displays chirality-selective SWNT dispersion. This behavior, along with various flavin helical motifs, prompts the development of criteria for 'side chain length (lS)' required for stable and dt-selective SWNT dispersion, which also explains lS-dependent dt-enrichment behavior. Moreover, SWNT dispersions with flavins with dodecyl and longer lS exhibit increased metallic (m)-SWNT, background absorption-contributing carbonaceous impurities (CIs) and preferential selectivity of s-SWNT with slightly larger dt. The increased CIs that affect the SWNT quantum yield were attributed to a solubility parameter. Furthermore, the effects of flavin lS, sonication bath temperature, centrifugal speed, and surfactant concentration on SWNT purity and s-/m-SWNT ratio were investigated. A tandem FC8/FC12 provides fine-tuning of dt-selective SWNT dispersion, wherein the FC8 ratio governs the tendency towards smaller dt. Kinetic and thermodynamic assemblies of tandem flavins result in different sorting behaviors in which wide dt-tunability was demonstrated using kinetic assembly. This study highlights the importance of appropriate side chain length and other extrinsic parameters to obtain dt-selective or high-purity s-SWNT.
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Han AR, Kim H, Park JT, Kim JW. Characterization of a cold-adapted debranching enzyme and its role in glycogen metabolism and virulence of Vibrio vulnificus MO6-24/O. J Microbiol 2022; 60:375-386. [PMID: 35157220 DOI: 10.1007/s12275-022-1507-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/27/2021] [Accepted: 12/30/2021] [Indexed: 12/19/2022]
Abstract
Vibrio vulnificus MO6-24/O has three genes annotated as debranching enzymes or pullulanase genes. Among them, the gene encoded by VVMO6_03032 (vvde1) shares a higher similarity at the amino acid sequence level to the glycogen debranching enzymes, AmyX of Bacillus subtilis (40.5%) and GlgX of Escherichia coli (55.5%), than those encoded by the other two genes. The vvde1 gene encoded a protein with a molecular mass of 75.56 kDa and purified Vvde1 efficiently hydrolyzed glycogen and pullulan to shorter chains of maltodextrin and maltotriose (G3), respectively. However, it hydrolyzed amylopectin and soluble starch far less efficiently, and β-cyclodextrin (β-CD) only rarely. The optimal pH and temperature of Vvde1 was 6.5 and 25°C, respectively. Vvde1 was a cold-adapted debranching enzyme with more than 60% residual activity at 5°C. It could maintain stability for 2 days at 25°C and 1 day at 35°C, but it destabilized drastically at 40°C. The Vvde1 activity was inhibited considerably by Cu2+, Hg2+, and Zn2+, while it was slightly enhanced by Co2+, Ca2+, Ni2+, and Fe2+. The vvde1 knock-out mutant accumulated more glycogen than the wild-type in media supplemented with 1.0% maltodextrin; however, the side chain length distribution of glycogen was similar to that of the wild-type except G3, which was much more abundant in the mutant. Therefore, Vvde1 seemed to debranch glycogen with the degree of polymerization 3 (DP3) as the specific target branch length. Virulence of the pathogen against Caenorhabditis elegans was attenuated significantly by the vvde1 mutation. These results suggest that Vvde1 might be a unique glycogen debranching enzyme that is involved in both glycogen utilization and shaping of glycogen molecules, and contributes toward virulence of the pathogen.
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Affiliation(s)
- Ah-Reum Han
- Department of Life Sciences, Graduate School of Incheon National University, Incheon, 22102, Republic of Korea
| | - Haeyoung Kim
- Department of Life Sciences, Graduate School of Incheon National University, Incheon, 22102, Republic of Korea
| | - Jong-Tae Park
- Department of Food Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jung-Wan Kim
- Department of Life Sciences, Graduate School of Incheon National University, Incheon, 22102, Republic of Korea. .,Division of Bioengineering, Incheon National University, Incheon, 22102, Republic of Korea.
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Chang JY, Li NZ, Wang WM, Liu CT, Yu CH, Chen YC, Lu D, Lin PH, Huang CH, Kono O, Yang TY, Sun YT, Huang PY, Pan YJ, Chen TH, Liu MC, Huang SL, Huang SJ, Cheng RP. Longer charged amino acids favor β-strand formation in hairpin peptides. J Pept Sci 2021; 27:e3333. [PMID: 34114290 DOI: 10.1002/psc.3333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 04/08/2021] [Accepted: 04/13/2021] [Indexed: 11/11/2022]
Abstract
Interactions between charged amino acids significantly influence the structure and function of proteins. The encoded charged amino acids Asp, Glu, Arg, and Lys have different number of hydrophobic methylenes linking the backbone to the charged functionality. It remains to be fully understood how does this difference in the number of methylenes affect protein structure stability. Protein secondary structures are the fundamental three-dimensional building blocks of protein structures. β-Sheet structures are particularly interesting, because these structures have been associated with a number of protein misfolding diseases. Herein, we report the effect of charged amino acid side chain length at two β-strand positions individually on the stability of a β-hairpin. The charged amino acids include side chains with a carboxylate, an ammonium, or a guanidinium group. The experimental peptides, fully folded reference peptides, and fully unfolded reference peptides were synthesized by solid phase peptide synthesis and analyzed by 2D NMR methods including TOCSY, DQF-COSY, and ROESY. Sequence specific assignments were performed for all peptides. The chemical shift data were used to derive the fraction folded population and the folding free energy for the experimental peptides. Results showed that the fraction folded population increased with increasing charged amino acid side chain length. These results should be useful for developing functional peptides that adopt the β-conformation.
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Affiliation(s)
- Jing-Yuan Chang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Nian-Zhi Li
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Wei-Ming Wang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Chih-Ting Liu
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Chen-Hsu Yu
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Yan-Chen Chen
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Daniel Lu
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Pei-Hsuan Lin
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Cheng-Hsin Huang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Orika Kono
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Tzu-Yi Yang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Yi-Ting Sun
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Pei-Yu Huang
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Yen-Jin Pan
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Ting-Hsuan Chen
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Mu-Chun Liu
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Shou-Ling Huang
- Instrumentation Center, National Taiwan University, Taipei, Taiwan
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, Taipei, Taiwan
| | - Richard P Cheng
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
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Adil MA, Zhang J, Deng D, Wang Z, Yang Y, Wu Q, Wei Z. Modulation of the Molecular Orientation at the Bulk Heterojunction Interface via Tuning the Small Molecular Donor-Nonfullerene Acceptor Interactions. ACS Appl Mater Interfaces 2018; 10:31526-31534. [PMID: 30136573 DOI: 10.1021/acsami.8b08608] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The interfacial molecular packing orientation of the nonfullerene systems at the donor-acceptor interface is considered as one of the key parameters in fabricating high-performance devices because of the anisotropic molecular characteristics of conjugated donors (D) and nonfullerene acceptors (A). However, regulating the interfacial orientation for the nonfullerene systems is still scarcely studied. Herein, modulation of the interfacial molecular packing orientation of bulk heterojunction layer is successfully realized via tuning the D-A interactions. The results indicate that the molecule with relatively shorter alkyl side chain (2F-C4C6) because of weak D-A interactions is unable to influence the molecular orientation of the active layer, as compared to their longer alkyl side-chain counterpart (2F-C6C8), which demonstrates strong D-A interactions and thus efficiently modulates the overall packing orientation. The power conversion efficiencies of 6.41 and 8.23% are obtained for the relatively short and long alkyl side-chain donors with IDIC acceptor, respectively. Hence strong D-A interactions because of long enough alkyl side chain on a donor small molecule can modify the interfacial molecular packing orientation of the system, leading to a better performing device.
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Affiliation(s)
- Muhammad Abdullah Adil
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology, Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Jianqi Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology, Chinese Academy of Sciences , Beijing 100190 , China
| | - Dan Deng
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology, Chinese Academy of Sciences , Beijing 100190 , China
| | - Zhen Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology, Chinese Academy of Sciences , Beijing 100190 , China
| | - Yang Yang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology, Chinese Academy of Sciences , Beijing 100190 , China
| | - Qiong Wu
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology, Chinese Academy of Sciences , Beijing 100190 , China
| | - Zhixiang Wei
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology, Chinese Academy of Sciences , Beijing 100190 , China
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Cao PF, Naguib M, Du Z, Stacy E, Li B, Hong T, Xing K, Voylov DN, Li J, Wood DL, Sokolov AP, Nanda J, Saito T. Effect of Binder Architecture on the Performance of Silicon/Graphite Composite Anodes for Lithium Ion Batteries. ACS Appl Mater Interfaces 2018; 10:3470-3478. [PMID: 29300451 DOI: 10.1021/acsami.7b13205] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Although significant progress has been made in improving cycling performance of silicon-based electrodes, few studies have been performed on the architecture effect on polymer binder performance for lithium-ion batteries. A systematic study on the relationship between polymer architectures and binder performance is especially useful in designing synthetic polymer binders. Herein, a graft block copolymer with readily tunable architecture parameters is synthesized and tested as the polymer binder for the high-mass loading silicon (15 wt %)/graphite (73 wt %) composite electrode (active materials >2.5 mg/cm2). With the same chemical composition and functional group ratio, the graft block copolymer reveals improved cycling performance in both capacity retention (495 mAh/g vs 356 mAh/g at 100th cycle) and Coulombic efficiency (90.3% vs 88.1% at first cycle) than the physical mixing of glycol chitosan (GC) and lithium polyacrylate (LiPAA). Galvanostatic results also demonstrate the significant impacts of different architecture parameters of graft copolymers, including grafting density and side chain length, on their ultimate binder performance. By simply changing the side chain length of GC-g-LiPAA, the retaining delithiation capacity after 100 cycles varies from 347 mAh/g to 495 mAh/g.
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Affiliation(s)
| | - Michael Naguib
- Department of Physics and Engineering Physics, Tulane University , New Orleans, Louisiana 70118, United States
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Janzen D, Schaefer N, Delto C, Schindelin H, Villmann C. The GlyR Extracellular β8-β9 Loop - A Functional Determinant of Agonist Potency. Front Mol Neurosci 2017; 10:322. [PMID: 29062270 PMCID: PMC5640878 DOI: 10.3389/fnmol.2017.00322] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Accepted: 09/22/2017] [Indexed: 01/07/2023] Open
Abstract
Ligand-binding of Cys-loop receptors results in rearrangements of extracellular loop structures which are further translated into the tilting of membrane spanning helices, and finally opening of the ion channels. The cryo-EM structure of the homopentameric α1 glycine receptor (GlyR) demonstrated an involvement of the extracellular β8–β9 loop in the transition from ligand-bound receptors to the open channel state. Recently, we identified a functional role of the β8–β9 loop in a novel startle disease mouse model shaky. The mutation of residue GlyRα1Q177 to lysine present in shaky mice resulted in reduced glycine potency, reduced synaptic expression, and a disrupted hydrogen network at the structural level around position GlyRα1Q177. Here, we investigated the role of amino acid volume, side chain length, and charge at position Q177 to get deeper insights into the functional role of the β8–β9 loop. We used a combined approach of in vitro expression analysis, functional electrophysiological recordings, and GlyR modeling to describe the role of Q177 for GlyR ion channel function. GlyRα1Q177 variants do not disturb ion channel transport to the cellular surface of transfected cells, neither in homomeric nor in heteromeric GlyR configurations. The EC50 values were increased for all GlyRα1Q177 variants in comparison to the wild type. The largest decrease in glycine potency was observed for the variant GlyRα1Q177R. Potencies of the partial agonists β-alanine and taurine were also reduced. Our data are further supported by homology modeling. The GlyRα1Q177R variant does not form hydrogen bonds with the surrounding network of residue Q177 similar to the substitution with a basic lysine present in the mouse mutant shaky. Among all investigated Q177 mutants, the neutral exchange of glutamine to asparagine as well as the introduction of the closely related amino acid glutamic acid preserve the hydrogen bond network. Introduction of amino acids with small side chains or larger volume resulted in a loss of their hydrogen bonds to neighboring residues. The β8–β9 loop is thus an important structural and functional determinant of the inhibitory GlyR.
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Affiliation(s)
- Dieter Janzen
- Institute for Clinical Neurobiology, University of Würzburg, Würzburg, Germany
| | - Natascha Schaefer
- Institute for Clinical Neurobiology, University of Würzburg, Würzburg, Germany
| | - Carolyn Delto
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Hermann Schindelin
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Carmen Villmann
- Institute for Clinical Neurobiology, University of Würzburg, Würzburg, Germany
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