Article
Chemistry, Multidisciplinary
Arkadiusz Listkowski, Natalia Masiera, Michal Kijak, Roman Luboradzki, Barbara Lesniewska, Jacek Waluk
Summary: The researchers analyzed the structural, spectroscopic, and photophysical data of six porphycenes and found a clear correlation between the strength of intramolecular NH....N hydrogen bonds and the efficiency of the nonradiative depopulation of the lowest-excited singlet state. They proposed a new model based on the delocalization of inner protons in the macrocycle cavity as responsible for nonradiative deactivation, which was confirmed by literature data for other alkyl- or aryl-substituted porphycenes.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Lixing Xia, Wenbo Huo, Huaizhi Gao, Heng Zhang, Fengming Chu, Hao Liu, Zhan'ao Tan
Summary: This study found an anomalous case where a redox active material functionalized with hydrophilic groups showed poor solubility, with further analysis revealing that intermolecular hydrogen bonds played a role in this phenomenon. Additionally, electrochemical investigations indicated that the material exhibited highly reversible electrochemical behavior and facile reaction kinetics, making it a suitable candidate for serving as a negative RAM in neutral AORFBs.
JOURNAL OF POWER SOURCES
(2021)
Article
Materials Science, Multidisciplinary
Harold Rupp, Rajesh Bhandary, Amit Kulkarni, Wolfgang Binder
Summary: This study reports the 3D-printing of supramolecular polymer electrolytes, which can compensate for volume changes dynamically. By carefully designing the mechanics and studying the rheological effects of various additives, a conductive electrode material can be printed using an extrusion process. The use of quadruple-hydrogen bonds (UPy) and LiTFSi-salts contributes to the desired properties for printability and ionic conductivities. The resulting electrolytes are printable systems with novel properties.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Chemistry, Multidisciplinary
Yaorong Chen, Hua-Chun Wang, Yongxiang Tang, Yu Zhou, Longfeng Huang, Jian Cao, Chun Tang, Manxi Zhang, Jia Shi, Junyang Liu, Xiancheng Ren, Yun-Xiang Xu, Wenjing Hong
Summary: The presence of intramolecular hydrogen bonds promotes planarization of molecular structure, leading to higher conductance by reducing dihedral twisting. This offers a new strategy for controlling molecular switches through molecular twisting.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Applied
Lianghui Gong, Shuaipeng Wang, Jingyuan Hu, Haoyang Feng, Li Zhang, Jinyue Dai, Xiaoqin Liu
Summary: Designing a reinforced and degradable vitrimer with efficient dynamic bond exchange is difficult but urgently necessary. In this study, intramolecular hydrogen bonds derived from bio-based resources were used to prepare reinforced and catalyst-free vitrimers. The resulting materials, DM-3SH and DT-3SH, showed excellent mechanical properties, recyclability, and degradation. The incorporation of intramolecular hydrogen bonds enhanced and accelerated dynamic bond exchange and degradation, contributing to the sustainable development of thermosetting resin.
PROGRESS IN ORGANIC COATINGS
(2023)
Article
Chemistry, Multidisciplinary
Nozomi Mihara, Tomonari Shimamura, Ryo Takayama, Takuya Shiga, Masayuki Nihei
Summary: Combining metal complexes with amphiphilic molecules can result in diverse functional self-assembled nanostructures. Metal complexes that undergo spin transitions are good candidates to trigger structural conversion of such assemblies due to their response to external stimuli. In this study, we investigated the structural conversion of a supramolecular assembly containing a [Co2Fe2] complex through thermally induced electron transfer-coupled spin transition (ETCST). In the presence of an amphiphilic anion, the [Co2Fe2] complex formed reverse vesicles in solution and exhibited thermal ETCST. Conversely, thermal ETCST in the presence of a bridging hydrogen-bond donor led to structural conversion from reverse vesicles to entangled one-dimensional chains through hydrogen bond formation.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Editorial Material
Chemistry, Multidisciplinary
Nozomi Mihara, Tomonari Shimamura, Ryo Takayama, Takuya Shiga, Masayuki Nihei
Summary: Combining metal complexes with amphiphilic molecules can generate a wide range of functional self-assembled nanostructures. Metal complexes with spin transitions can trigger structural conversion of these assemblies in response to various stimuli. This study investigated the structural conversion of a supramolecular assembly containing a [Co2Fe2] complex through a thermally induced electron transfer-coupled spin transition (ETCST). In the presence of an amphiphilic anion, the [Co2Fe2] complex formed reverse vesicles and exhibited thermal ETCST. However, with a bridging hydrogen-bond donor, thermal ETCST resulted in a structural conversion from reverse vesicles to entangled one-dimensional chains via hydrogen bond formation.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Engineering, Mechanical
Xizhe Zhang, Shuze Zhu
Summary: This study investigates the molecular simulation of semi-crystalline cellulose nanofibrils and finds that by tuning the semi-crystalline topologies, both the strength and toughness of the nanofibrils can be simultaneously increased. This research provides simple topology engineering strategies for designing ultra-strong and ultra-tough nanofibril and network structures, which can be extended to other material systems, enabling the design of strong and tough advanced polymeric materials.
EXTREME MECHANICS LETTERS
(2023)
Article
Polymer Science
Weiwei Wang, Haolang Liu, Li Pei, Huihui Liu, Meichen Wang, Shuiquan Li, Zhi Wang
Summary: In this study, we improved the toughness of polybenzoxazine and the surface properties of carbon fiber by incorporating newly designed and synthesized curcumin-based polyurethanes. This led to the introduction of variable amounts of hydrogen bonds and enhanced mechanical properties in both materials. The modified polybenzoxazine exhibited higher toughness and flexural strength, while the surface-modified carbon fiber reinforced benzoxazine composites showed significantly increased flexural strength. Our study not only improved the mechanical properties of these materials, but also revealed a novel method for enhancing the mechanical properties of thermosetting resins and interface adhesion of carbon fiber by regulating the hydrogen bonding content.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Junki Ochi, Kazuhiro Yuhara, Kazuo Tanaka, Yoshiki Chujo
Summary: Researchers demonstrated solid-state dual-emissive o-carborane derivatives, in which the dual-emission intensity ratios were changed by regulating intra-molecular interactions, and the overall photoluminescence spectra were estimated using the binding energy of intra-molecular interactions.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Sebastian F. Villar, Laura Corrales-Gonzalez, Belen Marquez de los Santos, Joaquin Dalla Rizza, Ari Zeida, Ana Denicola, Gerardo Ferrer-Sueta
Summary: The reduction reactions of cytosolic human peroxiredoxins (Prx) in their disulfide form by thioredoxins (Trx) were studied. The reactivity of the nucleophilic cysteine in Trx was found to be greatly affected by the formation of the Prx-Trx complex. This activation mechanism helps understand the reduction of Prx by alternative reductants involved in redox signaling.
Article
Materials Science, Multidisciplinary
Yang Liu, Li Peng, Jielong Lin, Yong Zhou, Dujin Wang, Charles C. Han, Nanbiao Ye, Xianbo Huang, Xia Dong
Summary: The mechanism of regulating hydrogen bond organization for polyamide 6,6 (PA 6,6) by nigrosine was investigated using temperature-dependent FTIR and in situ synchrotron X-ray diffraction. The study confirmed the intermolecular interaction between amide groups and nigrosine. Nigrosine promoted the formation of H-bonds in the initial stage of cooling, but hindered it at lower temperatures. The retardation effects on crystallization improved the flowability of PA 6,6 for high-speed injection molding applications.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Yuka Fukushi, Yuichi Yokochi, Ken-ichi Wakabayashi, Keisuke Yoshida, Toru Hisabori
Summary: Thioredoxin (Trx) plays a crucial role in regulating enzyme activities in chloroplasts through reducing disulfide bonds. Some stromal proteins have slow response to changes in redox condition caused by light/dark changes, while ATP synthase gamma subunit on the thylakoid membrane shows high sensitivity. The difference in redox kinetics may be determined by the localization of each protein in the chloroplast.
Article
Chemistry, Physical
Yanying Dong, Xiaofang Zhang, Yonglin Wang, Liqiu Tang, Yingkui Yang
Summary: Engineering customized active sites and microstructures in covalent organic frameworks (COFs) is an efficient way to enhance capacitive energy storage. In this study, imine-linked COFs were crafted from tri-arylamine knots and di-aldehyde linkers using Schiff-base condensation. By altering the planarity of the knots and the substitutes on the linkers, the resulting COFs exhibited enriched redox responses and diverse morphologies including nanoparticles, hollow spheres, and crystalline fibers. The study revealed that the coplanarity of building blocks and intramolecular H-bonding played a crucial role in determining the stacking modes, microstructures, and electrochemical performance of COFs. Among the studied COFs, a hydroquinone-enriched nanofiber-like COF displayed the highest specific capacitance of 235 F g(-1) at 0.5 A g(-1), surpassing previously reported COF-based electrodes due to its high planarity, intramolecular H-bonding, ultrahigh specific surface area, and abundant electroactive moieties. This work provides an alternative approach to modulating pseudocapacitive COFs by enriching redox-active centers and tuning microstructures.
JOURNAL OF POWER SOURCES
(2023)
Article
Biochemistry & Molecular Biology
Hiba Abu Hariri, Ilana Braunstein, Talal Salti, Fabian Glaser, Tal Gefen, Naama Geva-Zatorsky, Tamar Ziv, Moran Benhar
Summary: This study characterized the dynamic cysteine proteome of human macrophages and identified the role of thiol redox control in regulating inflammatory responses. The findings provide insights into the adaptability of macrophages to changing inflammatory and redox environments.
ANTIOXIDANTS & REDOX SIGNALING
(2023)
Article
Biochemistry & Molecular Biology
Marta Hammerstad, Asmund K. Rohr, Hans-Petter Hersleth
BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION
(2019)
Article
Multidisciplinary Sciences
Bastien Bissaro, Bennett Streit, Ingvild Isaksen, Vincent G. H. Eijsink, Gregg T. Beckham, Jennifer L. DuBois, Asmund K. Rohr
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2020)
Article
Multidisciplinary Sciences
Bastien Bissaro, Eirik Kommedal, Asmund K. Rohr, Vincent G. H. Eijsink
NATURE COMMUNICATIONS
(2020)
Article
Multidisciplinary Sciences
Leszek Michalak, Sabina Leanti La Rosa, Shaun Leivers, Lars Jordhoy Lindstad, Asmund Kjendseth Rohr, Finn Lillelund Aachmann, Bjorge Westereng
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2020)
Article
Biotechnology & Applied Microbiology
Anton A. Stepnov, Zarah Forsberg, Morten Sorlie, Giang-Son Nguyen, Alexander Wentzel, Asmund K. Rohr, Vincent G. H. Eijsink
Summary: The study describes a novel two-domain cellulose-active family AA10 LPMO from a marine actinomycete, and investigates the effects of the reductant and copper ions on the LPMO reaction. Results show that ascorbate-driven LPMO reactions are extremely sensitive to very low amounts of free copper, whereas reactions driven by gallic acid are almost unaffected by the presence of free copper ions.
BIOTECHNOLOGY FOR BIOFUELS
(2021)
Article
Multidisciplinary Sciences
Fatemeh Askarian, Satoshi Uchiyama, Helen Masson, Henrik Vinther Sorensen, Ole Golten, Anne Cathrine Bunaes, Sophanit Mekasha, Asmund Kjendseth Rohr, Eirik Kommedal, Judith Anita Ludviksen, Magnus O. Arntzen, Benjamin Schmidt, Raymond H. Zurich, Nina M. van Sorge, Vincent G. H. Eijsink, Ute Krengel, Tom Eirik Mollnes, Nathan E. Lewis, Victor Nizet, Gustav Vaaje-Kolstad
Summary: The Pseudomonas aeruginosa lytic polysaccharide monooxygenase CbpD is a chitin-oxidizing virulence factor that promotes bacterial survival in human blood, with its catalytic activity promoted by azurin and pyocyanin. Deletion of CbpD hinders the bacterium's ability to establish lethal systemic infection and leads to increased bacterial clearance. CbpD's key role in virulence is attributed to its ability to attenuate the terminal complement cascade in human serum.
NATURE COMMUNICATIONS
(2021)
Article
Biochemistry & Molecular Biology
Marianne Stabell, Thomas Saether, Asmund K. Rohr, Odd S. Gabrielsen, Ola Myklebost
Summary: Through methylation of a lysine residue in the KAE SUMOylation motif of HMGA2, the sequence is transformed into a consensus SUMO motif, leading to increased SUMOylation at that site. Similar methylation-dependent SUMO motifs are found in other chromatin factors, suggesting that crosstalk between methylation and SUMOylation is a general mode for regulating chromatin function.
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
(2021)
Article
Microbiology
Lars J. Lindstad, Galiana Lo, Shaun Leivers, Zijia Lu, Leszek Michalak, Gabriel V. Pereira, Asmund K. Rohr, Eric C. Martens, Lauren S. McKee, Petra Louis, Sylvia H. Duncan, Bjorge Westereng, Phillip B. Pope, Sabina Leanti La Rosa
Summary: The study demonstrates that the dominant butyrate producer Faecalibacterium prausnitzii in the human gut is able to acquire and degrade various beta-mannooligosaccharides, contributing to a more comprehensive understanding of beta-mannan metabolism and the cross-feeding interactions between beneficial microbes in the human gut. The findings highlight the importance of microbial metabolism of beta-mannans/beta-MOS as a common dietary component, offering potential insights for developing dietary formulations that may boost this beneficial symbiont and butyrate production in the gut.
Article
Biochemistry & Molecular Biology
Fredrik Gjerstad Stopamo, Asmund Kjendseth Rohr, Sophanit Mekasha, Dejan M. Petrovic, Aniko Varnai, Vincent G. H. Eijsink
Summary: The study reports the structural and functional characteristics of a single-domain AA11 LPMO from Aspergillus fumigatus. The LPMO, AfAA11A, shows substrate-binding surface features similar to those of known chitin-active LPMOs and exhibits considerable affinity for both alpha-chitin and beta-chitin, enhancing chitin degradation.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Sofie S. Kristensen, Thomas F. Oftedal, Asmund K. Rohr, Vincent G. H. Eijsink, Geir Mathiesen, Dzung B. Diep
Summary: This study investigates the molecular mechanisms underlying the interaction between RseP and Enterocin K1 (EntK1) and the bacteriocin sensitivity. Through mutational analysis, the researchers identified key regions and motifs of RseP involved in bacteriocin binding and activity. They found that the extracellular PDZ domain is the main determinant of EntK1 sensitivity. These findings may contribute to the development of novel bacteriocins and the identification of RseP as a potential antibacterial target.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Ole Golten, Ivan Ayuso-Fernandez, Kelsi R. Hall, Anton A. Stepnov, Morten Sorlie, asmund Kjendseth Rohr, Vincent G. H. Eijsink
Summary: The catalytic activity of polysaccharide-degrading mono-copper lytic polysaccharide monooxygenases (LPMOs) is affected by the choice of reductant and pH. The reaction rate with ascorbic acid is not pH-dependent between pH 6.0 and 8.0, while the reaction rate with gallic acid increases at higher pH. This correlation is attributed to the ionization state of the reductant, which affects its ability to generate H2O2 from molecular oxygen. However, l-cysteine shows a different behavior due to increased binding to the copper active site at higher pH, counteracting the increase in H2O2 production.
Article
Chemistry, Multidisciplinary
Kelsi R. Hall, Chris Joseph, Ivan Ayuso-Fernandez, Ashish Tamhankar, Lukas Rieder, Rannei Skaali, Ole Golten, Frank Neese, Asmund K. Rohr, Sergio A. V. Jannuzzi, Serena DeBeer, Vincent G. H. Eijsink, Morten Sorlie
Summary: By mutating a conserved glutamine/glutamate in Lytic polysaccharide monooxygenases (LPMOs), it was found that the nature and distance of the headgroup to the copper can fine-tune the functionality and reactivity of LPMOs. The presence of glutamate near the copper decreased the reduction potential and the ratio between reduction and reoxidation rates. These findings provide important insights for understanding LPMOs and LPMO-inspired synthetic catalysts.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Meeting Abstract
Biochemistry & Molecular Biology
G. Valerio, A. K. Rohr, J. J. G. Moura, C. Cordas
Meeting Abstract
Biochemistry & Molecular Biology
C. M. Cordas, G. N. Valerio, A. K. Rohr, V. G. H. Eijsink, J. J. G. Moura
Meeting Abstract
Chemistry, Multidisciplinary
Marta Hammerstad, Ingvild Gudim, Marie Lofstad, Kjendseth Asmund Rohr, Hans-Petter Hersleth
ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES
(2019)