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Martínez-Rico O, Blanco L, Domínguez Á, González B. Accessible Eco-Friendly Method for Wastewater Removal of the Azo Dye Reactive Black 5 by Reusable Protonated Chitosan-Deep Eutectic Solvent Beads. Molecules 2024; 29:1610. [PMID: 38611889 PMCID: PMC11013712 DOI: 10.3390/molecules29071610] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/14/2024] Open
Abstract
A novel approach to enhance the utilization of low-cost and sustainable chitosan for wastewater remediation is presented in this investigation. The study centers around the modification of chitosan beads using a deep eutectic solvent composed of choline chloride and urea at a molar ratio of 1:2, followed by treatment with sulfuric acid using an impregnation accessible methodology. The effectiveness of the modified chitosan beads as an adsorbent was evaluated by studying the removal of the azo dye Reactive Black 5 (RB5) from aqueous solutions. Remarkably, the modified chitosan beads demonstrated a substantial increase in adsorption efficiency, achieving excellent removal of RB5 within the concentration range of 25-250 mg/L, ultimately leading to complete elimination. Several key parameters influencing the adsorption process were investigated, including initial RB5 concentration, adsorbent dosage, contact time, temperature, and pH. Quantitative analysis revealed that the pseudo-second-order kinetic model provided the best fit for the experimental data at lower dye concentrations, while the intraparticle diffusion model showed superior performance at higher RB5 concentration ranges (150-250 mg/L). The experimental data were successfully explained by the Langmuir isotherm model, and the maximum adsorption capacities were found to be 116.78 mg/g at 298 K and 379.90 mg/g at 318 K. Desorption studies demonstrated that approximately 41.7% of the dye could be successfully desorbed in a single cycle. Moreover, the regenerated adsorbent exhibited highly efficient RB5 removal (80.0-87.6%) for at least five consecutive uses. The outstanding adsorption properties of the modified chitosan beads can be attributed to the increased porosity, surface area, and swelling behavior resulting from the acidic treatment in combination with the DES modification. These findings establish the modified chitosan beads as a stable, versatile, and reusable eco-friendly adsorbent with high potential for industrial implementation.
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Affiliation(s)
| | | | | | - Begoña González
- Chemical Engineering Department, Universidade de Vigo, 36310 Vigo, Spain; (O.M.-R.); (L.B.); (Á.D.)
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2
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Deng Y, Liu W, Xu R, Gao R, Huang N, Zheng Y, Huang Y, Li H, Kong XY, Ye L. Reduction of Superoxide Radical Intermediate by Polydopamine for Efficient Hydrogen Peroxide Photosynthesis. Angew Chem Int Ed Engl 2024; 63:e202319216. [PMID: 38337143 DOI: 10.1002/anie.202319216] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/26/2024] [Accepted: 02/09/2024] [Indexed: 02/12/2024]
Abstract
The synthesis of hydrogen peroxide through artificial photosynthesis is a green and promising technology with advantages in sustainability, economy and safety. However, superoxide radical (⋅O2 -), an important intermediate in photocatalytic oxygen reduction to H2O2 production, has strong oxidizing properties that potentially destabilize the catalyst. Therefore, avoiding the accumulation of ⋅O2 - for its rapid conversion to H2O2 is of paramount significance in improving catalyst stability and H2O2 yield. In this work, a strategy was developed to utilize protonated groups for the rapid depletion of converted ⋅O2 -, thereby the efficiency of photocatalytic synthesis of H2O2 from CN was successfully enhanced by 47-fold. The experimental findings demonstrated that polydopamine not only improved carrier separation efficiency, and more importantly, provided the adsorption reduction active site for ⋅O2 - for efficient H2O2 production. This work offers a versatile approach for synthesizing efficient and stable photocatalysts.
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Affiliation(s)
- Yihan Deng
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic, Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, 443002, Yichang, China
| | - Wei Liu
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic, Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, 443002, Yichang, China
| | - Run Xu
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic, Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, 443002, Yichang, China
| | - Rong Gao
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic, Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, 443002, Yichang, China
| | - Niu Huang
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic, Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, 443002, Yichang, China
| | - Yong Zheng
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic, Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, 443002, Yichang, China
| | - Yingping Huang
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, 443002, Yichang, China
| | - Hao Li
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 200240, Shanghai, China
| | - Xin Ying Kong
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore, Singapore
| | - Liqun Ye
- College of Materials and Chemical Engineering, Key Laboratory of Inorganic, Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, 443002, Yichang, China
- Engineering Research Center of Eco-environment in Three Gorges Reservoir Region, Ministry of Education, China Three Gorges University, 443002, Yichang, China
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3
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Jessen C, Kornath AJ. Synthesis and Structure of Protonated Sulfur Dioxide. Angew Chem Int Ed Engl 2024:e202401953. [PMID: 38512876 DOI: 10.1002/anie.202401953] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/23/2024]
Abstract
Salts of protonated sulfur dioxide were synthesized by recrystallization of [FS(OX)2][SbF6] (X=H, D) in aprotic solvents at low temperatures. Hemiprotonated sulfur dioxide [(SO2)2H][Sb2F11] was obtained from the solvent SO2 and the monoprotonated sulfur dioxide [OSOD][Sb2F11], using 1,1,1,2-tetrafluoroethane as solvent. For both compounds, single crystals were obtained and an X-ray structure analysis was conducted. Furthermore, the salts were characterized by Raman spectroscopy and the results were discussed together with quantum chemical calculations on the M06-2X/aug-cc-pVTZ level of theory.
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Affiliation(s)
- Christoph Jessen
- Department of Chemistry, Ludwig-Maximilian University of Munich, Butenandtstr. 5-13, 81377, München, Germany
| | - Andreas J Kornath
- Department of Chemistry, Ludwig-Maximilian University of Munich, Butenandtstr. 5-13, 81377, München, Germany
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4
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Sun L, Gong Y, Che Y, Ji H, Liu B, Che Y, Zhao J. Light-Regulated Nucleation for Growing Highly Uniform Single-Crystalline Microrods. Angew Chem Int Ed Engl 2024:e202402253. [PMID: 38497168 DOI: 10.1002/anie.202402253] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/06/2024] [Accepted: 03/18/2024] [Indexed: 03/19/2024]
Abstract
We report a light-irradiation method to control the synchronous nucleation of a donor-acceptor (D-A) fluorophore for growing highly uniform single-crystalline microrods, which is in sharp contrast to the prevailing methods of restricting spontaneous nucleation and additionally adding seeds. The D-A fluorophore was observed to undergo photoinduced electron transfer to CrCl3, leading to the generation of HCl and the subsequent protonation of the D-A fluorophore. By intensifying photoirradiation or prolonging its duration, the concentration of protonated D-A fluorophores can be rapidly increased to a high supersaturation level. This results in the formation of a controlled number of nuclei in a synchronous manner, which in turn kickstart the epitaxial growth of protonated D-A fluorophores towards uniform single-crystalline microrods of controlled sizes. The light-regulated synchronous nucleation and uniform growth of microrods are a unique phenomenon that can only be achieved by specific Lewis acids, making it a novel probing method for sensitively detecting strong Lewis acids such as chromium chloride.
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Affiliation(s)
- Lishan Sun
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanjun Gong
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yanxue Che
- HT-NOVA Co., Ltd., Zhuyuan Road, Shunyi District, Beijing, 101312, China
| | - Hongwei Ji
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bing Liu
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yanke Che
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jincai Zhao
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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5
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Hariharan P, Bakhtiiari A, Liang R, Guan L. Distinct roles of the major binding residues in the cation-binding pocket of MelB. bioRxiv 2024:2024.02.27.582382. [PMID: 38464317 PMCID: PMC10925273 DOI: 10.1101/2024.02.27.582382] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Salmonella enterica serovar Typhimurium melibiose permease (MelBSt) is a prototype of the major facilitator superfamily (MFS) transporters, which play important roles in human health and diseases. MelBSt catalyzed the symport of galactosides with either H+, Li+, or Na+, but prefers the coupling with Na+. Previously, we determined the structures of the inward- and outward-facing conformation of MelBSt, as well as the molecular recognition for galactoside and Na+. However, the molecular mechanisms for H+- and Na+-coupled symport still remain poorly understood. We have solved two x-ray crystal structures of MelBSt cation-binding site mutants D59C at an unliganded apo-state and D55C at a ligand-bound state, and both structures display the outward-facing conformations virtually identical as published previously. We determined the energetic contributions of three major Na+-binding residues in cation selectivity for Na+ and H+ by the free energy simulations. The D55C mutant converted MelBSt to a solely H+-coupled symporter, and together with the free-energy perturbation calculation, Asp59 is affirmed to be the sole protonation site of MelBSt. Unexpectedly, the H+-coupled melibiose transport with poor activities at higher ΔpH and better activities at reversal ΔpH was observed, supporting that the membrane potential is the primary driving force for the H+-coupled symport mediated by MelBSt. This integrated study of crystal structure, bioenergetics, and free energy simulations, demonstrated the distinct roles of the major binding residues in the cation-binding pocket.
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Affiliation(s)
- Parameswaran Hariharan
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX
| | | | - Ruibin Liang
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX
| | - Lan Guan
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX
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Kondoh A, Ojima R, Ishikawa S, Terada M. Construction of 1,3-Nonadjacent Stereogenic Centers Through Enantioselective Addition of α-Thioacetamides to α-Substituted Vinyl Sulfones Catalyzed by Chiral Strong Brønsted Base. Adv Sci (Weinh) 2024; 11:e2308020. [PMID: 38126668 PMCID: PMC10916638 DOI: 10.1002/advs.202308020] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/07/2023] [Indexed: 12/23/2023]
Abstract
An enantioselective addition reaction for the construction of 1,3-nonadjacent stereogenic centers is developed by means of a chiral strong Brønsted base catalyst. The chiral sodium ureate catalyst efficiently promoted the reaction of α-thioacetamides as less acidic pronucleophiles with vinyl sulfones having a variety of α-substituents including aryl, alkyl and halo groups, and α-phenylacrylates, accomplishing the construction of various 1,3-nonadjacent stereogenic centers in highly diastereo- and enantioselective manners. This is a rare example of the construction of 1,3-nonadjacent stereogenic centers with less acidic pronucleophiles. In addition, the application of Michael acceptors having various types of α-substituents in a single catalyst system is achieved for the first time, demonstrating the utility of the present catalyst system for the construction of 1,3-nonadjacent stereogenic centers.
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Affiliation(s)
- Azusa Kondoh
- Research and Analytical Center for Giant MoleculesGraduate School of ScienceTohoku UniversityAramaki, Aoba‐kuSendai980–8578Japan
| | - Rihaku Ojima
- Department of ChemistryGraduate School of ScienceTohoku UniversityAramaki, Aoba‐kuSendai980–8578Japan
| | - Sho Ishikawa
- Department of ChemistryGraduate School of ScienceTohoku UniversityAramaki, Aoba‐kuSendai980–8578Japan
| | - Masahiro Terada
- Department of ChemistryGraduate School of ScienceTohoku UniversityAramaki, Aoba‐kuSendai980–8578Japan
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7
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Axelsson M, Xia Z, Wang S, Cheng M, Tian H. Role of the Benzothiadiazole Unit in Organic Polymers on Photocatalytic Hydrogen Production. JACS Au 2024; 4:570-577. [PMID: 38425933 PMCID: PMC10900483 DOI: 10.1021/jacsau.3c00681] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/22/2023] [Accepted: 01/02/2024] [Indexed: 03/02/2024]
Abstract
Organic polymers based on the donor-acceptor structure are a promising class of efficient photocatalysts for solar fuel production. Among these polymers, poly(9,9-dioctylfluorene-alt-1,2,3-benzothiadiazole) (PFBT) consisting of fluorene donor and benzothiadiazole acceptor units has shown good photocatalytic activity when it is prepared into polymer dots (Pdots) in water. In this work, we investigate the effect of the chemical environment on the activity of photocatalysis from PFBT Pdots for hydrogen production. This is carried out by comparing the samples with various concentrations of palladium under different pH conditions and with different sacrificial electron donors (SDs). Moreover, a model compound 1,2,3-benzothiadiazole di-9,9-dioctylfluorene (BTDF) is synthesized to investigate the mechanism for protonation of benzothiadiazole and its kinetics in the presence of an organic acid-salicylic acid by cyclic voltammetry. We experimentally show that benzothiadiazole in BTDF can rapidly react with protons with a fitted value of 0.1-5 × 1010 M-1 s-1 which should play a crucial role in the photocatalytic reaction with a polymer photocatalyst containing benzothiadiazole such as PFBT Pdots for hydrogen production in acidic conditions. This work gives insights into why organic polymers with benzothiadiazole work efficiently for photocatalytic hydrogen production.
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Affiliation(s)
- Martin Axelsson
- Department
of Chemistry-Ångström Laboratory, Uppsala University, Uppsala 75120, Sweden
| | - Ziyang Xia
- Institute
for Energy Research, Jiangsu University, Zhenjiang 212013, China
| | - Sicong Wang
- Department
of Chemistry-Ångström Laboratory, Uppsala University, Uppsala 75120, Sweden
| | - Ming Cheng
- Institute
for Energy Research, Jiangsu University, Zhenjiang 212013, China
| | - Haining Tian
- Department
of Chemistry-Ångström Laboratory, Uppsala University, Uppsala 75120, Sweden
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8
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Clarke A, Farr CV, El‐Kasaby A, Szöllősi D, Freissmuth M, Sucic S, Stockner T. Probing binding and occlusion of substrate in the human creatine transporter-1 by computation and mutagenesis. Protein Sci 2024; 33:e4842. [PMID: 38032325 PMCID: PMC10751730 DOI: 10.1002/pro.4842] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 11/16/2023] [Accepted: 11/18/2023] [Indexed: 12/01/2023]
Abstract
In chordates, energy buffering is achieved in part through phosphocreatine, which requires cellular uptake of creatine by the membrane-embedded creatine transporter (CRT1/SLC6A8). Mutations in human slc6a8 lead to creatine transporter deficiency syndrome, for which there is only limited treatment. Here, we used a combined homology modeling, molecular dynamics, and experimental approach to generate a structural model of CRT1. Our observations support the following conclusions: contrary to previous proposals, C144, a key residue in the substrate binding site, is not present in a charged state. Similarly, the side chain D458 must be present in a protonated form to maintain the structural integrity of CRT1. Finally, we identified that the interaction chain Y148-creatine-Na+ is essential to the process of occlusion, which occurs via a "hold-and-pull" mechanism. The model should be useful to study the impact of disease-associated point mutations on the folding of CRT1 and identify approaches which correct folding-deficient mutants.
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Affiliation(s)
- Amy Clarke
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
| | - Clemens V. Farr
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
| | - Ali El‐Kasaby
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
| | - Daniel Szöllősi
- Department of Theoretical and Computational BiophysicsMax Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
| | - Sonja Sucic
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
| | - Thomas Stockner
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and PharmacologyMedical University of ViennaViennaAustria
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Zhang J, Yuan C, Dou H, Zhu R, Li L, Weng TC. Unveiling Carrier Relaxation Mechanism in Protonated/Deprotonated Carbon Dots and Their Solvent Effects via Ultrafast Spectroscopy. Chem Asian J 2023:e202301082. [PMID: 38155528 DOI: 10.1002/asia.202301082] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/28/2023] [Accepted: 12/28/2023] [Indexed: 12/30/2023]
Abstract
The intricate nature of the surface structure of carbon dots (CDs) hinders a comprehensive understanding of their emission behavior. In this study, we employ two types of CDs created through acid-alkali treatments, one with surface protonation and the other with surface deprotonation, with the objective of investigating the impact of these surface modifications on carrier behavior using ultrafast spectroscopy techniques. TEM, XRD, FTIR and Raman spectra demonstrate the CDs' structure, featuring graphitic core and abundant surface functional groups. XPS confirms the successful surface modifications of CDs via protonation and deprotonation. Ultrafast transient absorption (TA) spectroscopy reveals that deprotonation modification may decelerate the relaxation process, thereby increasing the visible PL quantum yields (PLQY). Conversely, protonation may accelerate the relaxation process due to the induced low-energy absorption band, resulting in self-absorption and reduced PLQY. Furthermore, TA analysis of CDs in mixed solvents with different proportions of ethanol shows the beneficial effect of ethanol in decelerating the relaxation process, leading to an increased PLQY of 33.7 % for deprotonated CDs and 22.1 % for protonated CDs. This study illuminates the intricate relationship between surface deprotonation/protonation modifications and carrier behavior in CDs, offering a potential avenue for the design of high-brightness CDs for diverse applications.
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Affiliation(s)
- Jihao Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
| | - Chunze Yuan
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
| | - Hongbin Dou
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
| | - Ruixue Zhu
- Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
| | - Lin Li
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
| | - Tsu-Chien Weng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Center for Transformative Science, ShanghaiTech University, Shanghai, 201210, China
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10
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Xiao B, Zheng Y, Song M, Liu X, Lee GH, Omenya F, Yang X, Engelhard MH, Reed D, Yang W, Amine K, Xu GL, Balbuena PB, Li X. Protonation Stimulates the Layered to Rock Salt Phase Transition of Ni-Rich Sodium Cathodes. Adv Mater 2023:e2308380. [PMID: 38134206 DOI: 10.1002/adma.202308380] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/21/2023] [Indexed: 12/24/2023]
Abstract
Protonation of oxide cathodes triggers surface transition metal dissolution and accelerates the performance degradation of Li-ion batteries. While strategies are developed to improve cathode material surface stability, little is known about the effects of protonation on bulk phase transitions in these cathode materials or their sodium-ion battery counterparts. Here, using NaNiO2 in electrolytes with different proton-generating levels as model systems, a holistic picture of the effect of incorporated protons is presented. Protonation of lattice oxygens stimulate transition metal migration to the alkaline layer and accelerates layered-rock-salt phase transition, which leads to bulk structure disintegration and anisotropic surface reconstruction layers formation. A cathode that undergoes severe protonation reactions attains a porous architecture corresponding to its multifold performance fade. This work reveals that interactions between electrolyte and cathode that result in protonation can dominate the structural reversibility/stability of bulk cathodes, and the insight sheds light for the development of future batteries.
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Affiliation(s)
- Biwei Xiao
- Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Yu Zheng
- Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843-3122, USA
- Department of Chemistry, Texas A&M University, College Station, TX, 77843-3122, USA
| | - Miao Song
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Xiang Liu
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL, 60439, USA
| | - Gi-Hyeok Lee
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Department of Materials Science and Engineering, Dongguk University, Seoul, 04620, Republic of Korea
| | - Fred Omenya
- Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Xin Yang
- Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Mark H Engelhard
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - David Reed
- Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Wanli Yang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Khalil Amine
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL, 60439, USA
| | - Gui-Liang Xu
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL, 60439, USA
| | - Perla B Balbuena
- Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843-3122, USA
- Department of Chemistry, Texas A&M University, College Station, TX, 77843-3122, USA
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843-3122, USA
| | - Xiaolin Li
- Energy & Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
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Abstract
Ion injection controlled by an electric field is a powerful method to manipulate the diverse physical and chemical properties of metal oxides. However, the dynamic control of ion concentrations and their correlations with lattices in perovskite systems have not been fully understood. In this study, we systematically demonstrate the electric-field-controlled protonation of La2/3Sr1/3MnO3 (LSMO) films. The rapid and room-temperature protonation induces a colossal lattice expansion of 9.35% in tensile-strained LSMO, which is crucial for tailoring material properties and enabling a wide range of applications in advanced electronics, energy storage, and sensing technologies. This large expansion in the lattice is attributed to the higher degree of proton diffusion, resulting in a significant elongation in the Mn-O bond and octahedral tilting, which is supported by results from density functional theory calculations. Interestingly, such a colossal expansion is not observed in LSMO under compressive strain, indicating the close dependence of ion-electron-lattice coupling on strain states. These efficient modulations of the lattice and magnetoelectric functionalities of LSMO via proton diffusion offer a promising avenue for developing multifunctional iontronic devices.
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Affiliation(s)
- Muhammad Umer Fayaz
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Qian Wang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Shixuan Liang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Lei Han
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
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12
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Fraczkiewicz R. Can an Amine Be a Weaker and a Stronger Base at the Same Time? Curious Cases of Chameleonic Ionization. ACS Phys Chem Au 2023; 3:512-514. [PMID: 38034037 PMCID: PMC10683473 DOI: 10.1021/acsphyschemau.3c00029] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 12/02/2023]
Abstract
We discovered an anomalous basic dissociation in certain multiprotic compounds. An amine group placed in the middle of a given compound is predicted to behave unusually-at certain pH ranges, its averaged degree of protonation actually increases with pH (!) resulting from interactions with other ionizable groups. This chameleonic behavior results in two pK50 values: one corresponding to a weaker base and the other to a stronger base for the same group.
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Affiliation(s)
- Robert Fraczkiewicz
- Simulations
Plus, Inc. 42505 10th Street West, Lancaster, California 93534, United States
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13
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Ptushenko VV, Knorre DD, Glagoleva ES. The Photoprotective Protein PsbS from Green Microalga Lobosphaera incisa: The Amino Acid Sequence, 3D Structure and Probable pH-Sensitive Residues. Int J Mol Sci 2023; 24:15060. [PMID: 37894741 PMCID: PMC10606523 DOI: 10.3390/ijms242015060] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/04/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
PsbS is one of the key photoprotective proteins, ensuring the tolerance of the photosynthetic apparatus (PSA) of a plant to abrupt changes in irradiance. Being a component of photosystem II, it provides the formation of quenching centers for excited states of chlorophyll in the photosynthetic antenna with an excess of light energy. The signal for "turning on" the photoprotective function of the protein is an excessive decrease in pH in the thylakoid lumen occurring when all the absorbed light energy (stored in the form of transmembrane proton potential) cannot be used for carbon assimilation. Hence, lumen-exposed protonatable amino acid residues that could serve as pH sensors are the essential components of PsbS-dependent photoprotection, and their pKa values are necessary to describe it. Previously, calculations of the lumen-exposed protonatable residue pKa values in PsbS from spinach were described in the literature. However, it has recently become clear that PsbS, although typical of higher plants and charophytes, can also provide photoprotection in green algae. Namely, the stress-induced expression of PsbS was recently shown for two green microalgae species: Chlamydomonas reinhardtii and Lobosphaera incisa. Therefore, we determined the amino acid sequence and modeled the three-dimensional structure of the PsbS from L. incisa, as well as calculated the pKa values of its lumen-exposed protonatable residues. Despite significant differences in amino acid sequence, proteins from L. incisa and Spinacia oleracea have similar three-dimensional structures. Along with the other differences, one of the two pH-sensing glutamates in PsbS from S. oleracea (namely, Glu-173) has no analogue in L. incisa protein. Moreover, there are only four glutamate residues in the lumenal region of the L. incisa protein, while there are eight glutamates in S. oleracea. However, our calculations show that, despite the relative deficiency in protonatable residues, at least two residues of L. incisa PsbS can be considered probable pH sensors: Glu-87 and Lys-196.
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Affiliation(s)
- Vasily V. Ptushenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Dmitry D. Knorre
- Faculty of Computational Mathematics and Cybernetics, Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Elena S. Glagoleva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
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14
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Ji Z, Zhai B, Wang N, He Y, Wang H, Fei G, Wang C, Zhang G, Shao L. Transferring and Retaining of Different Polyaniline Nanofeatures via Electrophoretic Deposition for Enhanced Sensing Performance. Small 2023; 19:e2300182. [PMID: 36828796 DOI: 10.1002/smll.202300182] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/05/2023] [Indexed: 05/25/2023]
Abstract
Nanofeatured polyaniline (PANI) electrodes have demonstrated impressive sensing performance due to the enhanced electrolyte diffusion and ion transport. However, the retaining of these nanostructures on substrates via electrophoretic deposition (EPD) faces an insurmountable challenge from the involved dedoping process. Here, camphorsulfonic acid is utilized with high steric effects to dope PANI (PANI-CSA) that can be directly used EPD without involving a dedoping process. Five different nanofeatures (sea cucumber-like, nanofiber, amorphous, nanotube, and nanorod) are synthesized, and they have been all successfully transferred onto indium tin oxide substrate in a formic acid/acetonitrile system, namely a morphology memory effect. The mechanism of retaining these nanofeatures is revealed, which is realized via the processes of dissolution of PANI-CSA, codoping and solvation, and reassembly of basic units into the original nanofeature. The enhanced protonation level by the codoping of formic acid and solvation of acetonitrile plays the key role in retaining these nanofeatures. This method is also applicable to transfer PANI/gold nanorod composites (PANI-CSA/AuNRs). The PANI-CSA/AuNRs electrode as an ascorbic acid sensor has shown an excellent sensing performance with a sensitivity up to 872.7 µA mm-1 cm-2 and a detection limit of as low as 0.18 × 10-6 m.
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Affiliation(s)
- Zhanyou Ji
- College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, P. R. China
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China
- Xi'an Key Laboratory of Green Chemicals and Functional Materials, Shaanxi University of Science and Technology, Xi'an, 710021, China
| | - Bingyan Zhai
- College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, P. R. China
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China
| | - Nana Wang
- College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, P. R. China
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China
| | - Yinkun He
- College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, P. R. China
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China
| | - Huidi Wang
- College of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China
| | - Guiqiang Fei
- College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, P. R. China
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China
| | - Caiyun Wang
- Intelligent Polymer Research Institute, ARC Centre of Excellence for Electromaterials Science, AIIM Facility, Innovation Campus, University of Wollongong, North Wollongong, NSW 2500, Australia
| | - Guohong Zhang
- Department of Machine Engineering, Faculty of Systems Science and Technology, Akita Prefectural University, Yurihonjo city, Akita, 015-0055, Japan
| | - Liang Shao
- College of Chemistry and Chemical Engineering, Shaanxi Key Laboratory of Chemical Additives for Industry, Shaanxi University of Science and Technology, Xi'an, Shaanxi, 710021, P. R. China
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi'an, 710021, P. R. China
- Xi'an Key Laboratory of Green Chemicals and Functional Materials, Shaanxi University of Science and Technology, Xi'an, 710021, China
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15
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Conrad M, Horn AHC, Sticht H. Computational Analysis of Histamine Protonation Effects on H 1R Binding. Molecules 2023; 28:molecules28093774. [PMID: 37175183 PMCID: PMC10180022 DOI: 10.3390/molecules28093774] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Despite numerous studies investigating histamine and its receptors, the impact of histamine protonation states on binding to the histamine H1-receptor (H1R) has remained elusive. Therefore, we assessed the influence of different histamine tautomers (τ-tautomer, π-tautomer) and charge states (mono- vs. dicationic) on the interaction with the ternary histamine-H1R-Gq complex. In atomistic molecular dynamics simulations, the τ-tautomer formed stable interactions with the receptor, while the π-tautomer induced a rotation of the histamine ring by 180° and formed only weaker hydrogen bonding interactions. This suggests that the τ-tautomer is more relevant for stabilization of the active ternary histamine-H1R-Gq complex. In addition to the two monocationic tautomers, the binding of dicationic histamine was investigated, whose interaction with the H1R had been observed in a previous experimental study. Our simulations showed that the dication is less compatible with the ternary histamine-H1R-Gq complex and rather induces an inactive conformation in the absence of the Gq protein. Our data thus indicate that the charge state of histamine critically affects its interactions with the H1R. Ultimately these findings might have implications for the future development of new ligands that stabilize distinct H1R activation states.
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Affiliation(s)
- Marcus Conrad
- Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Anselm H C Horn
- Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
- Erlangen National High Performance Computing Center (NHR@FAU), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - Heinrich Sticht
- Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
- Erlangen National High Performance Computing Center (NHR@FAU), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
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16
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AbuSalim DI, Lash TD. Aromatic Character and Relative Stability of Pyrazoloporphyrin Tautomers and Related Protonated Species: Insights into How Pyrazole Changes the Properties of Carbaporphyrinoid Systems. Molecules 2023; 28:molecules28062854. [PMID: 36985826 PMCID: PMC10056226 DOI: 10.3390/molecules28062854] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/12/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
Pyrazoloporphyrins (PzPs), which are porphyrin analogues incorporating a pyrazole subunit, are examples of carbaporphyrin-type structures with a carbon atom within the macrocyclic cavity. DFT calculations were used to assess a series of 17 PzP tautomers, nine monoprotonated species and four related diprotonated PzP dications. The geometries of the structures were optimized using M06-2X/6-311++G(d,p), and the relative stabilities computed with the cc-PVTZ functional. Nucleus independent chemical shifts, both NICS(0) and NICS(1)zz, were calculated, and the anisotropy of the induced current density (AICD) plots were generated for all of the species under investigation. The results for free base PzPs show that fully aromatic PzP tautomers are not significantly more stable than weakly aromatic cross-conjugated species. In addition, strongly aromatic structures with internal CH2's are much less stable, a feature that is also seen for protonated PzPs. The degree of planarity for the individual macrocycles does not significantly correlate with the stability of these structures. The results allow significant aromatic conjugation pathways to be identified in many cases, and provide insights into the aromatic properties of this poorly studied system. These investigations also complement experimental results for PzPs and emphasize the need for further studies in this area.
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Affiliation(s)
- Deyaa I AbuSalim
- Department of Chemistry, Illinois State University, Normal, IL 61790-4160, USA
| | - Timothy D Lash
- Department of Chemistry, Illinois State University, Normal, IL 61790-4160, USA
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17
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Nakamura T, Koga-Ogawa Y, Fujimiya K, Chirifu M, Goto M, Ikemizu S, Nakabeppu Y, Yamagata Y. Protonation states of Asp residues in the human Nudix hydrolase MTH1 contribute to its broad substrate recognition. FEBS Lett 2023. [PMID: 36914375 DOI: 10.1002/1873-3468.14611] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/17/2023] [Accepted: 03/03/2023] [Indexed: 03/14/2023]
Abstract
Human MutT homolog 1 (MTH1), also known as Nudix-type motif 1 (NUDT1), hydrolyzes 8-oxo-dGTP and 2-oxo-dATP with broad substrate recognition and has attracted attention in anticancer therapeutics. Previous studies on MTH1 have proposed that the exchange of the protonation state between Asp119 and Asp120 is essential for the broad substrate recognition of MTH1. To understand the relationship between protonation states and substrate binding, we determined the crystal structures of MTH1 at pH 7.7-9.7. With increasing pH, MTH1 gradually loses its substrate-binding ability, indicating that Asp119 is deprotonated at pH 8.0-9.1 in 8-oxo-dGTP recognition and Asp120 is deprotonated at pH 8.6-9.7 in 2-oxo-dATP recognition. These results confirm that MTH1 recognizes 8-oxo-dGTP and 2-oxo-dATP by exchanging the protonation state between Asp119 and Asp120 with higher pKa .
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Affiliation(s)
- Teruya Nakamura
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Japan
- Priority Organization for Innovation and Excellence, Kumamoto University, Japan
| | - Yukari Koga-Ogawa
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Japan
- Faculty of Health Sciences, Nihon Institute of Medical Science, Saitama, Japan
| | | | - Mami Chirifu
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Japan
| | | | - Shinji Ikemizu
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Japan
| | - Yusaku Nakabeppu
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Yuriko Yamagata
- Graduate School of Pharmaceutical Sciences, Kumamoto University, Japan
- Shokei University and Shokei University Junior College, Kumamoto, Japan
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18
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Chen W, Liu S, Ren Y, Xie S, Yan C, Zhou Z, Zhou G. Conjugation Extension and Halochromic Behaviors of S-Fused Polycyclic Aromatic Hydrocarbons Bearing Cyclopenta[b]thiopyran Moieties. Chemistry 2023; 29:e202203238. [PMID: 36376244 DOI: 10.1002/chem.202203238] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/12/2022] [Accepted: 11/14/2022] [Indexed: 11/16/2022]
Abstract
Three S-fused polycyclic aromatic hydrocarbons (PAHs) bearing cyclopenta[b]thiopyran moieties have been designed and successfully synthesized. With the conjugation extension, the absorption onset of the longest PAH reaches 1110 nm. All the three S-fused PAHs exhibit significant halochromic properties in both solution and solid states. Upon protonation, the proton is incorporated on the cyclopentadiene ring while the positive charge is localized on the thiopyrylium ring. Moreover, no significant difference can be found for the two shorter PAHs upon the protonation by different organic acids, such as trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TfOH), while the longest PAH can be only mono-protonated by TFA but di-protonated by stronger TfOH. Furthermore, after protonation, the non-emissive S-fused PAHs exhibit strong fluorescence and can be regenerated by simply neutralization with triethylamine. The enhanced emission of mono-protonated products stem from S2 →S0 transitions, which disobey the Kasha's rule.
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Affiliation(s)
- Weinan Chen
- Lab of Advanced Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200438, P. R. China
| | - Si Liu
- Lab of Advanced Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200438, P. R. China
| | - Yingjian Ren
- Lab of Advanced Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200438, P. R. China
| | - Shoudong Xie
- Lab of Advanced Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200438, P. R. China
| | - Chuan Yan
- Lab of Advanced Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200438, P. R. China
| | - Zhanglang Zhou
- Lab of Advanced Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200438, P. R. China
| | - Gang Zhou
- Lab of Advanced Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200438, P. R. China
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19
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Muhasina PV, Parameswaran P. σ versus π-radical: Tuning the electronic nature of neutral carbon (I) compounds with three non-bonding electrons. J Comput Chem 2023; 44:422-431. [PMID: 35802539 DOI: 10.1002/jcc.26964] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 06/17/2022] [Accepted: 06/19/2022] [Indexed: 12/31/2022]
Abstract
The bonding and reactivity of the hypo-coordinated compounds with one, two, and four non-bonding electrons namely, carbon-centered free radical, carbenes, and carbones were well earlier established. Here, we report stability, bonding and reactivity of compounds RCL, where R is one-electron donor group (R = CH3 (a), CHO (b), and NO2 (c)) and L is two-electron donor ligand (L = cAAC (1), CO (2), NHC (3) and PMe3 (4)), having three non-bonding electrons. The ground states of molecules exist in a doublet with a lone pair of electrons and an unpaired electron at the central carbon atom (C1). The spin hops over from π- to σ-type orbitals is observed as the π-acceptor strength of the donor ligand increases. The replacement of the methyl group by CHO and NO2 indicate that the cAAC and CHO substituted compounds gives a σ-radical except in compound 2c. These molecules show very high proton affinity and exothermic reaction energy for the hydrogen atom addition indicating dual reactivity namely, radical and lone pair reactivity.
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20
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Rahrt R, Koszinowski K. C versus O Protonation in Zincate Anions: A Simple Gas-Phase Model for the Surprising Kinetic Stability of Organometallics. Chemistry 2023; 29:e202203611. [PMID: 36692992 DOI: 10.1002/chem.202203611] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/18/2023] [Accepted: 01/24/2023] [Indexed: 01/25/2023]
Abstract
For better understanding the intrinsic reactivity of organozinc reagents, we have examined the protolysis of the isolated zincate ions Et3 Zn- , Et2 Zn(OH)- , and Et2 Zn(OH)2 Li- by 2,2,2-trifluoroethanol in the gas phase. The protonation of the hydroxy groups and the release of water proceed much more efficiently than the protonation of the ethyl groups and the liberation of ethane. Quantum-chemical computations and statistical-rate theory calculations fully reproduce the experimental findings and attribute the lower reactivity of the more basic ethyl moiety to higher intrinsic barriers, which override the thermodynamic preference for its protonation. Thus, our minimalistic gas-phase model provides evidence for the intrinsically low reactivity of organozinc reagents toward proton donors and helps to explain their remarkable kinetic stability against moisture and even protic media.
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Affiliation(s)
- Rene Rahrt
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
| | - Konrad Koszinowski
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
- Wöhler Research Institute for Sustainable Chemistry, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany
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21
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Santos LH, Caffarena ER, Ferreira RS. pH and non-covalent ligand binding modulate Zika virus NS2B/NS3 protease binding site residues: Discoveries from MD and constant pH MD simulations. J Biomol Struct Dyn 2022; 40:10359-10372. [PMID: 34180376 DOI: 10.1080/07391102.2021.1943528] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Zika virus (ZIKV) is a global health concern and has been linked to severe neurological pathologies. Although no medication is available yet, many efforts to develop antivirals and host cell binding inhibitors led to attractive drug-like scaffolds, mainly targeting the nonstructural NS2B/NS3 protease (NS2B/NS3pro). NS2B/NS3pro active site has several titratable residues susceptible to pH changes and ligand binding; hence, understanding these residues' protonation is essential to drug design efforts targeting the active site. Here we use in silico methods to probe non-covalent binding and its effect on pKa shifts of the active site residues on a ligand-free protease and with a non-peptidic competitive inhibitor (Ki=13.5 µM). By applying constant pH molecular dynamics, we found that the catalytic residues of the unbound NS2B/NS3pro achieved the protonation needed for the serine protease mechanism over the pH value of 8.5. Nevertheless, the protease in the holo state achieved this same scenario at lower pH values. Also, non-covalent binding affected the catalytic triad (H51, D75, and S135) by stabilizing their distances and interaction network. Thus, NS2B/NS3pro residues configuration for activity might be both pH-dependent and influenced by ligand binding. However, compound presence within the binding site destabilized the NS2B, interfering with the closed and active conformation necessary for substrate binding and catalysis. Our outcomes provide valuable insights into non-covalent inhibitor behavior and its effect on protease active site residues, impacting optimization and design of novel compounds. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Lucianna H Santos
- Laboratório de Modelagem Molecular e Planejamento de Fármacos, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ernesto R Caffarena
- Grupo de Biofísica Computacional e Modelagem Molecular, Programa de Computação Científica, Fiocruz, Rio de Janeiro, Brazil
| | - Rafaela S Ferreira
- Laboratório de Modelagem Molecular e Planejamento de Fármacos, Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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22
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Aksenova I, Pomogaev V. Stability of Dibromo-Dipyrromethene Complexes Coordinated with B, Zn, and Cd in Solutions of Various Acidities. Molecules 2022; 27:molecules27248815. [PMID: 36557945 PMCID: PMC9784619 DOI: 10.3390/molecules27248815] [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] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/08/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022] Open
Abstract
The spectral luminescent properties of dipyrromethenates halogenated with bromine on both ends of the long axis and coordinated using boron fluoride, zinc, or cadmium in neutral ethanol and acidified with hydrochloric acid solutions were studied. The constants of the acid-base equilibrium of the complexes in the proton-donor solvents in the ground and excited states was determined. The mechanisms of complex protonation were discussed, depending on the structure of the compounds. The electronic structures of the neutral and protonated compounds were modeled and analyzed based on the quantum-chemical method. The structures and spectral-luminescence properties were calculated using the SMD model of ethanol solvent using the TD-DFT theory with the B3LYP functional and the composite def2-SVP/def2-TZVP/def2-TZVPP_ECP basis sets, depending on the atomic number of the elements.
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23
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Joutsuka T, Nanasawa R, Igarashi K, Horie K, Sugishima M, Hagiwara Y, Wada K, Fukuyama K, Yano N, Mori S, Ostermann A, Kusaka K, Unno M. Neutron crystallography and quantum chemical analysis of bilin reductase PcyA mutants reveal substrate and catalytic residue protonation states. J Biol Chem 2022; 299:102763. [PMID: 36463961 PMCID: PMC9800206 DOI: 10.1016/j.jbc.2022.102763] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Revised: 11/16/2022] [Accepted: 11/29/2022] [Indexed: 12/04/2022] Open
Abstract
PcyA, a ferredoxin-dependent bilin pigment reductase, catalyzes the site-specific reduction of the two vinyl groups of biliverdin (BV), producing phycocyanobilin. Previous neutron crystallography detected both the neutral BV and its protonated form (BVH+) in the wildtype (WT) PcyA-BV complex, and a nearby catalytic residue Asp105 was found to have two conformations (protonated and deprotonated). Semiempirical calculations have suggested that the protonation states of BV are reflected in the absorption spectrum of the WT PcyA-BV complex. In the previously determined absorption spectra of the PcyA D105N and I86D mutants, complexed with BV, a peak at 730 nm, observed in the WT, disappeared and increased, respectively. Here, we performed neutron crystallography and quantum chemical analysis of the D105N-BV and I86D-BV complexes to determine the protonation states of BV and the surrounding residues and study the correlation between the absorption spectra and protonation states around BV. Neutron structures elucidated that BV in the D105N mutant is in a neutral state, whereas that in the I86D mutant is dominantly in a protonated state. Glu76 and His88 showed different hydrogen bonding with surrounding residues compared with WT PcyA, further explaining why D105N and I86D have much lower activities for phycocyanobilin synthesis than the WT PcyA. Our quantum mechanics/molecular mechanics calculations of the absorption spectra showed that the spectral change in D105N arises from Glu76 deprotonation, consistent with the neutron structure. Collectively, our findings reveal more mechanistic details of bilin pigment biosynthesis.
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Affiliation(s)
- Tatsuya Joutsuka
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan,Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan,For correspondence: Tatsuya Joutsuka; Masaki Unno
| | - Ryota Nanasawa
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan
| | - Keisuke Igarashi
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan
| | - Kazuki Horie
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan
| | - Masakazu Sugishima
- Department of Medical Biochemistry, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Yoshinori Hagiwara
- Department of Biochemistry and Applied Chemistry, National Institute of Technology, Kurume College, Kurume, Fukuoka, Japan
| | - Kei Wada
- Department of Medical Sciences, University of Miyazaki, Miyazaki, Miyazaki, Japan
| | - Keiichi Fukuyama
- Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan
| | - Naomine Yano
- Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan
| | - Seiji Mori
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan,Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan
| | - Andreas Ostermann
- Heinz Maier-Leibnitz Zentrum (MLZ), Technical University Munich, Garching, Germany
| | - Katsuhiro Kusaka
- Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan
| | - Masaki Unno
- Graduate School of Science and Engineering, Ibaraki University, Hitachi, Ibaraki, Japan,Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Naka-Tokai, Ibaraki, Japan,For correspondence: Tatsuya Joutsuka; Masaki Unno
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24
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Chen H, Dong M, Hu Y, Lin T, Zhang Q, Guo EJ, Gu L, Wu J, Lu Q. Protonation-Induced Colossal Chemical Expansion and Property Tuning in NdNiO 3 Revealed by Proton Concentration Gradient Thin Films. Nano Lett 2022; 22:8983-8990. [PMID: 36331193 DOI: 10.1021/acs.nanolett.2c03229] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Protonation can be used to tune diverse physical and chemical properties of functional oxides. Although protonation of nickelate perovskites has been reported, details on the crystal structure of the protonated phase and a quantitative understanding of the effect of protons on physical properties are still lacking. Therefore, in this work, we select NdNiO3 (NNO) as a model system to understand the protonation process from pristine NNO to protonated HxNdNiO3 (H-NNO). We used a reliable electrochemical method with well-defined reference electrode to trigger the protonation-induced phase transition. We found that the protonated H-NNO phase showed a colossal ∼13% lattice expansion caused by a large tilt of NiO6 octahedra and displacement of Nd cations. Importantly, we further designed a novel device configuration to induce a gradient of proton concentration into a single NNO thin film to establish a quantitative correlation between the proton concentration and the lattice constant and transport property of H-NNO.
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Affiliation(s)
- Haowen Chen
- Zhejiang University, Hangzhou 310027, People's Republic of China
- School of Engineering, Westlake University, Hangzhou 310030, People's Republic of China
| | - Mingdong Dong
- Zhejiang University, Hangzhou 310027, People's Republic of China
- Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou 310030, People's Republic of China
| | - Yang Hu
- School of Engineering, Westlake University, Hangzhou 310030, People's Republic of China
| | - Ting Lin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Er-Jia Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Lin Gu
- Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Jie Wu
- Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou 310030, People's Republic of China
| | - Qiyang Lu
- School of Engineering, Westlake University, Hangzhou 310030, People's Republic of China
- Research Center for Industries of the Future, Westlake University, Hangzhou 310030, Zhejiang, People's Republic of China
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25
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Yi H, Liu J, Yao J, Wang R, Shi W, Lu C. Photoluminescence Mechanism of Carbon Dots: Triggering Multiple Color Emissions through Controlling the Degree of Protonation. Molecules 2022; 27:molecules27196517. [PMID: 36235054 PMCID: PMC9571308 DOI: 10.3390/molecules27196517] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/05/2022]
Abstract
Carbon dots (CDs) have excellent optical properties, low toxicity and easy preparation, which have led to them being widely used in biomedicine, sensing and optical devices. However, although great progress has been made in the preparation of CDs, the detailed exploration of their photoluminescence (PL) mechanism is still under debate due to their complex structures and surface functionalities. Here, we proposed a single change in the pH of the synthesis condition, which had no effect on the CDs intrinsic core states and avoided the mutual influence of multiple PL origins. The m-phenylenediamine (m–PD) served as a carbon source, whose protonation degree determined the surface state of the resulting CDs and the accompanying fluorescence characteristics. The as-obtained CDs materials can be applied in the chemical sensor and anti-counterfeiting fields in a targeted manner. Therefore, our work not only contributes to the explanation of the CDs PL mechanism, but also obtains a series of CDs materials with controllable PL properties.
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26
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Vedernikova AA, Miruschenko MD, Arefina IA, Babaev AA, Stepanidenko EA, Cherevkov SA, Spiridonov IG, Danilov DV, Koroleva AV, Zhizhin EV, Ushakova EV. Dual-Purpose Sensing Nanoprobe Based on Carbon Dots from o-Phenylenediamine: pH and Solvent Polarity Measurement. Nanomaterials (Basel) 2022; 12:nano12193314. [PMID: 36234443 PMCID: PMC9565920 DOI: 10.3390/nano12193314] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/17/2022] [Accepted: 09/20/2022] [Indexed: 05/14/2023]
Abstract
Today, the development of nanomaterials with sensing properties attracts much scientific interest because of the demand for low-cost nontoxic colloidal nanoprobes with high sensitivity and selectivity for various biomedical and environment-related applications. Carbon dots (CDs) are promising candidates for these applications as they demonstrate unique optical properties with intense emissions, biocompatibility, and ease of fabrication. Herein, we developed synthesis protocols to obtain CDs based on o-phenylenediamine with a variety of optical responses depending on additional precursors and changes in the reaction media. The obtained CDs are N-doped (N,S-doped in case of thiourea addition) less than 10 nm spherical particles with emissions observed in the 300−600 nm spectral region depending on their chemical composition. These CDs may act simultaneously as absorptive/fluorescent sensing probes for solvent polarity with ∆S/∆ENT up to 85, for ∆ENT from 0.099 to 1.0 and for pH values in the range of 3.0−8.0, thus opening an opportunity to check the pH in non-pure water or a mixture of solvents. Moreover, CDs preserve their optical properties when embedded in cellulose strips that can be used as sensing probes for fast and easy pH checks. We believe that the resulting dual-purpose sensing nano probes based on CDs will have high demand in various sensing applications.
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Affiliation(s)
- Anna A. Vedernikova
- International Research and Education Centre for Physics of Nanostructures, ITMO University, 197101 Saint Petersburg, Russia
| | - Mikhail D. Miruschenko
- International Research and Education Centre for Physics of Nanostructures, ITMO University, 197101 Saint Petersburg, Russia
| | - Irina A. Arefina
- International Research and Education Centre for Physics of Nanostructures, ITMO University, 197101 Saint Petersburg, Russia
| | - Anton A. Babaev
- International Research and Education Centre for Physics of Nanostructures, ITMO University, 197101 Saint Petersburg, Russia
| | - Evgeniia A. Stepanidenko
- International Research and Education Centre for Physics of Nanostructures, ITMO University, 197101 Saint Petersburg, Russia
| | - Sergei A. Cherevkov
- International Research and Education Centre for Physics of Nanostructures, ITMO University, 197101 Saint Petersburg, Russia
| | - Igor G. Spiridonov
- International Research and Education Centre for Physics of Nanostructures, ITMO University, 197101 Saint Petersburg, Russia
| | - Denis V. Danilov
- Research Park, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | | | - Evgeniy V. Zhizhin
- Research Park, Saint Petersburg State University, 199034 Saint Petersburg, Russia
| | - Elena V. Ushakova
- International Research and Education Centre for Physics of Nanostructures, ITMO University, 197101 Saint Petersburg, Russia
- Correspondence:
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27
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Cathcarth M, Picco AS, Mondo GB, Cardoso MB, Longo GS. Competitive protein adsorption on charge regulating silica-like surfaces: the role of protonation equilibrium. J Phys Condens Matter 2022; 34:364001. [PMID: 35366656 DOI: 10.1088/1361-648x/ac6388] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
We develop a molecular thermodynamic theory to study the interaction of some proteins with a charge regulating silica-like surface under a wide range of conditions, including pH, salt concentration and protein concentration. Proteins are modeled using their three dimensional structure from crystallographic data and the average experimental pKa of amino acid residues. As model systems, we study single-protein and binary solutions of cytochrome c, green fluorescent protein, lysozyme and myoglobin. Our results show that protonation equilibrium plays a critical role in the interactions of proteins with these type of surfaces. The terminal hydroxyl groups on the surface display considerable extent of charge regulation; protein residues with titratable side chains increase protonation according to changes in the local environment and the drop in pH near the surface. This behavior defines protein-surface interactions and leads to the emergence of several phenomena: (i) a complex non-ideal surface charge behavior; (ii) a non-monotonic adsorption of proteins as a function of pH; and (iii) the presence of two spatial regions, a protein-rich and a protein-depleted layer, that occur simultaneously at different distances from the surface when pH is slightly above the isoelectric point of the protein. In binary mixtures, protein adsorption and surface-protein interactions cannot be predicted from single-protein solution considerations.
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Affiliation(s)
- Marilina Cathcarth
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata, Argentina
| | - Agustin S Picco
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata, Argentina
| | - Gabriela B Mondo
- Brazilian Synchrotron (LNLS) and Brazilian Nanotechnology Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
- Institute of Chemistry (IQ), University of Campinas (UNICAMP), Campinas, Brazil
| | - Mateus B Cardoso
- Brazilian Synchrotron (LNLS) and Brazilian Nanotechnology Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
- Institute of Chemistry (IQ), University of Campinas (UNICAMP), Campinas, Brazil
| | - Gabriel S Longo
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata, Argentina
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28
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Schmidt JDR, Beitz E. Mutational Widening of Constrictions in a Formate-Nitrite/H + Transporter Enables Aquaporin-Like Water Permeability and Proton Conductance. J Biol Chem 2021; 298:101513. [PMID: 34929166 PMCID: PMC8749060 DOI: 10.1016/j.jbc.2021.101513] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 10/04/2021] [Revised: 12/14/2021] [Accepted: 12/16/2021] [Indexed: 11/30/2022] Open
Abstract
The unrelated protein families of the microbial formate–nitrite transporters (FNTs) and aquaporins (AQP) likely adapted the same protein fold through convergent evolution. FNTs facilitate weak acid anion/H+ cotransport, whereas AQP water channels strictly exclude charged substrates including protons. The FNT channel–like transduction pathway bears two lipophilic constriction sites that sandwich a highly conserved histidine residue. Because of lacking experiments, the function of these constrictions is unclear, and the protonation status of the central histidine during substrate transport remains a matter of debate. Here, we introduced constriction-widening mutations into the prototypical FNT from Escherichia coli, FocA, and assayed formate/H+ transport properties, water/solute permeability, and proton conductance. We found that enlargement of these constrictions concomitantly decreased formate/formic acid transport. In contrast to wildtype FocA, the mutants were unable to make use of a transmembrane proton gradient as a driving force. A construct in which both constrictions were eliminated exhibited water permeability, similar to AQPs, although accompanied by a proton conductance. Our data indicate that the lipophilic constrictions mainly act as barriers to isolate the central histidine from the aqueous bulk preventing protonation via proton wires. These results are supportive of an FNT transport model in which the central histidine is uncharged, and weak acid substrate anion protonation occurs in the vestibule regions of the transporter before passing the constrictions.
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Affiliation(s)
- Jana D R Schmidt
- Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany
| | - Eric Beitz
- Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-University of Kiel, 24118 Kiel, Germany.
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29
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Omata T, Sharma A, Suzuki I, Ishiyama T, Kohara S, Ohara K, Ono M, Ren Y, Zagarzusem K, Fujioka M, Zhao G, Nishii J. Anhydrous Silicophosphoric Acid Glass: Thermal Properties and Proton Conductivity. Chemphyschem 2021; 23:e202100840. [PMID: 34862847 DOI: 10.1002/cphc.202100840] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Indexed: 11/10/2022]
Abstract
Anhydrous silicophosphoric acid glass with an approximate composition of H5 Si2 P9 O29 was synthesized and its thermal and proton-conducting properties were characterized. Despite exhibiting a glass transition at 192 °C, the supercooled liquid could be handled as a solid up to 280 °C owing to its high viscosity. The glass and its melt exhibited proton conduction with a proton transport number of ∼1. Although covalent O-H bonds were weakened by relatively strong hydrogen bonding, the proton conductivity (4×10-4 S cm-1 at 276 °C) was considerably lower than that of phosphoric acid. The high viscosity of the melt was due to the tight cross-linking of phosphate ion chains by six-fold-coordinated Si atoms. The low proton conductivity was attributed to the trapping of positively charged proton carriers around anionic SiO6 units (expressed as (SiO6/2 )2- ) to compensate for the negative charges.
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Affiliation(s)
- Takahisa Omata
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Aman Sharma
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Issei Suzuki
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Tomohiro Ishiyama
- Research Institute for Energy Conservation, National Institute of Advanced Industrial Science and Technology (AIST), AIST Central 5, Higashi 1-1-1, Tsukuba, Ibaraki, 305-8565, Japan
| | - Shinji Kohara
- Research Center for Advanced Measurement and Characterization, National Institute for Materials Science (NIMS), Sengen, Tsukuba, Ibaraki, 305-0047, Japan
| | - Koji Ohara
- Diffraction and Scattering Division, Japan Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo, 679-5198, Japan
| | - Madoka Ono
- Research Institute for Electronic Science, Hokkaido University, Kita 21 Nishi 10, Kita-ku, Sapporo, 001-0021, Japan
| | - Yang Ren
- School of Materials Sciences and Technology, Xi'an University of Technology, Xi'an, 710048, P. R. China
| | - Khurelbaatar Zagarzusem
- Research Institute for Electronic Science, Hokkaido University, Kita 21 Nishi 10, Kita-ku, Sapporo, 001-0021, Japan
| | - Masaya Fujioka
- Research Institute for Electronic Science, Hokkaido University, Kita 21 Nishi 10, Kita-ku, Sapporo, 001-0021, Japan
| | - Gaoyang Zhao
- School of Materials Sciences and Technology, Xi'an University of Technology, Xi'an, 710048, P. R. China
| | - Junji Nishii
- Research Institute for Electronic Science, Hokkaido University, Kita 21 Nishi 10, Kita-ku, Sapporo, 001-0021, Japan
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30
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Abstract
The kinetic isotope effect (KIE) is key to understanding reaction mechanisms in many areas of chemistry and chemical biology, including organometallic chemistry. This ratio of rate constants, kH /kD , typically falls between 1-7. However, KIEs up to 105 have been reported, and can even be so large that reactivity with deuterium is unobserved. We collect here examples of large KIEs across organometallic chemistry, in catalytic and stoichiometric reactions, along with their mechanistic interpretations. Large KIEs occur in proton transfer reactions such as protonation of organometallic complexes and clusters, protonolysis of metal-carbon bonds, and dihydrogen reactivity. C-H activation reactions with large KIEs occur with late and early transition metals, photogenerated intermediates, and abstraction by metal-oxo complexes. We categorize the mechanistic interpretations of large KIEs into the following three types: (a) proton tunneling, (b) compound effects from multiple steps, and (c) semi-classical effects on a single step. This comprehensive collection of large KIEs in organometallics provides context for future mechanistic interpretation.
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Affiliation(s)
- Phan T Truong
- Department of Chemistry, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97222
| | - Sophia G Miller
- Department of Chemistry, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97222
| | | | - Miriam A Bowring
- Department of Chemistry, Reed College, 3203 SE Woodstock Blvd., Portland, OR 97222
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31
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Abstract
The reactivity of the reduced anthracene complex of scandium [Li(thf)3 ][Sc{N(tBu)Xy}2 (anth)] (2-anth-Li) (Xy=3,5-Me2 C6 H3 ; anth=C14 H10 2- , thf=tetrahydrofuran) toward Brønsted acid [NEt3 H][BPh4 ] and azobenzene is reported. While a stepwise protonation of 2-anth-Li with two equivalents of [NEt3 H][BPh4 ] afforded the scandium cation [Sc{N(tBu)Xy}2 (thf)2 ][BPh4 ] (3), reduction of azobenzene gave a thermolabile, anionic scandium reduced azobenzene complex [Li(thf)][Sc{N(tBu)Xy}2 (η2 -PhNNPh)] (4), which slowly lost one of the anilide ligands to form the neutral scandium azobenzene complex dimer [Sc{N(tBu)Xy}(μ-η2 :η2 -Ph2 N2 )]2 (5). Exposure of 3 to CO2 produced the scandium carbamate complex [Sc{κ2 -O2 CN(tBu)(Xy)}2 ][BPh4 ] (6) as a result of CO2 insertion into the Sc-N bonds. In an attempt to prepare scandium hydrides, the reaction of 3 with the hydride sources LiAlH4 and Na[BEt3 H] led to the terminal aluminum hydride [AlH{N(tBu)Xy}2 (thf)] (7) and the scandium n-butoxide [Sc{N(tBu)(Xy)}2 (μ-OnBu)] (8) after Sc/Al transmetalation and nucleophilic ring-opening of THF, respectively. All reported compounds isolated in moderate to good yields were fully characterized.
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Affiliation(s)
- Priyabrata Ghana
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Thomas P. Spaniol
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
| | - Jun Okuda
- Institute of Inorganic ChemistryRWTH Aachen UniversityLandoltweg 152056AachenGermany
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32
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Schröder GC, Meilleur F. Metalloprotein catalysis: structural and mechanistic insights into oxidoreductases from neutron protein crystallography. Acta Crystallogr D Struct Biol 2021; 77:1251-1269. [PMID: 34605429 PMCID: PMC8489226 DOI: 10.1107/s2059798321009025] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/31/2021] [Indexed: 11/11/2022] Open
Abstract
Metalloproteins catalyze a range of reactions, with enhanced chemical functionality due to their metal cofactor. The reaction mechanisms of metalloproteins have been experimentally characterized by spectroscopy, macromolecular crystallography and cryo-electron microscopy. An important caveat in structural studies of metalloproteins remains the artefacts that can be introduced by radiation damage. Photoreduction, radiolysis and ionization deriving from the electromagnetic beam used to probe the structure complicate structural and mechanistic interpretation. Neutron protein diffraction remains the only structural probe that leaves protein samples devoid of radiation damage, even when data are collected at room temperature. Additionally, neutron protein crystallography provides information on the positions of light atoms such as hydrogen and deuterium, allowing the characterization of protonation states and hydrogen-bonding networks. Neutron protein crystallography has further been used in conjunction with experimental and computational techniques to gain insight into the structures and reaction mechanisms of several transition-state metal oxidoreductases with iron, copper and manganese cofactors. Here, the contribution of neutron protein crystallography towards elucidating the reaction mechanism of metalloproteins is reviewed.
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Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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33
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Jeong HJ, Park C, Jeon H, Lee KN, Lee J, Lim SC, Namkoong G, Jeong MS. Quasi-2D Halide Perovskite Memory Device Formed by Acid-Base Binary Ligand Solution Composed of Oleylamine and Oleic Acid. ACS Appl Mater Interfaces 2021; 13:40891-40900. [PMID: 34470107 DOI: 10.1021/acsami.1c09725] [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] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Organometal halide perovskite materials are receiving significant attention for the fabrication of resistive-switching memory devices based on their high stability, low power consumption, rapid switching, and high ON/OFF ratios. In this study, we synthesized 3D FAPbBr3 and quasi-2D (RNH3)2(FA)1Pb2Br7 films using an acid-base binary ligand solution composed of oleylamine (OlAm) and oleic acid in toluene. The quasi-2D (RNH3)2(FA)1Pb2Br7 films were synthesized by controlling the protonated OlAm (RNH3+) solution concentration to replace FA+ cations with large organic RNH3+ cations from 3D FAPbBr3 perovskites. The quasi-2D (RNH3)2(FA)1Pb2Br7 devices exhibited nonvolatile write-once read-many (WORM) memory characteristics, whereas the 3D FAPbBr3 only exhibited hysteresis behavior. Analysis of the 3D FAPbBr3 device indicated operation in the trap-limited space-charge-limited current region. In contrast, quasi-2D (RNH3)2(FA)1Pb2Br7 devices provide low trap density that is completely filled by injected charge carriers and then subsequently form conductive filaments (CFs) to operate as WORM devices. Nanoscale morphology analysis and an associated current mapping study based on conductive atomic force microscopy measurements revealed that perovskite grain boundaries serve as major channels for high current, which may be correlated with the conductive low-resistive-switching behavior and formation of CFs in WORM devices.
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Affiliation(s)
- Hyeon Jun Jeong
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Chulho Park
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hobeom Jeon
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Kang-Nyeoung Lee
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Juchan Lee
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Seong Chu Lim
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Gon Namkoong
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Electrical and Computer Engineering, Old Dominion University, Applied Research Centre, 12050 Jefferson Avenue, Newport News, Virginia 23606, United States
| | - Mun Seok Jeong
- Department of Physics and Department of Energy Engineering, Hanyang University, Seoul 04763, Republic of Korea
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34
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Zhu Q, Png ZM, Lin T, Loh XJ, Tang T, Xu J. Synthesis and Halochromic Properties of 1,2,6-Tri- and 1,2,3,6-Tetra-aryl Azulenes. Chempluschem 2021; 86:1116-1122. [PMID: 34402212 DOI: 10.1002/cplu.202100261] [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: 06/07/2021] [Revised: 07/22/2021] [Indexed: 11/06/2022]
Abstract
A series of novel 2,6-functionalized azulene molecules Azu1-3 with varied fluorene substituents at the 1- and 3-positions of azulene as well as at the 5'-position of 2-thiophene group were synthesized. Their electronic absorption and emission spectra at neutral and protonated states were examined. It was found that after functionalization with fluorenyl groups, Azu1-3 exhibited absorption maxima at 445, 451 to 468 nm, respectively. In contrast, their corresponding protonated species showed much redshifted absorption maxima at 560, 582 to 643 nm, respectively, mainly due to the extension of conjugation length and the large dipole moment along the C2v axis of 2,6-substituted azulene molecules. Azu1-3 are non-fluorescent in their neutral forms, but became emissive in their protonated states. Analysis of absorption and emission spectra shows that substitution of the 1- or 3-position of azulene led to decrease in response to trifluoroacetic acid.
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Affiliation(s)
- Qiang Zhu
- Institute of Materials Research and Engineering, The Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Zhuang Mao Png
- Institute of Materials Research and Engineering, The Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Tingting Lin
- Institute of Materials Research and Engineering, The Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Xian Jun Loh
- Institute of Materials Research and Engineering, The Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Tao Tang
- Institute of Materials Research and Engineering, The Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Jianwei Xu
- Institute of Materials Research and Engineering, The Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore, 138634, Singapore.,Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
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Merk V, Speiser E, Werncke W, Esser N, Kneipp J. pH-Dependent Flavin Adenine Dinucleotide and Nicotinamide Adenine Dinucleotide Ultraviolet Resonance Raman (UVRR) Spectra at Intracellular Concentration. Appl Spectrosc 2021; 75:994-1002. [PMID: 34076541 PMCID: PMC8320563 DOI: 10.1177/00037028211025575] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The ultraviolet resonance Raman spectra of the adenine-containing enzymatic redox cofactors nicotinamide adenine dinucleotide and flavin adenine dinucleotide in aqueous solution of physiological concentration are compared with the aim of distinguishing between them and their building block adenine in potential co-occurrence in biological materials. At an excitation wavelength of 266 nm, the spectra are dominated by the strong resonant contribution from adenine; nevertheless, bands assigned to vibrational modes of the nicotinamide and the flavin unit are found to appear at similar signal strength. Comparison of spectra measured at pH 7 with data obtained pH 10 and pH 3 shows characteristic changes when pH is increased or lowered, mainly due to deprotonation of the flavin and nicotinamide moieties, and protonation of the adenine, respectively.
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Affiliation(s)
- Virginia Merk
- Department of Chemistry and School of Analytical Sciences Adlershof, Humboldt-Universität zu Berlin, Berlin, Germany
- ISAS Berlin, Berlin, Germany
| | - Eugen Speiser
- ISAS Berlin, Berlin, Germany
- Department of Physics, Institute of Solid State Physics, Technical University Berlin, Berlin, Germany
| | | | - Norbert Esser
- ISAS Berlin, Berlin, Germany
- Department of Physics, Institute of Solid State Physics, Technical University Berlin, Berlin, Germany
| | - Janina Kneipp
- Department of Chemistry and School of Analytical Sciences Adlershof, Humboldt-Universität zu Berlin, Berlin, Germany
- Janina Kneipp, Humboldt-Universitat zu Berlin, Brook-Taylor-Str. 2, Berlin 12489, Germany.
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36
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Yang J, Acharjya A, Ye MY, Rabeah J, Li S, Kochovski Z, Youk S, Roeser J, Grüneberg J, Penschke C, Schwarze M, Wang T, Lu Y, van de Krol R, Oschatz M, Schomäcker R, Saalfrank P, Thomas A. Protonated Imine-Linked Covalent Organic Frameworks for Photocatalytic Hydrogen Evolution. Angew Chem Int Ed Engl 2021; 60:19797-19803. [PMID: 34043858 PMCID: PMC8457210 DOI: 10.1002/anie.202104870] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [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: 04/08/2021] [Revised: 05/21/2021] [Indexed: 11/30/2022]
Abstract
Covalent organic frameworks (COFs) have emerged as an important class of organic semiconductors and photocatalysts for the hydrogen evolution reaction (HER)from water. To optimize their photocatalytic activity, typically the organic moieties constituting the frameworks are considered and the most suitable combinations of them are searched for. However, the effect of the covalent linkage between these moieties on the photocatalytic performance has rarely been studied. Herein, we demonstrate that donor‐acceptor (D‐A) type imine‐linked COFs can produce hydrogen with a rate as high as 20.7 mmol g−1 h−1 under visible light irradiation, upon protonation of their imine linkages. A significant red‐shift in light absorbance, largely improved charge separation efficiency, and an increase in hydrophilicity triggered by protonation of the Schiff‐base moieties in the imine‐linked COFs, are responsible for the improved photocatalytic performance.
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Affiliation(s)
- Jin Yang
- Department of Chemistry/, Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623, Berlin, Germany
| | - Amitava Acharjya
- Department of Chemistry/, Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623, Berlin, Germany
| | - Meng-Yang Ye
- Department of Chemistry/, Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623, Berlin, Germany
| | - Jabor Rabeah
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Str. 29a, 18059, Rostock, Germany
| | - Shuang Li
- Department of Chemistry/, Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623, Berlin, Germany
| | - Zdravko Kochovski
- Institute of Electrochemical Energy Storage, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Sol Youk
- Department of Colloid Chemistry, Max-Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Jérôme Roeser
- Department of Chemistry/, Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623, Berlin, Germany
| | - Julia Grüneberg
- Department of Chemistry/, Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623, Berlin, Germany
| | - Christopher Penschke
- Theoretical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Michael Schwarze
- Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany
| | - Tianyi Wang
- Institute for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Yan Lu
- Institute of Electrochemical Energy Storage, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Roel van de Krol
- Institute for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109, Berlin, Germany
| | - Martin Oschatz
- Department of Colloid Chemistry, Max-Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Reinhard Schomäcker
- Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany
| | - Peter Saalfrank
- Theoretical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Arne Thomas
- Department of Chemistry/, Functional Materials, Technische Universität Berlin, Hardenbergstraße 40, 10623, Berlin, Germany
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37
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Willow SY, Yuan M, Juárez O, Minh DDL. Electrostatics and water occlusion regulate covalently-bound flavin mononucleotide cofactors of Vibrio cholerae respiratory complex NQR. Proteins 2021; 89:1376-1385. [PMID: 34091964 DOI: 10.1002/prot.26158] [Citation(s) in RCA: 3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/20/2021] [Accepted: 06/01/2021] [Indexed: 12/20/2022]
Abstract
Proteins like NADH:ubiquinone oxidoreductase (NQR), an essential enzyme and ion pump in the physiology of several pathogenic bacteria, tightly regulate the redox properties of their cofactors. Although flavin mononucleotide (FMN) is fully reduced in aqueous solution, FMN in subunits B and C of NQR exclusively undergo one-electron transitions during its catalytic cycle. Here, we perform ab initio calculations and molecular dynamics simulations to elucidate the mechanisms that regulate the redox state of FMN in NQR. QM/MM calculations show that binding site electrostatics disfavor anionic forms of FMNH2 , but permit a neutral form of the fully reduced flavin. The potential energy surface is unaffected by covalent bonding between FMN and threonine. Molecular dynamics simulations show that the FMN binding sites are inaccessible by water, suggesting that further reductions of the cofactors are limited or prohibited by the availability of water and other proton donors. These findings provide a deeper understanding of the mechanisms used by NQR to regulate electron transfer through the cofactors and perform its physiologic role. They also provide the first, to our knowledge, evidence of the simple concept that proteins regulate flavin redox states via water occlusion.
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Affiliation(s)
- Soohaeng Yoo Willow
- Department of Chemistry, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Ming Yuan
- Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois, USA
| | - Oscar Juárez
- Department of Biological Sciences, Illinois Institute of Technology, Chicago, Illinois, USA
| | - David D L Minh
- Department of Chemistry, Illinois Institute of Technology, Chicago, Illinois, USA
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38
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Köteles I, Mazák K, Tóth G, Horváth P, Kiss E, Tűz B, Hosztafi S. Synthesis of 3-O-Carboxyalkyl Morphine Derivatives and Characterization of Their Acid-Base Properties. Chem Biodivers 2021; 18:e2100135. [PMID: 34018677 DOI: 10.1002/cbdv.202100135] [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: 02/23/2021] [Accepted: 05/18/2021] [Indexed: 11/11/2022]
Abstract
The C-3 phenolic hydroxy group containing morphine derivatives (morphine, oxymorphone, naloxone, naltrexone) are excellent candidates for the synthesis of 3-O-functionalized molecules. Achieving free carboxylic group containing derivatives gives the opportunity for further modification and conjugation that could be used for immunization and immunoassays. For this purpose ethyl bromo- and chloroacetate can be used as O-alkylating agents. Hydrolyzing the products affords the appropriate free carboxylic group containing 3-O-carboxyalkyl derivatives. As these molecules contain an acidic and a basic functional group the protonation macro- and microconstants were determined too, using pH-potentiometry and NMR-pH titration, beside fully characterizing their structure using IR, CD, NMR and HR-MS measurements.
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Affiliation(s)
- István Köteles
- Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre u. 9., H-1092, Budapest, Hungary
| | - Károly Mazák
- Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre u. 9., H-1092, Budapest, Hungary
| | - Gergő Tóth
- Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre u. 9., H-1092, Budapest, Hungary
| | - Péter Horváth
- Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre u. 9., H-1092, Budapest, Hungary
| | - Eszter Kiss
- Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre u. 9., H-1092, Budapest, Hungary
| | - Boglárka Tűz
- Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre u. 9., H-1092, Budapest, Hungary
| | - Sándor Hosztafi
- Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre u. 9., H-1092, Budapest, Hungary
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Shin Y, Husni P, Kang K, Lee D, Lee S, Lee E, Youn Y, Oh K. Recent Advances in pH- or/and Photo-Responsive Nanovehicles. Pharmaceutics 2021; 13:725. [PMID: 34069233 PMCID: PMC8157172 DOI: 10.3390/pharmaceutics13050725] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 01/10/2023] Open
Abstract
The combination of nanotechnology and chemotherapy has resulted in more effective drug design via the development of nanomaterial-based drug delivery systems (DDSs) for tumor targeting. Stimulus-responsive DDSs in response to internal or external signals can offer precisely controlled delivery of preloaded therapeutics. Among the various DDSs, the photo-triggered system improves the efficacy and safety of treatment through spatiotemporal manipulation of light. Additionally, pH-induced delivery is one of the most widely studied strategies for targeting the acidic micro-environment of solid tumors. Accordingly, in this review, we discuss representative strategies for designing DDSs using light as an exogenous signal or pH as an endogenous trigger.
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Affiliation(s)
- Yuseon Shin
- Department of Global Innovative Drugs, The Graduate School of Chung-Ang University and College of Pharmacy, Chung-Ang University, 221 Heukseok-dong, Seoul 06974, Korea; (Y.S.); (P.H.); (K.K.); (D.L.); (S.L.)
| | - Patihul Husni
- Department of Global Innovative Drugs, The Graduate School of Chung-Ang University and College of Pharmacy, Chung-Ang University, 221 Heukseok-dong, Seoul 06974, Korea; (Y.S.); (P.H.); (K.K.); (D.L.); (S.L.)
| | - Kioh Kang
- Department of Global Innovative Drugs, The Graduate School of Chung-Ang University and College of Pharmacy, Chung-Ang University, 221 Heukseok-dong, Seoul 06974, Korea; (Y.S.); (P.H.); (K.K.); (D.L.); (S.L.)
| | - Dayoon Lee
- Department of Global Innovative Drugs, The Graduate School of Chung-Ang University and College of Pharmacy, Chung-Ang University, 221 Heukseok-dong, Seoul 06974, Korea; (Y.S.); (P.H.); (K.K.); (D.L.); (S.L.)
| | - Sehwa Lee
- Department of Global Innovative Drugs, The Graduate School of Chung-Ang University and College of Pharmacy, Chung-Ang University, 221 Heukseok-dong, Seoul 06974, Korea; (Y.S.); (P.H.); (K.K.); (D.L.); (S.L.)
| | - Eunseong Lee
- Division of Biotechnology, The Catholic University of Korea, Bucheon 14662, Korea;
| | - Yuseok Youn
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, Korea;
| | - Kyungtaek Oh
- Department of Global Innovative Drugs, The Graduate School of Chung-Ang University and College of Pharmacy, Chung-Ang University, 221 Heukseok-dong, Seoul 06974, Korea; (Y.S.); (P.H.); (K.K.); (D.L.); (S.L.)
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40
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Kim M, Bezprozvanny I. Differences in Recycling of Apolipoprotein E3 and E4-LDL Receptor Complexes-A Mechanistic Hypothesis. Int J Mol Sci 2021; 22:5030. [PMID: 34068576 DOI: 10.3390/ijms22095030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/05/2021] [Accepted: 05/07/2021] [Indexed: 12/13/2022] Open
Abstract
Apolipoprotein E (ApoE) is a protein that plays an important role in the transport of fatty acids and cholesterol and in cellular signaling. On the surface of the cells, ApoE lipoparticles bind to low density lipoprotein receptors (LDLR) that mediate the uptake of the lipids and downstream signaling events. There are three alleles of the human ApoE gene. Presence of ApoE4 allele is a major risk factor for developing Alzheimer’s disease (AD) and other disorders late in life, but the mechanisms responsible for biological differences between different ApoE isoforms are not well understood. We here propose that the differences between ApoE isoforms can be explained by differences in the pH-dependence of the association between ApoE3 and ApoE4 isoforms and LDL-A repeats of LDLR. As a result, the following endocytosis ApoE3-associated LDLRs are recycled back to the plasma membrane but ApoE4-containing LDLR complexes are trapped in late endosomes and targeted for degradation. The proposed mechanism is predicted to lead to a reduction in steady-state surface levels of LDLRs and impaired cellular signaling in ApoE4-expressing cells. We hope that this proposal will stimulate experimental research in this direction that allows the testing of our hypothesis.
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Abstract
Marine bacterial TAT rhodopsin possesses the pKa of the retinal Schiff base, the chromophore, at neutral pH, and photoexcitation of the visible protonated state forms the isomerized 13-cis state, but reverts to the original state within 10–5 sec. To understand the origin of these unique molecular properties of TAT rhodopsin, we mutated Thr82 into Asp, because many microbial rhodopsins contain Asp at the corresponding position as the Schiff base counterion. A pH titration study revealed that the pKa of the Schiff base increased considerably in T82D (>10.5), and that the pKa of the counterion, which is likely to be D82, is 8.1. It was thus concluded that T82 is the origin of the neutral pKa of the Schiff base in TAT rhodopsin. The photocycle of T82D TAT rhodopsin exhibited strong pH dependence. When pH is lower than the pKa of the counterion (pH <8.1), formation of the primary K intermediate was observed by low-temperature UV-visible spectroscopy, but flash photolysis failed to monitor photointermdiates at >10–5 sec. The results were identical for the wild-type TAT rhodopsin. In contrast, when pH was higher than the pKa of the counterion, we observed the formation of the M intermediate, which decayed with the time constants of 3.75 ms and 12.2 sec. It is likely that the protonation state of D82 dramatically switches the photoreaction dynamics of T82D, whose duration lies between <10–5 sec and >10 sec. It was thus concluded that T82 is one of the determinants of the unique photochemistry of TAT rhodopsin.
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Affiliation(s)
- Teppei Sugimoto
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Kota Katayama
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan.,OptoBioTechnology Research Center, Nagoya Institute of Technology, Nagoya, Aichi 466-8555, Japan
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42
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Dylong A, Dysz K, Bogdanowicz KA, Przybył W, Konieczny KA, Turowska-Tyrk I, Kaim A, Iwan A. Crystal Structure Determination of 4-[(Di-p-tolyl-amino)-benzylidene]-(5-pyridin-4-yl-[1,3,4]thiadiazol-2-yl)-imine along with Selected Properties of Imine in Neutral and Protonated Form with Camforosulphonic Acid: Theoretical and Experimental Studies. Materials (Basel) 2021; 14:1952. [PMID: 33924588 PMCID: PMC8070542 DOI: 10.3390/ma14081952] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 11/17/2022]
Abstract
The crystal structure was determined for the first time for 4-[(di-p-tolyl-amino)benzylidene]-(5-pyridin-4-yl-[1,3,4]thiadiazol-2-yl)-imine (trans-PPL9) by X-ray diffraction. The imine crystallized in the monoclinic P21/n space group with a = 18.9567(7) Å, b = 6.18597(17) Å, c = 22.5897(7) Å, and β = 114.009(4)°. Intermolecular interactions in the PPL9 crystal were only weak C-H⋯N hydrogen bonds investigated using the Hirshfeld surface. The electronic and geometric structure of the imine were investigated by the density functional theory and the time-dependent density-functional theory. The properties of the imine in neutral and protonated form with camforosulphonic acid (CSA) were investigated using cyclic voltammetry, UV-vis and 1H NMR spectroscopy. Theoretical and experimental studies showed that for the 1:1 molar ratio the protonation occured on nitrogen in pyridine in the PPL9 structure, as an effect of Brönsted acid-base interactions. Thermographic camera was used to defined defects in constructed simple devices with ITO/PPL9 (or PPL9:CSA)/Ag/ITO architecture. In conclusion, a thermally stable imine was synthesized in crystalline form and by CSA doping, a modification of absorption spectra together with reduction of overheating process was observed, suggesting its potential application in optoelectronics.
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Affiliation(s)
- Agnieszka Dylong
- Military Institute of Engineer Technology, 136 Obornicka Str., 50-961 Wroclaw, Poland; (A.D.); (K.D.); (K.A.B.); (W.P.)
| | - Karolina Dysz
- Military Institute of Engineer Technology, 136 Obornicka Str., 50-961 Wroclaw, Poland; (A.D.); (K.D.); (K.A.B.); (W.P.)
| | - Krzysztof A. Bogdanowicz
- Military Institute of Engineer Technology, 136 Obornicka Str., 50-961 Wroclaw, Poland; (A.D.); (K.D.); (K.A.B.); (W.P.)
| | - Wojciech Przybył
- Military Institute of Engineer Technology, 136 Obornicka Str., 50-961 Wroclaw, Poland; (A.D.); (K.D.); (K.A.B.); (W.P.)
| | - Krzysztof A. Konieczny
- Faculty of Chemistry, Wrocław University of Science and Technology, 27 Wybrzeże Wyspiańskiego, 50-370 Wroclaw, Poland; (K.A.K.); (I.T.-T.)
| | - Ilona Turowska-Tyrk
- Faculty of Chemistry, Wrocław University of Science and Technology, 27 Wybrzeże Wyspiańskiego, 50-370 Wroclaw, Poland; (K.A.K.); (I.T.-T.)
| | - Andrzej Kaim
- Faculty of Chemistry, University of Warsaw, 1 Pasteura Str., 02-093 Warsaw, Poland;
| | - Agnieszka Iwan
- Military Institute of Engineer Technology, 136 Obornicka Str., 50-961 Wroclaw, Poland; (A.D.); (K.D.); (K.A.B.); (W.P.)
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Schröder GC, O’Dell WB, Swartz PD, Meilleur F. Preliminary results of neutron and X-ray diffraction data collection on a lytic polysaccharide monooxygenase under reduced and acidic conditions. Acta Crystallogr F Struct Biol Commun 2021; 77:128-133. [PMID: 33830078 PMCID: PMC8034432 DOI: 10.1107/s2053230x21002399] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/02/2021] [Indexed: 11/10/2022] Open
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are copper-center enzymes that are involved in the oxidative cleavage of the glycosidic bond in crystalline cellulose and other polysaccharides. The LPMO reaction is initiated by the addition of a reductant and oxygen to ultimately form an unknown activated copper-oxygen species that is responsible for polysaccharide-substrate H-atom abstraction. Given the sensitivity of metalloproteins to radiation damage, neutron protein crystallography provides a nondestructive technique for structural characterization while also informing on the positions of H atoms. Neutron cryo-crystallography permits the trapping of catalytic intermediates, thereby providing insight into the protonation states and chemical nature of otherwise short-lived species in the reaction mechanism. To characterize the reaction-mechanism intermediates of LPMO9D from Neurospora crassa, a cryo-neutron diffraction data set was collected from an ascorbate-reduced crystal. A second neutron diffraction data set was collected at room temperature from an LPMO9D crystal exposed to low-pH conditions to probe the protonation states of ionizable groups involved in catalysis under acidic conditions.
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Affiliation(s)
- Gabriela C. Schröder
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - William B. O’Dell
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Paul D. Swartz
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Flora Meilleur
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, NC 27695, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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Ng BJ, Musyaffa MK, Er CC, Packiam KAR, Lee WPC, Tan LL, Lee HW, Ooi CW, Chai SP. Proton-Functionalized Graphitic Carbon Nitride for Efficient Metal-Free Destruction of Escherichia coli under Low-Power Light Irradiation. Chemistry 2021; 27:3085-3090. [PMID: 33263935 DOI: 10.1002/chem.202004238] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 09/17/2020] [Indexed: 11/08/2022]
Abstract
Universal access to clean water has been a global ambition over the years. Photocatalytic water disinfection through advanced oxidation processes has been regarded as one of the promising methods for breaking down microbials. The forefront of this research focuses on the application of metal-free photocatalysts for disinfection to prevent secondary pollution. Graphitic carbon nitride (g-C3 N4 ) has achieved instant attention as a metal-free and visible-light-responsive photocatalyst for various energy and environmental applications. However, the photocatalytic efficiency of g-C3 N4 is still affected by its rapid charge recombination and sluggish electron-transfer kinetics. In this contribution, two-dimensionally protonated g-C3 N4 was employed as metal-free photocatalyst for water treatment and demonstrated 100 % of Escherichia coli within 4 h under irradiation with a 23 W light bulb. The introduction of protonation can modulate the surface charge of g-C3 N4 ; this enhances its conductivity and provides a "highway" for the delocalization of electrons. This work highlights the potential of conjugated polymers in antibacterial application.
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Affiliation(s)
- Boon-Junn Ng
- Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Muhammad Khosyi Musyaffa
- Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Chen-Chen Er
- Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Kulandai Arockia Rajesh Packiam
- Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - W P Cathie Lee
- Entropic Interface Group, Engineering Product Development, Singapore University of Technology and Design, 487372, Singapore, Singapore
| | - Lling-Lling Tan
- Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Hing Wah Lee
- Nanoelectronics Lab, Mimos Berhad, Technology Park Malaysia, Kuala Lumpur, 57000, Malaysia
| | - Chien Wei Ooi
- Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Siang-Piao Chai
- Multidisciplinary Platform of Advanced Engineering, Chemical Engineering Discipline, School of Engineering, Monash University, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
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45
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Abstract
Electrophilic functionalisation of [Cp*Fe(η5 -P5 )] (1) yields the first transition-metal complexes of pentaphospholes (cyclo-P5 R). Silylation of 1 with [(Et3 Si)2 (μ-H)][B(C6 F5 )4 ] leads to the ionic species [Cp*Fe(η5 -P5 SiEt3 )][B(C6 F5 )4 ] (2), whose subsequent reaction with H2 O yields the parent compound [Cp*Fe(η5 -P5 H)][B(C6 F5 )4 ] (3). The synthesis of a carbon-substituted derivative [Cp*Fe(η5 -P5 Me)][X] ([X]- =[FB(C6 F5 )3 ]- (4 a), [B(C6 F5 )4 ]- (4 b)) is achieved by methylation of 1 employing [Me3 O][BF4 ] and B(C6 F5 )3 or a combination of MeOTf and [Li(OEt2 )2 ][B(C6 F5 )4 ]. The structural characterisation of these compounds reveals a slight envelope structure for the cyclo-P5 R ligand. Detailed NMR-spectroscopic studies suggest a highly dynamic behaviour and thus a distinct lability for 2 and 3 in solution. DFT calculations shed light on the electronic structure and bonding situation of this unprecedented class of compounds.
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Affiliation(s)
- Christoph Riesinger
- Institute of Inorganic ChemistryUniversity of Regensburg93040RegensburgGermany
| | - Gábor Balázs
- Institute of Inorganic ChemistryUniversity of Regensburg93040RegensburgGermany
| | | | - Manfred Scheer
- Institute of Inorganic ChemistryUniversity of Regensburg93040RegensburgGermany
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Chang X, Zhang J, Zhang Q, Guo C. Merging Electrosynthesis and Bifunctional Squaramide Catalysis in the Asymmetric Detrifluoroacetylative Alkylation Reactions. Angew Chem Int Ed Engl 2020; 59:18500-18504. [PMID: 32652737 DOI: 10.1002/anie.202006903] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [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: 05/13/2020] [Revised: 07/07/2020] [Indexed: 11/07/2022]
Abstract
An enantioselective bifunctional squaramide-catalyzed detrifluoroacetylative alkylation reaction has been developed under electrochemical conditions. The unified strategy based on this key tandem methodology has been divergently explored for the asymmetric synthesis of fluorine-containing target molecules with good stereocontrol (up to 95 % ee). Furthermore, this asymmetric catalytic reaction combines the benefits of electrosynthesis and organocatalysis for the preparation of biologically relevant products containing C-F tertiary stereogenic centers.
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Affiliation(s)
- Xihao Chang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Jiayin Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Qinglin Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
| | - Chang Guo
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, China
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47
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Valadbeigi Y, Ilbeigi V, Mirsharifi MS. Mechanism of atmospheric pressure chemical ionization of morphine, codeine, and thebaine in corona discharge-ion mobility spectrometry: Protonation, ammonium attachment, and carbocation formation. J Mass Spectrom 2020; 55:e4586. [PMID: 32720743 DOI: 10.1002/jms.4586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/30/2020] [Accepted: 06/05/2020] [Indexed: 06/11/2023]
Abstract
Atmospheric pressure chemical ionizations (APCIs) of morphine, codeine, and thebaine were studied in a corona discharge ion source using ion mobility spectrometry (IMS) at temperature range of 100°C-200°C. Density functional theory (DFT) at the B3LYP/6-311++G(d,p) and M062X/6-311++G(d,p) levels of theory were used to interpret the experimental data. It was found that in the presence of H3 O+ as reactant ion (RI), ionization of morphine and codeine proceeds via both the protonation and carbocation formation, whereas thebaine participates only in protonation. Carbocation formation (fragmentation) was diminished with decrease in the temperature. At lower temperatures, proton-bound dimers of the compounds were also formed. Ammonia was used as a dopant to produce NH4 + as an alternative RI. In the presence of NH4 + , proton transfer from ammonium ion to morphine, codeine, and thebaine was the dominant mechanism of ionization. However, small amount of ammonium attachment was also observed. The theoretical calculations showed that nitrogen atom of the molecules is the most favorable proton acceptor site while the oxygen atoms participate in ammonium attachment. Furthermore, formation of the carbocations is because of the water elimination from the protonated forms of morphine and codeine.
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Affiliation(s)
- Younes Valadbeigi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
| | - Vahideh Ilbeigi
- TOF Tech. Pars Company, Isfahan Science & Technology Town, Isfahan, Iran
| | - Maryam S Mirsharifi
- Department of Chemistry, Faculty of Science, Imam Khomeini International University, Qazvin, Iran
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48
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Zeng Q, Guo S, Sun Y, Li Z, Feng W. Protonation-Induced Enhanced Optical-Light Photochromic Properties of an Inorganic-Organic Phosphomolybdic Acid/Polyaniline Hybrid Thin Film. Nanomaterials (Basel) 2020; 10:E1839. [PMID: 32942574 DOI: 10.3390/nano10091839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/07/2020] [Accepted: 09/12/2020] [Indexed: 11/16/2022]
Abstract
A phosphomolybdic acid/polyaniline (PMoA/PANI) optical-light photochromic inorganic/organic hybrid thin film was successfully synthesized by protonation between the the multiprotonic acid phosphomolybdic acid (H3PO4·12MoO3) and the conductive polymer polyaniline. The stable Keggin-type structure of PMoA was maintained throughout the process. Protonation and proton transfer successfully transformed the quinone structure of eigenstate PANI into the benzene structure of single-polarized PANI in the PMoA/PANI hybridized thin film, and proton transfer transformed the benzene structure of single-polarized PANI back to the quinone structure of eigenstate PANI in the PMoA/PANI hybrid thin film, as verified by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The average distribution of PMoA/PANI was observed by atom force microscopy (AFM). Interestingly, protonation of PMoA caused PANI to trigger transformation of the quinone structure into the single-polarized benzene structure, which enhanced the electron delocalization ability and vastly enhanced the maximum light absorption of the PMoA/PANI hybrid thin film as confirmed by density functional theory (DFT), electrochemistry, and ultraviolet-visible spectroscopy (UV-Vis) studies. Under optical-light illumination, the pale-yellow PMoA/PANI hybrid thin film gradually turned deep blue, thus demonstrating a photochromic response, and reversible photochromism was also observed in the presence of hydrogen peroxide (H2O2) or oxygen (O2). After 40 min of optical-light illumination, 36% of the Mo5+ species in PMoA was photoreduced via a protonation-induced proton transfer mechanism, and this proton transfer resulted in a structural change of PANI, as observed by XPS, generating a dominant structure with high maximum light absorption of 3.46, when compared with the literature reports.
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49
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Pethő Z, Najder K, Carvalho T, McMorrow R, Todesca LM, Rugi M, Bulk E, Chan A, Löwik CWGM, Reshkin SJ, Schwab A. pH-Channeling in Cancer: How pH-Dependence of Cation Channels Shapes Cancer Pathophysiology. Cancers (Basel) 2020; 12:E2484. [PMID: 32887220 PMCID: PMC7565548 DOI: 10.3390/cancers12092484] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/20/2022] Open
Abstract
Tissue acidosis plays a pivotal role in tumor progression: in particular, interstitial acidosis promotes tumor cell invasion, and is a major contributor to the dysregulation of tumor immunity and tumor stromal cells. The cell membrane and integral membrane proteins commonly act as important sensors and transducers of altered pH. Cell adhesion molecules and cation channels are prominent membrane proteins, the majority of which is regulated by protons. The pathophysiological consequences of proton-sensitive ion channel function in cancer, however, are scarcely considered in the literature. Thus, the main focus of this review is to highlight possible events in tumor progression and tumor immunity where the pH sensitivity of cation channels could be of great importance.
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Affiliation(s)
- Zoltán Pethő
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Karolina Najder
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Tiago Carvalho
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 90126 Bari, Italy; (T.C.); (S.J.R.)
| | - Roisin McMorrow
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, 3035 GD Rotterdam, The Netherlands; (R.M.); (C.W.G.M.L.)
| | - Luca Matteo Todesca
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Micol Rugi
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Etmar Bulk
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Alan Chan
- Percuros B.V., 2333 CL Leiden, The Netherlands;
| | - Clemens W. G. M. Löwik
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, 3035 GD Rotterdam, The Netherlands; (R.M.); (C.W.G.M.L.)
- Department of Oncology CHUV, UNIL and Ludwig Cancer Center, 1011 Lausanne, Switzerland
| | - Stephan J. Reshkin
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 90126 Bari, Italy; (T.C.); (S.J.R.)
| | - Albrecht Schwab
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
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50
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Liu Y, White KA, Barber DL. Intracellular pH Regulates Cancer and Stem Cell Behaviors: A Protein Dynamics Perspective. Front Oncol 2020; 10:1401. [PMID: 32983969 PMCID: PMC7479815 DOI: 10.3389/fonc.2020.01401] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [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: 05/12/2020] [Accepted: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
The International Society of Cancer Metabolism (ISCaM) meeting on Cancer Metabolic Rewiring, held in Braga Portugal in October 2019, provided an outstanding forum for investigators to present current findings and views, and discuss ideas and future directions on fundamental biology as well as clinical translations. The first session on Cancer pH Dynamics was preceded by the opening keynote presentation from our group entitled Intracellular pH Regulation of Protein Dynamics: From Cancer to Stem Cell Behaviors. In this review we introduce a brief background on intracellular pH (pHi) dynamics, including how it is regulated as well as functional consequences, summarize key findings included in our presentation, and conclude with perspectives on how understanding the role of pHi dynamics in stem cells can be relevant for understanding how pHi dynamics enables cancer progression.
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Affiliation(s)
- Yi Liu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States
| | - Katharine A White
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, United States
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