1
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Wehrhan L, Keller BG. Prebound State Discovered in the Unbinding Pathway of Fluorinated Variants of the Trypsin-BPTI Complex Using Random Acceleration Molecular Dynamics Simulations. J Chem Inf Model 2024; 64:5194-5206. [PMID: 38870039 PMCID: PMC11234359 DOI: 10.1021/acs.jcim.4c00338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
The serine protease trypsin forms a tightly bound inhibitor complex with the bovine pancreatic trypsin inhibitor (BPTI). The complex is stabilized by the P1 residue Lys15, which interacts with negatively charged amino acids at the bottom of the S1 pocket. Truncating the P1 residue of wildtype BPTI to α-aminobutyric acid (Abu) leaves a complex with moderate inhibitor strength, which is held in place by additional hydrogen bonds at the protein-protein interface. Fluorination of the Abu residue partially restores the inhibitor strength. The mechanism with which fluorination can restore the inhibitor strength is unknown, and accurate computational investigation requires knowledge of the binding and unbinding pathways. The preferred unbinding pathway is likely to be complex, as encounter states have been described before, and unrestrained umbrella sampling simulations of these complexes suggest additional energetic minima. Here, we use random acceleration molecular dynamics to find a new metastable state in the unbinding pathway of Abu-BPTI variants and wildtype BPTI from trypsin, which we call the prebound state. The prebound state and the fully bound state differ by a substantial shift in the position, a slight shift in the orientation of the BPTI variants, and changes in the interaction pattern. Particularly important is the breaking of three hydrogen bonds around Arg17. Fluorination of the P1 residue lowers the energy barrier of the transition between the fully bound state and prebound state and also lowers the energy minimum of the prebound state. While the effect of fluorination is in general difficult to quantify, here, it is in part caused by favorable stabilization of a hydrogen bond between Gln194 and Cys14. The interaction pattern of the prebound state offers insights into the inhibitory mechanism of BPTI and might add valuable information for the design of serine protease inhibitors.
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Affiliation(s)
- Leon Wehrhan
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Arnimallee 22, Berlin 14195, Germany
| | - Bettina G Keller
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Arnimallee 22, Berlin 14195, Germany
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2
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Karadkhelkar NM, Gupta P, Barasa L, Chilamakuri R, Hlordzi CK, Acharekar N, Agarwal S, Chen ZS, Yoganathan S. Chemical Derivatization Leads to the Discovery Of Novel Analogs of Azotochelin, a Natural Siderophore, as Promising Anticancer Agents. ChemMedChem 2024; 19:e202300715. [PMID: 38598189 DOI: 10.1002/cmdc.202300715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/21/2024] [Accepted: 04/08/2024] [Indexed: 04/11/2024]
Abstract
Siderophores are structurally unique medicinal natural products and exhibit considerable therapeutic potential. Herein, we report the design and synthesis of azotochelin, a natural siderophore, and an extensive library of azotochelin analogs and their anticancer properties. We modified the carboxylic acid and the aromatic ring of azotochelin using various chemical motifs. We evaluated the cytotoxicity of the compounds against six different cancer cell lines (KB-3-1, SNB-19, MCF-7, K-562, SW-620, and NCI-H460) and a non-cancerous cell line (HEK-293). Among the twenty compounds tested, the IC50 values of nine compounds (14, 32, 35-40, and 54) were between 0.7 and 2.0 μM against a lung cancer cell line (NCI-H460). Moreover, several compounds showed good cytotoxicity profile (IC50 <10 μM) against the tested cancer cell lines. The flow cytometry analysis showed that compounds 36 and 38 induced apoptosis in NCI-H460 in a dose-dependent manner. The cell cycle analysis indicated that compounds 36 and 38 significantly arrested the cell cycle at the S phase to block cancer cell proliferation in the NCI-H460 cell line. The study has produced various novel azotochelin analogs that are potentially effective anticancer agents and lead compounds for further synthetic and medicinal chemistry exploration.
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Affiliation(s)
- Nishant M Karadkhelkar
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
- Current affiliation: The Scripps Research Institute, 10550 N Torrey Pines Rd., La Jolla, CA, 92037
| | - Pranav Gupta
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
| | - Leonard Barasa
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
- Current affiliation: Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA, 01605
| | - Rameswari Chilamakuri
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
| | - Christopher K Hlordzi
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
| | - Nikita Acharekar
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
| | - Saurabh Agarwal
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
| | - Zhe-Sheng Chen
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
| | - Sabesan Yoganathan
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Queens, NY, 11439 (S.Y.)
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3
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Wehrhan L, Keller BG. Fluorinated Protein-Ligand Complexes: A Computational Perspective. J Phys Chem B 2024; 128:5925-5934. [PMID: 38886167 PMCID: PMC11215785 DOI: 10.1021/acs.jpcb.4c01493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 05/28/2024] [Accepted: 05/30/2024] [Indexed: 06/20/2024]
Abstract
Fluorine is an element renowned for its unique properties. Its powerful capability to modulate molecular properties makes it an attractive substituent for protein binding ligands; however, the rational design of fluorination can be challenging with effects on interactions and binding energies being difficult to predict. In this Perspective, we highlight how computational methods help us to understand the role of fluorine in protein-ligand binding with a focus on molecular simulation. We underline the importance of an accurate force field, present fluoride channels as a showcase for biomolecular interactions with fluorine, and discuss fluorine specific interactions like the ability to form hydrogen bonds and interactions with aryl groups. We put special emphasis on the disruption of water networks and entropic effects.
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Affiliation(s)
- Leon Wehrhan
- Department of Chemistry,
Biology and Pharmacy, Freie Universität
Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Bettina G. Keller
- Department of Chemistry,
Biology and Pharmacy, Freie Universität
Berlin, Arnimallee 22, 14195 Berlin, Germany
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4
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Patel K, Karmakar S, Tothadi S, Reddy JP, Prabhakaran P. "Fluorine Effects" in Conformational Orchestration of α/β Hybrid Peptide with a 9-membered Pseudo β-Turn Motif. Chemistry 2024; 30:e202303757. [PMID: 38165894 DOI: 10.1002/chem.202303757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/04/2024]
Abstract
Fluorine, the tiny robust atom, with its unique features has captured the attention of scientists in recent times, especially in drug discovery with its integration in small molecules, peptides, and proteins. However, studies to understand the 'fluorine effects' on the conformation of molecules that follow 'beyond the rule of 5' are in the infancy yet significant in molecular design and function. For the first time, using short hybrid peptide sequence as an appropriate model, we examined the substitution effect (size, stereoelectronic effect, and hydrogen bonding) using X-ray diffraction, 2D-NMR, and CD studies. The comparative study on their folding patterns with hydrogen-substituted analogs can provide valuable insights into fluorinated substrates' design.
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Affiliation(s)
- Karma Patel
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar, India-, 382030
| | - Sintu Karmakar
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar, India-, 382030
| | - Srinu Tothadi
- Analytical and Environmental Sciences Division and Centralized Instrument Facility (AESD&CIF), CSIR-Central Salt & Marine Chemicals Research Institute (CSMCRI), Bhavnagar, India-, 364002
| | - J Prakasha Reddy
- School of Applied Material Sciences, Central University of Gujarat, Gandhinagar, India-, 382030
| | - Panchami Prabhakaran
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar, India-, 382030
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5
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Azizi K, Laio A, Hassanali A. Solvation thermodynamics from cavity shapes of amino acids. PNAS NEXUS 2023; 2:pgad239. [PMID: 37545648 PMCID: PMC10400782 DOI: 10.1093/pnasnexus/pgad239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 07/07/2023] [Accepted: 07/17/2023] [Indexed: 08/08/2023]
Abstract
According to common physical chemistry wisdom, the solvent cavities hosting a solute are tightly sewn around it, practically coinciding with its van der Waals surface. Solvation entropy is primarily determined by the surface and the volume of the cavity while enthalpy is determined by the solute-solvent interaction. In this work, we challenge this picture, demonstrating by molecular dynamics simulations that the cavities surrounding the 20 amino acids deviate significantly from the molecular surface. Strikingly, the shape of the cavity alone can be used to predict the solvation free energy, entropy, enthalpy, and hydrophobicity. Solute-solvent interactions involving the different chemical moieties of the amino acid, determine indirectly the cavity shape, and the properties of the branches but do not have to be taken explicitly into account in the prediction model.
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Affiliation(s)
- Khatereh Azizi
- The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy
| | - Alessandro Laio
- The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy
- SISSA, Via Bonomea 265, I-34136 Trieste, Italy
| | - Ali Hassanali
- The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy
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6
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Wehrhan L, Leppkes J, Dimos N, Loll B, Koksch B, Keller BG. Water Network in the Binding Pocket of Fluorinated BPTI-Trypsin Complexes─Insights from Simulation and Experiment. J Phys Chem B 2022; 126:9985-9999. [PMID: 36409613 DOI: 10.1021/acs.jpcb.2c05496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Structural waters in the S1 binding pocket of β-trypsin are critical for the stabilization of the complex of β-trypsin with its inhibitor bovine pancreatic trypsin inhibitor (BPTI). The inhibitor strength of BPTI can be modulated by replacing the critical lysine residue at the P1 position by non-natural amino acids. We study BPTI variants in which the critical Lys15 in BPTI has been replaced by α-aminobutyric acid (Abu) and its fluorinated derivatives monofluoroethylglycine (MfeGly), difluoroethylglycine (DfeGly), and trifluoroethylglycine (TfeGly). We investigate the hypothesis that additional water molecules in the binding pocket can form specific noncovalent interactions with the fluorinated side chains and thereby act as an extension of the inhibitors. We report potentials of mean force (PMF) of the unbinding process for all four complexes and enzyme activity inhibition assays. Additionally, we report the protein crystal structure of the Lys15MfeGly-BPTI-β-trypsin complex (pdb: 7PH1). Both experimental and computational data show a stepwise increase in inhibitor strength with increasing fluorination of the Abu side chain. The PMF additionally shows a minimum for the encounter complex and an intermediate state just before the bound state. In the bound state, the computational analysis of the structure and dynamics of the water molecules in the S1 pocket shows a highly dynamic network of water molecules that does not indicate a rigidification or stabilizing trend in regard to energetic properties that could explain the increase in inhibitor strength. The analysis of the energy and the entropy of the water molecules in the S1 binding pocket using grid inhomogeneous solvation theory confirms this result. Overall, fluorination systematically changes the binding affinity, but the effect cannot be explained by a persistent water network in the binding pocket. Other effects, such as the hydrophobicity of fluorinated amino acids and the stability of the encounter complex as well as the additional minimum in the potential of mean force in the bound state, likely influence the affinity more directly.
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Affiliation(s)
- Leon Wehrhan
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 22, Berlin14195, Germany
| | - Jakob Leppkes
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 20, Berlin14195, Germany
| | - Nicole Dimos
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 6, Berlin14195, Germany
| | - Bernhard Loll
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Takustr. 6, Berlin14195, Germany
| | - Beate Koksch
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 20, Berlin14195, Germany
| | - Bettina G Keller
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Institute of Chemistry and Biochemistry, Arnimallee 22, Berlin14195, Germany
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7
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Fluorinated Protein and Peptide Materials for Biomedical Applications. Pharmaceuticals (Basel) 2022; 15:ph15101201. [PMID: 36297312 PMCID: PMC9609677 DOI: 10.3390/ph15101201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/22/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Fluorination represents one of the most powerful modern design strategies to impart biomacromolecules with unique functionality, empowering them for widespread application in the biomedical realm. However, the properties of fluorinated protein materials remain unpredictable due to the heavy context-dependency of the surrounding atoms influenced by fluorine’s strong electron-withdrawing tendencies. This review aims to discern patterns and elucidate design principles governing the biochemical synthesis and rational installation of fluorine into protein and peptide sequences for diverse biomedical applications. Several case studies are presented to deconvolute the overgeneralized fluorous stabilization effect and critically examine the duplicitous nature of the resultant enhanced chemical and thermostability as it applies to use as biomimetic therapeutics, drug delivery vehicles, and bioimaging modalities.
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8
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Hohmann T, Dyrks M, Chowdhary S, Weber M, Nguyen D, Moschner J, Koksch B. Gram-Scale Asymmetric Synthesis of Fluorinated Amino Acids Using a Chiral Nickel(II) Complex. J Org Chem 2022; 87:10592-10604. [PMID: 35926217 DOI: 10.1021/acs.joc.2c00522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fluorinated amino acids play an important role in the field of peptide and protein engineering. Although numerous syntheses have been published in recent decades, strategies that allow routine access to fluorinated amino acids on a gram-scale have been poorly described. Furthermore, the described pathways that gain fluorinated amino acids are based on different synthetic strategies, making a uniform approach that uses similar starting materials highly beneficial. Chiral Ni(II) complexes were introduced as powerful tools in the synthesis of noncanonical amino acids. In this work, we present a strategy for the synthesis of a diverse range of fluorinated amino acids based on the corresponding Ni(II) complex from which the products can be obtained in enantiopure form (99% ee) on a gram-scale. In addition, we describe an optimized procedure for the synthesis of alkyl iodide building blocks that are required for the alkylation reactions with the corresponding Ni(II) complex. Finally, we characterized the synthesized fluorinated amino acids with regard to their hydrophobicity and α-helix propensity.
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Affiliation(s)
- Thomas Hohmann
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, Berlin, 14195Berlin, Germany
| | - Michael Dyrks
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, Berlin, 14195Berlin, Germany
| | - Suvrat Chowdhary
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, Berlin, 14195Berlin, Germany
| | - Manuela Weber
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Fabeckstraße 34/36, Berlin, 14195Berlin, Germany
| | - Duy Nguyen
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, Berlin, 14195Berlin, Germany
| | - Johann Moschner
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, Berlin, 14195Berlin, Germany
| | - Beate Koksch
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, Berlin, 14195Berlin, Germany
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9
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Chowdhary S, Schmidt RF, Sahoo AK, Tom Dieck T, Hohmann T, Schade B, Brademann-Jock K, Thünemann AF, Netz RR, Gradzielski M, Koksch B. Rational design of amphiphilic fluorinated peptides: evaluation of self-assembly properties and hydrogel formation. NANOSCALE 2022; 14:10176-10189. [PMID: 35796261 DOI: 10.1039/d2nr01648f] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Advanced peptide-based nanomaterials composed of self-assembling peptides (SAPs) are of emerging interest in pharmaceutical and biomedical applications. The introduction of fluorine into peptides, in fact, offers unique opportunities to tune their biophysical properties and intermolecular interactions. In particular, the degree of fluorination plays a crucial role in peptide engineering as it can be used to control the characteristics of fluorine-specific interactions and, thus, peptide conformation and self-assembly. Here, we designed and explored a series of amphipathic peptides by incorporating the fluorinated amino acids (2S)-4-monofluoroethylglycine (MfeGly), (2S)-4,4-difluoroethylglycine (DfeGly) and (2S)-4,4,4-trifluoroethylglycine (TfeGly) as hydrophobic components. This approach enabled studying the impact of fluorination on secondary structure formation and peptide self-assembly on a systematic basis. We show that the interplay between polarity and hydrophobicity, both induced differentially by varying degrees of side chain fluorination, does affect peptide folding significantly. A greater degree of fluorination promotes peptide fibrillation and subsequent formation of physical hydrogels in physiological conditions. Molecular simulations revealed the key role played by electrostatically driven intra-chain and inter-chain contact pairs that are modulated by side chain fluorination and give insights into the different self-organization behaviour of selected peptides. Our study provides a systematic report about the distinct features of fluorinated oligomeric peptides with potential applications as peptide-based biomaterials.
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Affiliation(s)
- Suvrat Chowdhary
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, 14195 Berlin, Germany.
| | - Robert Franz Schmidt
- Institute of Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Anil Kumar Sahoo
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Tiemo Tom Dieck
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, 14195 Berlin, Germany.
| | - Thomas Hohmann
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, 14195 Berlin, Germany.
| | - Boris Schade
- Institute of Chemistry and Biochemistry and Core Facility BioSupraMol, Freie Universität Berlin, Fabeckstraße 36a, 14195 Berlin, Germany
| | - Kerstin Brademann-Jock
- Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, 12205 Berlin, Germany
| | - Andreas F Thünemann
- Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, 12205 Berlin, Germany
| | - Roland R Netz
- Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Michael Gradzielski
- Institute of Chemistry, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany
| | - Beate Koksch
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 20, 14195 Berlin, Germany.
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10
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Yang D, Gronenborn AM, Chong LT. Development and Validation of Fluorinated, Aromatic Amino Acid Parameters for Use with the AMBER ff15ipq Protein Force Field. J Phys Chem A 2022; 126:2286-2297. [PMID: 35352936 PMCID: PMC9014858 DOI: 10.1021/acs.jpca.2c00255] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/15/2022] [Indexed: 12/27/2022]
Abstract
We developed force field parameters for fluorinated, aromatic amino acids enabling molecular dynamics (MD) simulations of fluorinated proteins. These parameters are tailored to the AMBER ff15ipq protein force field and enable the modeling of 4, 5, 6, and 7F-tryptophan, 3F- and 3,5F-tyrosine, and 4F- or 4-CF3-phenylalanine. The parameters include 181 unique atomic charges derived using the implicitly polarized charge (IPolQ) scheme in the presence of SPC/Eb explicit water molecules and 9 unique bond, angle, or torsion terms. Our simulations of benchmark peptides and proteins maintain expected conformational propensities on the μs time scale. In addition, we have developed an open-source Python program to calculate fluorine relaxation rates from MD simulations. The extracted relaxation rates from protein simulations are in good agreement with experimental values determined by 19F NMR. Collectively, our results illustrate the power and robustness of the IPolQ lineage of force fields for modeling the structure and dynamics of fluorine-containing proteins at the atomic level.
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Affiliation(s)
- Darian
T. Yang
- Molecular
Biophysics and Structural Biology Graduate Program, University of Pittsburgh and Carnegie Mellon University, Pittsburgh, Pennsylvania 15260, United States
- Department
of Structural Biology, University of Pittsburgh
School of Medicine, Pittsburgh, Pennsylvania 15260, United States
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Angela M. Gronenborn
- Department
of Structural Biology, University of Pittsburgh
School of Medicine, Pittsburgh, Pennsylvania 15260, United States
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Lillian T. Chong
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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11
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Gawor A, Gajewski Z, Paczek L, Czarkowska-Paczek B, Konopka A, Wryk G, Bulska E. Fluorine-Containing Drug Administration in Rats Results in Fluorination of Selected Proteins in Liver and Brain Tissue. Int J Mol Sci 2022; 23:ijms23084202. [PMID: 35457021 PMCID: PMC9028303 DOI: 10.3390/ijms23084202] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 03/31/2022] [Accepted: 04/09/2022] [Indexed: 12/26/2022] Open
Abstract
In many pharmaceuticals, a hydrogen atom or hydroxyl group is replaced by a fluorine to increase bioavailability and biostability. The fate of fluorine released from fluorine-containing drugs is not well investigated. The aim of this study was to examine possible fluorination of proteins in rat liver and brain after administration of the fluorinated drug cinacalcet. We assigned 18 Wistar rats to a control group (n = 6) and a group treated with cinacalcet (2 mg kg−1/body weight, 5 days/week), divided into 7 day (n = 6) and 21 day (n = 6) treatment subgroups. Fluorinated proteins were identified using a free proteomics approach; chromatographic separation and analysis by high-resolution mass spectrometry; peptide/protein identification using the Mascot search algorithm; manual verification of an experimentally generated MS/MS spectrum with the theoretical MS/MS spectrum of identified fluorinated peptides. Three fluorinated proteins (spectrin beta chain; carbamoyl-phosphate synthase [ammonia], mitochondrial; 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 1) were identified in the liver and four (spectrin beta chain, dihydropyrimidinase-related protein 4, prominin-2, dihydropyrimidinase-related protein 4) in the brain tissue after 21 days of cinacalcet treatment, but not in the control group. Introduction of fluorine into an organism by administration of fluorinated drugs results in tissue-specific fluorination of proteins.
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Affiliation(s)
- Andrzej Gawor
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland; (A.G.); (A.K.); (G.W.); (E.B.)
| | - Zdzislaw Gajewski
- Center for Translational Medicine, Warsaw University of Life Science, Nowoursynowska 100, 02-797 Warsaw, Poland;
| | - Leszek Paczek
- Department of Immunology, Transplantology and Internal Diseases, Medical University of Warsaw, Nowogrodzka 59, 02-006 Warsaw, Poland;
- Department of Bioinformatics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warsaw, Poland
| | - Bozena Czarkowska-Paczek
- Department of Clinical Nursing, Medical University of Warsaw, Ciolka Street 27, 01-445 Warsaw, Poland
- Correspondence: ; Tel./Fax: +48-22-836-0972
| | - Anna Konopka
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland; (A.G.); (A.K.); (G.W.); (E.B.)
| | - Grzegorz Wryk
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland; (A.G.); (A.K.); (G.W.); (E.B.)
| | - Ewa Bulska
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Zwirki i Wigury 101, 02-089 Warsaw, Poland; (A.G.); (A.K.); (G.W.); (E.B.)
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12
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Leppkes J, Dimos N, Loll B, Hohmann T, Dyrks M, Wieseke A, Keller BG, Koksch B. Fluorine-induced polarity increases inhibitory activity of BPTI towards chymotrypsin. RSC Chem Biol 2022; 3:773-782. [PMID: 35755190 PMCID: PMC9175108 DOI: 10.1039/d2cb00018k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 05/06/2022] [Indexed: 11/21/2022] Open
Abstract
Substituting the P1 position in bovine pancreatic trypsin inhibitor (BPTI) is known to heavily influence its inhibitory activity towards serine proteases. Side-chain fluorinated aliphatic amino acids have been shown to alter numerous properties of peptides and proteins and thus are of interest in the context of BPTI. In our study, we systematically investigated the site-specific incorporation of non-canonical amino acids into BPTI by microwave-assisted solid-phase peptide synthesis (SPPS). Inhibitor activity of the variants was tested towards the serine protease α-chymotrypsin. We observed enhanced inhibition of two fluorinated BPTIs compared to wild type and hydrocarbon variants. To further investigate the complexes, we performed X-ray structure analysis. Our findings underline the power fluorine offers as a tool in protein engineering to beneficially alter the effects on phenomena as protein–protein interactions. Site-specific incorporation of fluorine into bovine pancreatic trypsin inhibitor (BPTI) through chemical protein synthesis, followed by investigations of influence of fluorine on inhibition properties towards serine protease chymotrypsin.![]()
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Affiliation(s)
- Jakob Leppkes
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin Arnimallee 20 14195 Berlin Germany
| | - Nicole Dimos
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Structural Biochemistry, Freie Universität Berlin Takustr. 6 14195 Berlin Germany
| | - Bernhard Loll
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Structural Biochemistry, Freie Universität Berlin Takustr. 6 14195 Berlin Germany
| | - Thomas Hohmann
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin Arnimallee 20 14195 Berlin Germany
| | - Michael Dyrks
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin Arnimallee 20 14195 Berlin Germany
| | - Ariane Wieseke
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin Arnimallee 20 14195 Berlin Germany
| | - Bettina G Keller
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin Arnimallee 22 14195 Berlin Germany
| | - Beate Koksch
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin Arnimallee 20 14195 Berlin Germany
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13
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Bodero L, Guitot K, Lensen N, Lequin O, Brigaud T, Ongeri S, Chaume G. Introducing the Chiral Constrained α-Trifluoromethylalanine in Aib foldamers to Control, Quantify and Assign the Helical Screw-Sense. Chemistry 2021; 28:e202103887. [PMID: 34890083 DOI: 10.1002/chem.202103887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Indexed: 11/11/2022]
Abstract
Oligomers of α-aminoisobutyric acid (Aib) are achiral peptides that adopt 3 10 helical structures with equal population of left- and right-handed conformers. Yet, the screw-sense preference of the helical chain may be controlled by a single chiral residue located at one terminus. 1 H and 19 F NMR, X-ray crystallography and circular dichroism studies on new Aib oligomers show that the incorporation of a chiral quaternary α-trifluoromethylalanine at their N -terminus induces a reversal of the screw-sense preference of the 3 10 -helix compared to that of a non-fluorinated analogue having an l-α-methyl valine residue. This work demonstrates that, among the many particular properties of introducing a trifluoromethyl group into foldamers, its stereo-electronic properties are of major interest to control the helical screw sense. Its use as an easy-to-handle 19 F NMR probe to reliably determine both the magnitude of the screw-sense preference and its sign assignment is also of remarkable interest.
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Affiliation(s)
| | | | | | - Olivier Lequin
- Sorbonne Université Campus Pierre et Marie Curie: Sorbonne Universite Campus Pierre et Marie Curie, chemistry, FRANCE
| | | | | | - Grégory Chaume
- CY Cergy Paris Universite, Chemistry, 5 mail Gay Lussac, 95000, Cergy-Pontoise, FRANCE
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14
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Natural and Synthetic Halogenated Amino Acids-Structural and Bioactive Features in Antimicrobial Peptides and Peptidomimetics. Molecules 2021; 26:molecules26237401. [PMID: 34885985 PMCID: PMC8659048 DOI: 10.3390/molecules26237401] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 11/16/2021] [Accepted: 11/26/2021] [Indexed: 11/17/2022] Open
Abstract
The 3D structure and surface characteristics of proteins and peptides are crucial for interactions with receptors or ligands and can be modified to some extent to modulate their biological roles and pharmacological activities. The introduction of halogen atoms on the side-chains of amino acids is a powerful tool for effecting this type of tuning, influencing both the physico-chemical and structural properties of the modified polypeptides, helping to first dissect and then rationally modify features that affect their mode of action. This review provides examples of the influence of different types of halogenation in amino acids that replace native residues in proteins and peptides. Examples of synthetic strategies for obtaining halogenated amino acids are also provided, focusing on some representative compounds and their biological effects. The role of halogenation in native and designed antimicrobial peptides (AMPs) and their mimetics is then discussed. These are in the spotlight for the development of new antimicrobial drugs to counter the rise of antibiotic-resistant pathogens. AMPs represent an interesting model to study the role that natural halogenation has on their mode of action and also to understand how artificially halogenated residues can be used to rationally modify and optimize AMPs for pharmaceutical purposes.
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15
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Yan Y, Chen J, Li K, Zou D, Deng Y, Li D. A novel neutral-base coupling synergistic extraction system of Cyanex923 and primary amine N1923 for the recovery of cerium(IV) and fluorine from sulfuric acid medium. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.118026] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Yang B, Liu H, Liu Z, Doenen R, Nash MA. Influence of Fluorination on Single-Molecule Unfolding and Rupture Pathways of a Mechanostable Protein Adhesion Complex. NANO LETTERS 2020; 20:8940-8950. [PMID: 33191756 PMCID: PMC7729889 DOI: 10.1021/acs.nanolett.0c04178] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/08/2020] [Indexed: 05/25/2023]
Abstract
We investigated the influence of fluorination on unfolding and unbinding reaction pathways of a mechanostable protein complex comprising the tandem dyad XModule-Dockerin bound to Cohesin. Using single-molecule atomic force spectroscopy, we mapped the energy landscapes governing the unfolding and unbinding reactions. We then used sense codon suppression to substitute trifluoroleucine in place of canonical leucine globally in XMod-Doc. Although TFL substitution thermally destabilized XMod-Doc, it had little effect on XMod-Doc:Coh binding affinity at equilibrium. When we mechanically dissociated global TFL-substituted XMod-Doc from Coh, we observed the emergence of a new unbinding pathway with a lower energy barrier. Counterintuitively, when fluorination was restricted to Doc, we observed mechano-stabilization of the non-fluorinated neighboring XMod domain. This suggests that intramolecular deformation is modulated by fluorination and highlights the differences between equilibrium thermostability and non-equilibrium mechanostability. Future work is poised to investigate fluorination as a means to modulate mechanical properties of synthetic proteins and hydrogels.
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Affiliation(s)
- Byeongseon Yang
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
- Department
of Biosystems Science and Engineering, ETH
Zurich, 4058 Basel, Switzerland
| | - Haipei Liu
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
- Department
of Biosystems Science and Engineering, ETH
Zurich, 4058 Basel, Switzerland
| | - Zhaowei Liu
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
- Department
of Biosystems Science and Engineering, ETH
Zurich, 4058 Basel, Switzerland
| | - Regina Doenen
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
- Department
of Biosystems Science and Engineering, ETH
Zurich, 4058 Basel, Switzerland
| | - Michael A. Nash
- Department
of Chemistry, University of Basel, 4058 Basel, Switzerland
- Department
of Biosystems Science and Engineering, ETH
Zurich, 4058 Basel, Switzerland
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17
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Fluorine induced conformational switching and modulation in photophysical properties of 7-fluorotryptophan: Spectroscopic, quantum chemical calculation and molecular dynamics simulation studies. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2020. [DOI: 10.1016/j.jpap.2020.100011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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18
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Muralidharan A, Schmidt JR, Yethiraj A. Solvation Induced Ring Puckering Effect in Fluorinated Prolines and Its Inclusion in Classical Force Fields. J Phys Chem B 2020; 124:5899-5906. [PMID: 32551633 DOI: 10.1021/acs.jpcb.0c04312] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Strategic incorporation of fluorinated prolines can accelerate folding and increase thermal stability of proteins. It has been suggested that this behavior emerges from puckering effects induced by fluorination of the proline ring. We use electronic structure calculations to characterize the potential energy surface (PES) along puckering coordinates for a simple dipeptide model of proline and its fluorinated derivatives. Significant shifts in puckering trends between gas phase and implicit solvent calculations shed light on the effect of solvation on electronic structure and conformational preferences of the ring. This solvation induced puckering effect is previously unknown in the context of prolines. The PES based on implicit solvent is then utilized to construct a correction for a classical force field. The corrected force field accurately captures the experimental conformational equilibrium including the coupling between ring puckering and cis-trans isomerism in fluorinated prolines. This method can be extended to other rings and substituents besides fluorine.
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Affiliation(s)
- Ajay Muralidharan
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconson 53706, United States
| | - J R Schmidt
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconson 53706, United States
| | - Arun Yethiraj
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconson 53706, United States
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19
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Zhao J, Wu L, Zhai S, Lin P, Guo S. Construction expression and immunogenicity of a novel trivalent outer membrane protein (OmpU-A-II) from three bacterial pathogens in Japanese eels (Anguilla japonica). JOURNAL OF FISH DISEASES 2020; 43:519-529. [PMID: 32285473 DOI: 10.1111/jfd.13132] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/12/2019] [Accepted: 12/13/2019] [Indexed: 06/11/2023]
Abstract
Vibrio vulnificus, Edwardsiella anguillarum and Aeromonas hydrophila are three common bacterial pathogens in cultivated eels. To protect farming eels from infection by these pathogens, a trivalent outer membrane protein (OMP) containing partial sequences of OmpU from V. vulnificus, OmpA from E. anguillarum and OmpII from A. hydrophila was expressed and purified; then, the OMP was used as a vaccine to immunize Japanese eels (Anguilla japonica). Whole-blood cell proliferation, antibody titres and complement and lysozyme activities were detected at different days post-immunization (dpi), and the relative per cent survival (RPS) was determined after eels were infected with V. vulnificus, E. anguillarum or A. hydrophila at 28 dpi. The results showed that the OMP significantly stimulates the antibody titres. At 14 days after the challenge (i.e. at 28 dpi), the RPS of OMP against V. vulnificus, E. anguillarum and A. hydrophila was 20%, 70% and 11.1%, respectively. The construction, expression and immunogenicity of a trivalent Omp were reported for the first time, and this study will provide a valuable reference for the development of fish multiplex vaccines.
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Affiliation(s)
- Jinping Zhao
- Fisheries College, Jimei University, Xiamen, China
- Engineering Research Center of the Modern Industry Technology for Eel. Ministry of Education of PRC, Xiamen, China
| | - Liqun Wu
- College of Overseas Education, Jimei University, Xiamen, China
| | - Shaowei Zhai
- Fisheries College, Jimei University, Xiamen, China
- Engineering Research Center of the Modern Industry Technology for Eel. Ministry of Education of PRC, Xiamen, China
| | - Peng Lin
- Fisheries College, Jimei University, Xiamen, China
- Engineering Research Center of the Modern Industry Technology for Eel. Ministry of Education of PRC, Xiamen, China
| | - Songlin Guo
- Fisheries College, Jimei University, Xiamen, China
- Engineering Research Center of the Modern Industry Technology for Eel. Ministry of Education of PRC, Xiamen, China
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20
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Robalo JR, Mendes de Oliveira D, Imhof P, Ben-Amotz D, Vila Verde A. Quantifying how step-wise fluorination tunes local solute hydrophobicity, hydration shell thermodynamics and the quantum mechanical contributions of solute–water interactions. Phys Chem Chem Phys 2020; 22:22997-23008. [DOI: 10.1039/d0cp04205f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Locally tuning solute–water interactions with fluorination.
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Affiliation(s)
- João R. Robalo
- Department of Theory & Bio-Systems
- Max Planck Institute for Colloids and Interfaces
- Science Park
- Potsdam 14476
- Germany
| | | | - Petra Imhof
- Institute for Theoretical Physics
- Free University of Berlin
- 14195 Berlin
- Germany
| | - Dor Ben-Amotz
- Purdue University
- Department of Chemistry
- West Lafayette
- USA
| | - Ana Vila Verde
- Department of Theory & Bio-Systems
- Max Planck Institute for Colloids and Interfaces
- Science Park
- Potsdam 14476
- Germany
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21
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Kumar A, Patwari GN. Hydration of Fluorobenzenes: A Molecular Dynamics Simulation Investigation. J Indian Inst Sci 2019. [DOI: 10.1007/s41745-019-00157-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Kumar A, Mahato J, Dixit M, Patwari GN. Progressive Hydrophobicity of Fluorobenzenes. J Phys Chem B 2019; 123:10083-10088. [PMID: 31661279 DOI: 10.1021/acs.jpcb.9b08057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The potentials of mean force for the dimers of fluorobenzenes sample both π-stacked and T-shaped structures for partially fluorinated benzenes, namely, 1,4-difluorobenzene, 1,3,5-trifluorobenzene, and 1,2,4,5-tetrafluorobenzene, and sample only the T-shaped structures for benzene and hexafluorobenzene. While the free energy for the dimerization in water is very weakly dependent on the number of fluorine atoms, the formation of π-stacked structures is entropy-driven and the T-shaped structures appear due to an enthalpic minimum. Interestingly, the solvation behavior suggests that the accumulation of water around the contact and solvent-separated pairs decreases with the increase in the number of fluorine atoms, which signifies progressive hydrophobicity of fluorobenzenes.
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Affiliation(s)
- Anuj Kumar
- Department of Chemistry , Indian Institute of Technology Bombay , Powai, Mumbai 400076 India.,Prithwi Chand Vigyan College, Jai Prakash Vishwavidyalaya , Chapra , Saran, Bihar 841301 , India
| | - Jaladhar Mahato
- Department of Chemistry , Indian Institute of Technology Bombay , Powai, Mumbai 400076 India
| | - Mayank Dixit
- Department of Chemistry , Indian Institute of Technology Bombay , Powai, Mumbai 400076 India
| | - G Naresh Patwari
- Department of Chemistry , Indian Institute of Technology Bombay , Powai, Mumbai 400076 India
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23
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Robalo JR, Streacker LM, Mendes de Oliveira D, Imhof P, Ben-Amotz D, Verde AV. Hydrophobic but Water-Friendly: Favorable Water–Perfluoromethyl Interactions Promote Hydration Shell Defects. J Am Chem Soc 2019; 141:15856-15868. [DOI: 10.1021/jacs.9b06862] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- João R. Robalo
- Department of Theory & Bio-systems, Max Planck Institute for Colloids and Interfaces, Science Park, Potsdam 14476, Germany
| | - Louis M. Streacker
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | | | - Petra Imhof
- Institute for Theoretical Physics, Free University of Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Dor Ben-Amotz
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Ana Vila Verde
- Department of Theory & Bio-systems, Max Planck Institute for Colloids and Interfaces, Science Park, Potsdam 14476, Germany
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24
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Green Choline Amino Acid Ionic Liquid Aqueous Two-Phase Extraction Coupled with HPLC for Analysis Sunset Yellow in Beverages. FOOD ANAL METHOD 2019. [DOI: 10.1007/s12161-019-01603-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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