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Miles SA, Nillama JA, Hunter L. Tinker, Tailor, Soldier, Spy: The Diverse Roles That Fluorine Can Play within Amino Acid Side Chains. Molecules 2023; 28:6192. [PMID: 37687021 PMCID: PMC10489206 DOI: 10.3390/molecules28176192] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
Side chain-fluorinated amino acids are useful tools in medicinal chemistry and protein science. In this review, we outline some general strategies for incorporating fluorine atom(s) into amino acid side chains and for elaborating such building blocks into more complex fluorinated peptides and proteins. We then describe the diverse benefits that fluorine can offer when located within amino acid side chains, including enabling 19F NMR and 18F PET imaging applications, enhancing pharmacokinetic properties, controlling molecular conformation, and optimizing target-binding.
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Affiliation(s)
| | | | - Luke Hunter
- School of Chemistry, The University of New South Wales (UNSW), Sydney 2052, Australia
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2
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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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3
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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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4
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Borgini M, Wipf P. Stereoselective synthesis of δ-fluorinated isoleucines exploiting consecutive C(sp3)-H bond activations. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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5
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Huhmann S, Nyakatura EK, Rohrhofer A, Moschner J, Schmidt B, Eichler J, Roth C, Koksch B. Systematic Evaluation of Fluorination as Modification for Peptide-Based Fusion Inhibitors against HIV-1 Infection. Chembiochem 2021; 22:3443-3451. [PMID: 34605595 PMCID: PMC9297971 DOI: 10.1002/cbic.202100417] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 10/04/2021] [Indexed: 01/01/2023]
Abstract
With the emergence of novel viruses, the development of new antivirals is more urgent than ever. A key step in human immunodeficiency virus type 1 (HIV-1) infection is six-helix bundle formation within the envelope protein subunit gp41. Selective disruption of bundle formation by peptides has been shown to be effective; however, these drugs, exemplified by T20, are prone to rapid clearance from the patient. The incorporation of non-natural amino acids is known to improve these pharmacokinetic properties. Here, we evaluate a peptide inhibitor in which a critical Ile residue is replaced by fluorinated analogues. We characterized the influence of the fluorinated analogues on the biophysical properties of the peptide. Furthermore, we show that the fluorinated peptides can block HIV-1 infection of target cells at nanomolar levels. These findings demonstrate that fluorinated amino acids are appropriate tools for the development of novel peptide therapeutics.
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Affiliation(s)
- Susanne Huhmann
- Freie Universität BerlinDepartment of Biology, Chemistry and PharmacyInstitute of Chemistry and BiochemistryArnimallee 2014195BerlinGermany
| | - Elisabeth K. Nyakatura
- Freie Universität BerlinDepartment of Biology, Chemistry and PharmacyInstitute of Chemistry and BiochemistryArnimallee 2014195BerlinGermany
- Antibody Engineering Tri-Institutional Therapeutics Discovery Institute417 East 68th Street, 19 Floor North, P: 646-888-2003New YorkNY 10021USA
| | - Anette Rohrhofer
- Institute of Clinical Microbiology and HygieneRegensburg University HospitalFranz-Josef-Strauß-Allee 1193053RegensburgGermany
| | - Johann Moschner
- Freie Universität BerlinDepartment of Biology, Chemistry and PharmacyInstitute of Chemistry and BiochemistryArnimallee 2014195BerlinGermany
| | - Barbara Schmidt
- Institute of Clinical Microbiology and HygieneRegensburg University HospitalFranz-Josef-Strauß-Allee 1193053RegensburgGermany
| | - Jutta Eichler
- Friedrich-Alexander-Universität Erlangen-NürnbergDepartment Chemie und PharmazieNikolaus-Fiebiger-Str. 1091058ErlangenGermany
| | - Christian Roth
- Max Planck Institute of Colloids and InterfacesBiomolecular SystemsArnimallee 2214195BerlinGermany
| | - Beate Koksch
- Freie Universität BerlinDepartment of Biology, Chemistry and PharmacyInstitute of Chemistry and BiochemistryArnimallee 2014195BerlinGermany
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6
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Moschner J, Stulberg V, Fernandes R, Huhmann S, Leppkes J, Koksch B. Approaches to Obtaining Fluorinated α-Amino Acids. Chem Rev 2019; 119:10718-10801. [PMID: 31436087 DOI: 10.1021/acs.chemrev.9b00024] [Citation(s) in RCA: 171] [Impact Index Per Article: 34.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Fluorine does not belong to the pool of chemical elements that nature uses to build organic matter. However, chemists have exploited the unique properties of fluorine and produced countless fluoro-organic compounds without which our everyday lives would be unimaginable. The incorporation of fluorine into amino acids established a completely new class of amino acids and their properties, and those of the biopolymers constructed from them are extremely interesting. Increasing interest in this class of amino acids caused the demand for robust and stereoselective synthetic protocols that enable straightforward access to these building blocks. Herein, we present a comprehensive account of the literature in this field going back to 1995. We place special emphasis on a particular fluorination strategy. The four main sections describe fluorinated versions of alkyl, cyclic, aromatic amino acids, and also nickel-complexes to access them. We progress by one carbon unit increments. Special cases of amino acids for which there is no natural counterpart are described at the end of each section. Synthetic access to each of the amino acids is summarized in form of a table at the end of this article with the aim to make the information easily accessible to the reader.
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Affiliation(s)
- Johann Moschner
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry , Freie Universität Berlin , Takustr. 3 , 14195 Berlin , Germany
| | - Valentina Stulberg
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry , Freie Universität Berlin , Takustr. 3 , 14195 Berlin , Germany
| | - Rita Fernandes
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry , Freie Universität Berlin , Takustr. 3 , 14195 Berlin , Germany
| | - Susanne Huhmann
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry , Freie Universität Berlin , Takustr. 3 , 14195 Berlin , Germany
| | - Jakob Leppkes
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry , Freie Universität Berlin , Takustr. 3 , 14195 Berlin , Germany
| | - Beate Koksch
- Department of Biology, Chemistry and Pharmacy, Institute of Chemistry and Biochemistry , Freie Universität Berlin , Takustr. 3 , 14195 Berlin , Germany
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Huhmann S, Koksch B. Fine-Tuning the Proteolytic Stability of Peptides with Fluorinated Amino Acids. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800803] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Susanne Huhmann
- Institute of Chemistry and Biochemistry; Freie Universität Berlin; Takustr. 3 14169 Berlin Germany
| | - Beate Koksch
- Institute of Chemistry and Biochemistry; Freie Universität Berlin; Takustr. 3 14169 Berlin Germany
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8
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Huhmann S, Stegemann AK, Folmert K, Klemczak D, Moschner J, Kube M, Koksch B. Position-dependent impact of hexafluoroleucine and trifluoroisoleucine on protease digestion. Beilstein J Org Chem 2017; 13:2869-2882. [PMID: 29564015 PMCID: PMC5753150 DOI: 10.3762/bjoc.13.279] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/13/2017] [Indexed: 12/22/2022] Open
Abstract
Rapid digestion by proteases limits the application of peptides as therapeutics. One strategy to increase the proteolytic stability of peptides is the modification with fluorinated amino acids. This study presents a systematic investigation of the effects of fluorinated leucine and isoleucine derivatives on the proteolytic stability of a peptide that was designed to comprise substrate specificities of different proteases. Therefore, leucine, isoleucine, and their side-chain fluorinated variants were site-specifically incorporated at different positions of this peptide resulting in a library of 13 distinct peptides. The stability of these peptides towards proteolysis by α-chymotrypsin, pepsin, proteinase K, and elastase was studied, and this process was followed by an FL-RP-HPLC assay in combination with mass spectrometry. In a few cases, we observed an exceptional increase in proteolytic stability upon introduction of the fluorine substituents. The opposite phenomenon was observed in other cases, and this may be explained by specific interactions of fluorinated residues with the respective enzyme binding sites. Noteworthy is that 5,5,5-trifluoroisoleucine is able to significantly protect peptides from proteolysis by all enzymes included in this study when positioned N-terminal to the cleavage site. These results provide valuable information for the application of fluorinated amino acids in the design of proteolytically stable peptide-based pharmaceuticals.
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Affiliation(s)
- Susanne Huhmann
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Anne-Katrin Stegemann
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Kristin Folmert
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Damian Klemczak
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Johann Moschner
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Michelle Kube
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Beate Koksch
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
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10
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Berger AA, Völler JS, Budisa N, Koksch B. Deciphering the Fluorine Code-The Many Hats Fluorine Wears in a Protein Environment. Acc Chem Res 2017; 50:2093-2103. [PMID: 28803466 DOI: 10.1021/acs.accounts.7b00226] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Deciphering the fluorine code is how we describe not only the focus of this Account, but also the systematic approach to studying the impact of fluorine's incorporation on the properties of peptides and proteins used by our groups and others. The introduction of fluorine has been shown to impart favorable, but seldom predictable, properties to peptides and proteins, but up until about two decades ago the outcomes of fluorine modification of peptides and proteins were largely left to chance. Driven by the motivation to extend the application of the unique properties of the element fluorine from medicinal and agro chemistry to peptide and protein engineering we have established extensive research programs that enable the systematic investigation of effects that accompany the introduction of fluorine into this class of biopolymers. The introduction of fluorine into amino acids offers a universe of options for modifications with regard to number and position of fluorine substituents in the amino acid side chain. Moreover, it is important to emphasize that the consequences of incorporating the C-F bond into a biopolymer can be attributed to two distinct yet related phenomena: (i) the fluorine substituent can directly engage in intermolecular interactions with its environment and/or (ii) the other functional groups present in the molecule can be influenced by the electron withdrawing nature of this element (intramolecular) and in turn interact differently with their immediate environment (intermolecular). Based on our studies, we have shown that a change in number and/or position of as subtle as one single fluorine substituent has the power to considerably modify key properties of amino acids such as hydrophobicity, polarity, and secondary structure propensity. These properties are crucial factors in peptide and protein engineering, and thus, fluorinated amino acids can be applied to fine-tune properties such as protein folding, proteolytic stability, and protein-protein interactions provided we understand and become able to predict the outcome of a fluorine substitution in this context. With this Account, we attempt to analyze information we gained from our recent projects on how the nature of the fluorine atom and C-F bond influence four key properties of peptides and proteins: peptide folding, protein-protein interactions, ribosomal translation, and protease stability. These results impressively show why the introduction of fluorine creates a new class of amino acids with a repertoire of functionalities that is unique to the world of proteins and in some cases orthogonal to the set of canonical and natural amino acids. Our concluding statements aim to offer a few conserved design principles that have emerged from systematic studies over the last two decades; in this way, we hope to advance the field of peptide and protein engineering based on the judicious introduction of fluorinated building blocks.
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Affiliation(s)
- Allison Ann Berger
- Institute
of Chemistry and Biochemistry − Organic Chemistry, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany
| | - Jan-Stefan Völler
- Institute
of Chemistry, Technische Universität Berlin, Müller-Breslau-Str. 10, 10623 Berlin Germany
| | - Nediljko Budisa
- Institute
of Chemistry, Technische Universität Berlin, Müller-Breslau-Str. 10, 10623 Berlin Germany
| | - Beate Koksch
- Institute
of Chemistry and Biochemistry − Organic Chemistry, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany
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11
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Perfluoroalkylation of Alkenes by Frustrated Lewis Pairs. Chemistry 2016; 22:17177-17181. [DOI: 10.1002/chem.201604414] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Indexed: 11/07/2022]
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12
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Huhmann S, Nyakatura EK, Erdbrink H, Gerling UI, Czekelius C, Koksch B. Effects of single substitutions with hexafluoroleucine and trifluorovaline on the hydrophobic core formation of a heterodimeric coiled coil. J Fluor Chem 2015. [DOI: 10.1016/j.jfluchem.2015.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Five-Membered Ring Systems with O & N Atoms. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/b978-0-08-100017-5.00011-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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14
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Gerling UIM, Salwiczek M, Cadicamo CD, Erdbrink H, Czekelius C, Grage SL, Wadhwani P, Ulrich AS, Behrends M, Haufe G, Koksch B. Fluorinated amino acids in amyloid formation: a symphony of size, hydrophobicity and α-helix propensity. Chem Sci 2014. [DOI: 10.1039/c3sc52932k] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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