1
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Bhatt MR, Zondlo NJ. Electronic Control of Polyproline II Helix Stability via the Identity of Acyl Capping Groups: the Pivaloyl Group Particularly Promotes PPII. Chemistry 2024:e202401454. [PMID: 38661017 DOI: 10.1002/chem.202401454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 04/26/2024]
Abstract
The type II polyproline helix (PPII) is a fundamental secondary structure of proteins, important in globular proteins, in intrinsically disordered proteins, and at protein-protein interfaces. PPII is stabilized in part by n→π* interactions between consecutive carbonyls, via electron delocalization between an electron-donor carbonyl lone pair (n) and an electron-acceptor carbonyl (π*) on the subsequent residue. We previously demonstrated that changes to the electronic properties of the acyl donor can predictably modulate the strength of n→π* interactions, with data from model compounds, in solution in chloroform, in the solid state, and computationally. Herein, we examined whether the electronic properties of acyl capping groups could modulate the stability of PPII in peptides in water. In X-PPGY-NH2 peptides (X=10 acyl capping groups), the effect of acyl group identity on PPII was quantified by circular dichroism and NMR spectroscopy. Electron-rich acyl groups promoted PPII relative to the standard acetyl (Ac-) group, with the pivaloyl and iso-butyryl groups most significantly increasing PPII. In contrast, acyl derivatives with electron-withdrawing substituents and the formyl group relatively disfavored PPII. Similar results, though lesser in magnitude, were also observed in X-APPGY-NH2 peptides, indicating that the capping group can impact PPII conformation at both proline and non-proline residues. The pivaloyl group was particularly favorable in promoting PPII. The effects of acyl capping groups were further analyzed in X-DfpPGY-NH2 and X-ADfpPGY-NH2 peptides, Dfp=4,4-difluoroproline. Data on these peptides indicated that acyl groups induced order Piv- > Ac- > For-. These results suggest that greater consideration should be given to the identity of acyl capping groups in inducing structure in peptides.
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Affiliation(s)
- Megh R Bhatt
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, United States
| | - Neal J Zondlo
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, 19716, United States
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2
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Hansen TN, Olsen CA. Contemporary Applications of Thioamides and Methods for Their Synthesis. Chemistry 2024; 30:e202303770. [PMID: 38088462 DOI: 10.1002/chem.202303770] [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: 11/13/2023] [Indexed: 12/23/2023]
Abstract
Thioamides are naturally occurring isosteres of amide bonds in which the chalcogen atom of the carbonyl is changed from oxygen to sulfur. This substitution gives rise to altered nucleophilicity and hydrogen bonding properties with importance for both chemical reactivity and non-covalent interactions. As such, thioamides have been introduced into biologically active compounds to achieve improved target affinity and/or stability towards hydrolytic enzymes but have also been applied as probes of protein and peptide folding and dynamics. Recently, a series of new methods have been developed for the synthesis of thioamides as well as their utilization in peptide chemistry. Further, novel strategies for the incorporation of thioamides into proteins have been developed, enabling both structural and functional studies to be performed. In this Review, we highlight the recent developments in the preparation of thioamides and their applications for peptide modification and study of protein function.
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Affiliation(s)
- Tobias N Hansen
- Center for Biopharmaceuticals & Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
| | - Christian A Olsen
- Center for Biopharmaceuticals & Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100, Copenhagen, Denmark
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3
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Harris BS, Bejagam KK, Baer MD. Development of a Systematic and Extensible Force Field for Peptoids (STEPs). J Phys Chem B 2023; 127:6573-6584. [PMID: 37462325 DOI: 10.1021/acs.jpcb.3c01424] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Peptoids (N-substituted glycines) are a class of biomimetic polymers that have attracted significant attention due to their accessible synthesis and enzymatic and thermal stability relative to their naturally occurring counterparts (polypeptides). While these polymers provide the promise of more robust functional materials via hierarchical approaches, they present a new challenge for computational structure prediction for material design. The reliability of calculations hinges on the accuracy of interactions represented in the force field used to model peptoids. For proteins, structure prediction based on sequence and de novo design has made dramatic progress in recent years; however, these models are not readily transferable for peptoids. Current efforts to develop and implement peptoid-specific force fields are spread out, leading to replicated efforts and a fragmented collection of parameterized sidechains. Here, we developed a peptoid-specific force field containing 70 different side chains, using GAFF2 as starting point. The new model is validated based on the generation of Ramachandran-like plots from DFT optimization compared against force field reproduced potential energy and free energy surfaces as well as the reproduction of equilibrium cis/trans values for some residues experimentally known to form helical structures. Equilibrium cis/trans distributions (Kct) are estimated for all parameterized residues to identify which residues have an intrinsic propensity for cis or trans states in the monomeric state.
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Affiliation(s)
- Bradley S Harris
- Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Karteek K Bejagam
- Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Marcel D Baer
- Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
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4
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Rai Deka JK, Sahariah B, Sarma BK. Understanding the Cis-Trans Amide Bond Isomerization of N, N'-Diacylhydrazines to Develop Guidelines for A Priori Prediction of Their Most Stable Solution Conformers. J Org Chem 2023. [PMID: 36700530 DOI: 10.1021/acs.joc.2c01891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
N,N'-diacylhydrazines (R1CO-NR3-NR4-COR2) are a class of small molecules with a wide range of applications in chemistry and biology. They are structurally unique in the sense that their two amide groups are connected via a N-N single bond, and as a result, these molecules can exist in eight different isomeric forms. Four of these are amide isomers [trans-trans (t-t), trans-cis (t-c), cis-trans (c-t), and cis-cis (c-c)] arising from C-N bond restricted rotation. In addition, each of these amide isomers can exist in two different isomeric forms due to N-N bond restricted rotation, especially when R3 and R4 groups are relatively bigger. Herein, we have systematically investigated the conformations of 55 N,N'-diacylhydrazines using a combination of solution NMR spectroscopy, X-ray crystallography, and density functional theory calculations. Our data suggest that when the substituents R3 and R4 on the nitrogen atoms are both hydrogens. These molecules prefer twisted trans-trans (t-t) (>90%) geometries (H-N-C═O ∼ 180°), whereas the N-alkylated and N,N'-dialkylated molecules prefer twisted trans-cis (t-c) geometries. Herein, we have analyzed the stabilization of the various isomers of these molecules in light of steric and stereoelectronic effects. We provide a guideline to a priori predict the most stable conformers of the N,N'-diacylhydrazines just by examining their substituents (R1-R4).
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Affiliation(s)
- Jugal Kishore Rai Deka
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore 560064, India
| | - Biswajit Sahariah
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore 560064, India
| | - Bani Kanta Sarma
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore 560064, India
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5
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Kalita D, Sahariah B, Mookerjee SP, Sarma BK. Strategies to Control the cis-trans Isomerization of Peptoid Amide Bonds. Chem Asian J 2022; 17:e202200149. [PMID: 35362652 DOI: 10.1002/asia.202200149] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/30/2022] [Indexed: 11/11/2022]
Abstract
Peptoids are oligomers of N-substituted glycine units. They structurally resemble peptides but, unlike natural peptides, the side chains of peptoids are present on the amide nitrogen atoms instead of the α-carbons. The N-substitution improves cell-permeability of peptoids and enhance their proteolytic stability over natural peptides. Therefore, peptoids are ideal peptidomimetic candidates for drug discovery, especially for intracellular targets. Unfortunately, most peptoid ligands discovered so far possess moderate affinity towards their biological targets. The moderate affinity of peptoids for biomacromolecules is linked to their conformational flexibility, which causes substantial entropic loss during the peptoid-biomacromolecule binding process. The conformational flexibility of peptoids is caused by the lack of backbone chirality, absence of hydrogen bond donors (NH) in their backbone to form CO···HN hydrogen bonds and the facile cis-trans isomerization of their tertiary amide bonds. In recent years, many investigators have shown that the incorporation of specific side chains with unique steric and stereoelectronic features can favourably shift the cis-trans equilibria of peptoids towards one of the two isomeric forms. Such strategies are helpful to design homogenous peptoid oligomers having well defined secondary structures. Herein, we discuss the strategies developed over the years to control the cis-trans isomerization of peptoid amide bonds.
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Affiliation(s)
- Debajit Kalita
- Jawaharlal Nehru Centre for Advanced Scientific Research, New Chemistry Unit, INDIA
| | - Biswajit Sahariah
- Jawaharlal Nehru Centre for Advanced Scientific Research, New Chemistry Unit, INDIA
| | | | - Bani Kanta Sarma
- Jawaharlal Nehru Centre for Advanced Scientific Research, New Chemistry Unit, Rachenahalli Lake Road, Jakkur, 560064, India, 560064, Bangalore, INDIA
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6
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Herlan CN, Feser D, Schepers U, Bräse S. Bio-instructive materials on-demand - combinatorial chemistry of peptoids, foldamers, and beyond. Chem Commun (Camb) 2021; 57:11131-11152. [PMID: 34611672 DOI: 10.1039/d1cc04237h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Combinatorial chemistry allows for the rapid synthesis of large compound libraries for high throughput screenings in biology, medicinal chemistry, or materials science. Especially compounds from a highly modular design are interesting for the proper investigation of structure-to-activity relationships. Permutations of building blocks result in many similar but unique compounds. The influence of certain structural features on the entire structure can then be monitored and serve as a starting point for the rational design of potent molecules for various applications. Peptoids, a highly diverse class of bioinspired oligomers, suit perfectly for combinatorial chemistry. Their straightforward synthesis on a solid support using repetitive reaction steps ensures easy handling and high throughput. Applying this modular approach, peptoids are readily accessible, and their interchangeable side-chains allow for various structures. Thus, peptoids can easily be tuned in their solubility, their spatial structure, and, consequently, their applicability in various fields of research. Since their discovery, peptoids have been applied as antimicrobial agents, artificial membranes, molecular transporters, and much more. Studying their three-dimensional structure, various foldamers with fascinating, unique properties were discovered. This non-comprehensive review will state the most interesting discoveries made over the past years and arouse curiosity about what may come.
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Affiliation(s)
- Claudine Nicole Herlan
- Institute of Biological and Chemical Systems-Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology (KIT), Hermann von Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Dominik Feser
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann von Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Ute Schepers
- Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann von Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.,Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz Haber Weg 6, 76131 Karlsruhe, Germany
| | - Stefan Bräse
- Institute of Biological and Chemical Systems-Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology (KIT), Hermann von Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. .,Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz Haber Weg 6, 76131 Karlsruhe, Germany
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7
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Comeau C, Ries B, Stadelmann T, Tremblay J, Poulet S, Fröhlich U, Côté J, Boudreault PL, Derbali RM, Sarret P, Grandbois M, Leclair G, Riniker S, Marsault É. Modulation of the Passive Permeability of Semipeptidic Macrocycles: N- and C-Methylations Fine-Tune Conformation and Properties. J Med Chem 2021; 64:5365-5383. [PMID: 33750117 DOI: 10.1021/acs.jmedchem.0c02036] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Incorporating small modifications to peptidic macrocycles can have a major influence on their properties. For instance, N-methylation has been shown to impact permeability. A better understanding of the relationship between permeability and structure is of key importance as peptidic drugs are often associated with unfavorable pharmacokinetic profiles. Starting from a semipeptidic macrocycle backbone composed of a tripeptide tethered head-to-tail with an alkyl linker, we investigated two small changes: peptide-to-peptoid substitution and various methyl placements on the nonpeptidic linker. Implementing these changes in parallel, we created a collection of 36 compounds. Their permeability was then assessed in parallel artificial membrane permeability assay (PAMPA) and Caco-2 assays. Our results show a systematic improvement in permeability associated with one peptoid position in the cycle, while the influence of methyl substitution varies on a case-by-case basis. Using a combination of molecular dynamics simulations and NMR measurements, we offer hypotheses to explain such behavior.
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Affiliation(s)
- Christian Comeau
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
| | - Benjamin Ries
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Thomas Stadelmann
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Jacob Tremblay
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
| | - Sylvain Poulet
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
| | - Ulrike Fröhlich
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
| | - Jérôme Côté
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
| | - Pierre-Luc Boudreault
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
| | - Rabeb Mouna Derbali
- Faculté de pharmacie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Quebec, Canada H3C 3J7
| | - Philippe Sarret
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
| | - Michel Grandbois
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
| | - Grégoire Leclair
- Faculté de pharmacie, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Quebec, Canada H3C 3J7
| | - Sereina Riniker
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Éric Marsault
- Département de Pharmacologie-Physiologie, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, 3001, 12e av nord, Sherbrooke, Quebec, Canada J1H5N4
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8
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Wellhöfer I, Beck J, Frydenvang K, Bräse S, Olsen CA. Increasing the Functional Group Diversity in Helical β-Peptoids: Achievement of Solvent- and pH-Dependent Folding. J Org Chem 2020; 85:10466-10478. [PMID: 32806085 DOI: 10.1021/acs.joc.0c00780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We report the synthesis of a series of bis-functionalized β-peptoid oligomers of the hexamer length. This was achieved by synthesizing and incorporating protected amino- or azido-functionalized chiral building blocks into precursor oligomers by a trimer segment coupling strategy. The resulting hexamers were readily elaborated to provide target compounds displaying amino groups, carboxy groups, hydroxy groups, or triazolo-pyridines, which should enable metal ion binding. Analysis of the novel hexamers by circular dichroism (CD) spectroscopy and 1H-13C heteronuclear single quantum coherence nuclear magnetic resonance (HSQC NMR) spectroscopy revealed robust helical folding propensity in acetonitrile. CD analysis showed a solvent-dependent degree of helical content in the structural ensembles when adding different ratios of protic solvents including an aqueous buffer. These studies were enabled by a substantial increase in solubility compared to previously analyzed β-peptoid oligomers. This also allowed for the investigation of the effect of pH on the folding propensity of the amino- and carboxy-functionalized oligomers, respectively. Interestingly, we could show a reversible effect of sequentially adding acid and base, resulting in a switching between compositions of folded ensembles with varying helical content. We envision that the present discoveries can form the basis for the development of functional peptidomimetic materials responsive to external stimuli.
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Affiliation(s)
- Isabelle Wellhöfer
- Center for Biopharmaceuticals & Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
| | - Janina Beck
- Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany
| | - Karla Frydenvang
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
| | - Stefan Bräse
- Institute of Biological and Chemical Systems - Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, Eggenstein-Leopoldshafen D-76344, Germany.,Institute of Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany
| | - Christian A Olsen
- Center for Biopharmaceuticals & Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark
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9
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Reese HR, Shanahan CC, Proulx C, Menegatti S. Peptide science: A "rule model" for new generations of peptidomimetics. Acta Biomater 2020; 102:35-74. [PMID: 31698048 DOI: 10.1016/j.actbio.2019.10.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 10/17/2019] [Accepted: 10/30/2019] [Indexed: 02/07/2023]
Abstract
Peptides have been heavily investigated for their biocompatible and bioactive properties. Though a wide array of functionalities can be introduced by varying the amino acid sequence or by structural constraints, properties such as proteolytic stability, catalytic activity, and phase behavior in solution are difficult or impossible to impart upon naturally occurring α-L-peptides. To this end, sequence-controlled peptidomimetics exhibit new folds, morphologies, and chemical modifications that create new structures and functions. The study of these new classes of polymers, especially α-peptoids, has been highly influenced by the analysis, computational, and design techniques developed for peptides. This review examines techniques to determine primary, secondary, and tertiary structure of peptides, and how they have been adapted to investigate peptoid structure. Computational models developed for peptides have been modified to predict the morphologies of peptoids and have increased in accuracy in recent years. The combination of in vitro and in silico techniques have led to secondary and tertiary structure design principles that mirror those for peptides. We then examine several important developments in peptoid applications inspired by peptides such as pharmaceuticals, catalysis, and protein-binding. A brief survey of alternative backbone structures and research investigating these peptidomimetics shows how the advancement of peptide and peptoid science has influenced the growth of numerous fields of study. As peptide, peptoid, and other peptidomimetic studies continue to advance, we will expect to see higher throughput structural analyses, greater computational accuracy and functionality, and wider application space that can improve human health, solve environmental challenges, and meet industrial needs. STATEMENT OF SIGNIFICANCE: Many historical, chemical, and functional relations draw a thread connecting peptides to their recent cognates, the "peptidomimetics". This review presents a comprehensive survey of this field by highlighting the width and relevance of these familial connections. In the first section, we examine the experimental and computational techniques originally developed for peptides and their morphing into a broader analytical and predictive toolbox. The second section presents an excursus of the structures and properties of prominent peptidomimetics, and how the expansion of the chemical and structural diversity has returned new exciting properties. The third section presents an overview of technological applications and new families of peptidomimetics. As the field grows, new compounds emerge with clear potential in medicine and advanced manufacturing.
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10
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Zheng H, Ye H, Yu X, You L. Interplay between n→π* Interactions and Dynamic Covalent Bonds: Quantification and Modulation by Solvent Effects. J Am Chem Soc 2019; 141:8825-8833. [PMID: 31075197 DOI: 10.1021/jacs.9b01006] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Orbital donor-acceptor interactions play critical roles throughout chemistry, and hence, their regulation and functionalization are of great significance. Herein we demonstrate for the first time the investigation of n→π* interactions through the strategy of dynamic covalent chemistry (DCC), and we further showcase its use in the stabilization of imine. The n→π* interaction between donor X and acceptor aldehyde/imine within 2-X-2'-formylbiphenyl derivatives was found to significantly influence the thermodynamics of imine exchange. The orbital interaction was then quantified through imine exchange, the equilibrium of which was successfully correlated with the difference in natural bond orbital stabilization energy of n→π* interactions of aldehyde and its imine. Moreover, the examination of solvent effects provided insights into the distinct feature of the modulation of n→π* interaction with aprotic and protic solvents. The n→π* interaction involving imine was enhanced in protic solvents due to hydrogen bonding with the solvent. This finding further enabled the stabilization of imine in purely aqueous solution. The strategies and results reported should find application in many fields, including molecular recognition, biological labeling, and asymmetric catalysis.
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Affiliation(s)
- Hao Zheng
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter , Chinese Academy of Sciences , Fuzhou 350002 , China.,College of Chemistry and Material Science , Fujian Normal University , Fuzhou 350007 China
| | - Hebo Ye
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter , Chinese Academy of Sciences , Fuzhou 350002 , China.,University of Chinese of Academy of Sciences , Beijing 100049 , China
| | - Xiaoxia Yu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter , Chinese Academy of Sciences , Fuzhou 350002 , China.,College of Chemistry and Material Science , Fujian Normal University , Fuzhou 350007 China
| | - Lei You
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter , Chinese Academy of Sciences , Fuzhou 350002 , China.,University of Chinese of Academy of Sciences , Beijing 100049 , China
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11
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Wellhöfer I, Frydenvang K, Kotesova S, Christiansen AM, Laursen JS, Olsen CA. Functionalized Helical β-Peptoids. J Org Chem 2019; 84:3762-3779. [DOI: 10.1021/acs.joc.9b00218] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Isabelle Wellhöfer
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Karla Frydenvang
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Simona Kotesova
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Andreas M. Christiansen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Jonas S. Laursen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Christian A. Olsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
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12
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Spencer RK, Butterfoss GL, Edison JR, Eastwood JR, Whitelam S, Kirshenbaum K, Zuckermann RN. Stereochemistry of polypeptoid chain configurations. Biopolymers 2019; 110:e23266. [DOI: 10.1002/bip.23266] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/31/2019] [Accepted: 02/05/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Ryan K. Spencer
- Department of Chemistry University of California Irvine California
- Department of Chemical Engineering & Materials Science University of California Irvine California
| | - Glenn L. Butterfoss
- Center for Genomics and Systems Biology New York University Abu Dhabi Abu Dhabi United Arab Emirates
| | - John R. Edison
- Martin A Fisher School of Physics Brandeis University Waltham Massachusetts
- Molecular Foundry Lawrence Berkeley National Laboratory Berkeley California
| | | | - Stephen Whitelam
- Molecular Foundry Lawrence Berkeley National Laboratory Berkeley California
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13
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Mahanta N, Szantai-Kis DM, Petersson EJ, Mitchell DA. Biosynthesis and Chemical Applications of Thioamides. ACS Chem Biol 2019; 14:142-163. [PMID: 30698414 PMCID: PMC6404778 DOI: 10.1021/acschembio.8b01022] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Thioamidation as a posttranslational modification is exceptionally rare, with only a few reported natural products and exactly one known protein example (methyl-coenzyme M reductase from methane-metabolizing archaea). Recently, there has been significant progress in elucidating the biosynthesis and function of several thioamide-containing natural compounds. Separate developments in the chemical installation of thioamides into peptides and proteins have enabled cell biology and biophysical studies to advance the current understanding of natural thioamides. This review highlights the various strategies used by Nature to install thioamides in peptidic scaffolds and the potential functions of this rare but important modification. We also discuss synthetic methods used for the site-selective incorporation of thioamides into polypeptides with a brief discussion of the physicochemical implications. This account will serve as a foundation for the further study of thioamides in natural products and their various applications.
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Affiliation(s)
| | - D Miklos Szantai-Kis
- Department of Biochemistry and Molecular Biophysics, Perelman School of Medicine , University of Pennsylvania , 3700 Hamilton Walk , Philadelphia , Pennsylvania 19104 , United States
| | - E James Petersson
- Department of Biochemistry and Molecular Biophysics, Perelman School of Medicine , University of Pennsylvania , 3700 Hamilton Walk , Philadelphia , Pennsylvania 19104 , United States
- Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104 , United States
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14
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de la Torre AF, Ali A, Concepcion O, Montero-Alejo AL, Muñiz FM, Jiménez CA, Belmar J, Velázquez-Libera JL, Hernández-Rodríguez EW, Caballero J. A study of the cis–trans isomerization preference of N-alkylated peptides containing phosphorus in the side chain and backbone. NEW J CHEM 2019. [DOI: 10.1039/c9nj02234a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The current work provides a study on the cis–trans isomerization behaviour of N-alkylated peptides decorated with phosphonate ester groups.
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Affiliation(s)
- Alexander F. de la Torre
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | - Akbar Ali
- Department of Chemistry
- University of Sargodha
- Pakistan
| | - Odette Concepcion
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | | | - Francisco M. Muñiz
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | - Claudio A. Jiménez
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | - Julio Belmar
- Departamento de Química Orgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Concepción
- Chile
| | | | | | - Julio Caballero
- Centro de Bioinformática y Simulación Molecular (CBSM)
- Universidad de Talca
- Talca
- Chile
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15
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Zimnicka MM. Conformational Features of Thioamide-Containing Dipeptoids and Peptoid–Peptide Hybrids—Computational and Experimental Approaches. J Phys Chem A 2018; 122:7819-7831. [DOI: 10.1021/acs.jpca.8b05456] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Magdalena M. Zimnicka
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
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16
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Dumonteil G, Bhattacharjee N, Angelici G, Roy O, Faure S, Jouffret L, Jolibois F, Perrin L, Taillefumier C. Exploring the Conformation of Mixed Cis–Trans α,β-Oligopeptoids: A Joint Experimental and Computational Study. J Org Chem 2018; 83:6382-6396. [DOI: 10.1021/acs.joc.8b00606] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Geoffrey Dumonteil
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Nicholus Bhattacharjee
- Université de Toulouse-INSA-UPS, LPCNO, CNRS UMR 5215, 135 av Rangueil, F-31077, Toulouse, France
- Université de Lyon, Université Claude Bernard Lyon 1, CPE Lyon, INSA Lyon, ICBMS, CNRS UMR 5246, Equipe ITEMM, Bât Curien, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne, France
| | - Gaetano Angelici
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Olivier Roy
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Sophie Faure
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Laurent Jouffret
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
| | - Franck Jolibois
- Université de Toulouse-INSA-UPS, LPCNO, CNRS UMR 5215, 135 av Rangueil, F-31077, Toulouse, France
| | - Lionel Perrin
- Université de Lyon, Université Claude Bernard Lyon 1, CPE Lyon, INSA Lyon, ICBMS, CNRS UMR 5246, Equipe ITEMM, Bât Curien, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne, France
| | - Claude Taillefumier
- Université Clermont Auvergne, CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand, France
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17
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Soares P, Lucas X, Ciulli A. Thioamide substitution to probe the hydroxyproline recognition of VHL ligands. Bioorg Med Chem 2018; 26:2992-2995. [PMID: 29650462 PMCID: PMC6008493 DOI: 10.1016/j.bmc.2018.03.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 11/28/2022]
Abstract
Thioamide substitution influences hydrogen bond and n → π∗ interactions involved in the conformational stability of protein secondary structures and oligopeptides. Hydroxyproline is the key recognition element of small molecules targeting the von Hippel-Lindau (VHL) E3 ligase, which are of interest as probes of hypoxia signaling and ligands for PROTAC conjugation. We hypothesized that VHL ligands could be a privileged model system to evaluate the contribution of these interactions to protein:ligand complex formation. Herein we report the synthesis of VHL ligands bearing thioamide substitutions at the central hydroxyproline moiety, and characterize their binding by fluorescence polarization, isothermal titration calorimetry, X-ray crystallography and molecular modeling. In spite of a conserved binding mode, the substitution pattern had a pronounced impact on the ligand affinities. Together the results underscore the role of hydrogen bond and n → π∗ interactions in fine tuning hydroxyproline recognition by VHL.
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Affiliation(s)
- Pedro Soares
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK
| | - Xavier Lucas
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK
| | - Alessio Ciulli
- Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, UK.
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18
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Huang Y, Ferrie JJ, Chen X, Zhang Y, Szantai-Kis DM, Chenoweth DM, Petersson EJ. Electronic interactions of i, i + 1 dithioamides: increased fluorescence quenching and evidence for n-to-π* interactions. Chem Commun (Camb) 2018; 52:7798-801. [PMID: 27229876 DOI: 10.1039/c6cc00105j] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Thioamide residues can be effective, minimally-perturbing fluorescence quenching probes for studying protein folding and proteolysis. In order to increase the level of quenching, we have here explored the use of adjacent dithioamides. We have found that they are more effective fluorescence quenchers, as expected, but we have also observed unexpected changes in the thioamide absorption spectra that may arise from n-to-π* interactions of the thiocarbonyls. We have made use of the increased quenching to improve the fluorescence turn-on of thioamide protease sensors.
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Affiliation(s)
- Yun Huang
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA.
| | - John J Ferrie
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA.
| | - Xing Chen
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA.
| | - Yitao Zhang
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA.
| | - D Miklos Szantai-Kis
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA. and Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, Perelman School of Medicine, 3700 Hamilton Walk, Philadelphia, PA 19104, USA
| | - David M Chenoweth
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA.
| | - E James Petersson
- Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104, USA.
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Roy O, Dumonteil G, Faure S, Jouffret L, Kriznik A, Taillefumier C. Homogeneous and Robust Polyproline Type I Helices from Peptoids with Nonaromatic α-Chiral Side Chains. J Am Chem Soc 2017; 139:13533-13540. [PMID: 28837348 DOI: 10.1021/jacs.7b07475] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peptoids that are oligomers of N-substituted glycines represent a class of peptide mimics with great potential in areas ranging from medicinal chemistry to biomaterial science. Controlling the equilibria between the cis and trans conformations of their backbone amides is the major hurdle to overcome for the construction of discrete folded structures, particularly for the development of all-cis polyproline type I (PPI) helices, as tools for modulating biological functions. The prominent role of backbone to side chain electronic interactions (n → π*) and side chains bulkiness in promoting cis-amides was essentially investigated with peptoid aromatic side chains, among which the chiral 1-naphthylethyl (1npe) group yielded the best results. We have explored for the first time the possibility to achieve similar performances with a sterically hindered α-chiral aliphatic side chain. Herein, we report on the synthesis and detailed conformational analysis of a series of (S)-N-(1-tert-butylethyl)glycine (Ns1tbe) peptoid homo-oligomers. The X-ray crystal structure of an Ns1tbe pentamer revealed an all-cis PPI helix, and the CD curves of the Ns1tbe oligomers also resemble those of PPI peptide helices. Interestingly, the CD data reported here are the first for any conformationally homogeneous helical peptoids containing only α-chiral aliphatic side chains. Finally we also synthesized and analyzed two mixed oligomers composed of NtBu and Ns1tbe monomers. Strikingly, the solid state structure of the mixed oligomer Ac-(tBu)2-(s1tbe)4-(tBu)2-COOtBu, the longest to be solved for any linear peptoid, revealed a PPI helix of great regularity despite the presence of only 50% of chiral side chain in the sequence.
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Affiliation(s)
- Olivier Roy
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand , F-63000 Clermont-Ferrand, France
| | - Geoffrey Dumonteil
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand , F-63000 Clermont-Ferrand, France
| | - Sophie Faure
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand , F-63000 Clermont-Ferrand, France
| | - Laurent Jouffret
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand , F-63000 Clermont-Ferrand, France
| | - Alexandre Kriznik
- Université de Lorraine , Fédération de Recherche CNRS 3209, Service Commun de Biophysique Interactions Moléculaires, and Laboratoire Ingénierie Moléculaire et Physiopathologie Articulaire, CNRS, UMR 7365, BP 20199, F-54505 Vandoeuvre les Nancy, France
| | - Claude Taillefumier
- Université Clermont Auvergne, CNRS, SIGMA Clermont, Institut de Chimie de Clermont-Ferrand , F-63000 Clermont-Ferrand, France
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20
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Kitir B, Maolanon AR, Ohm RG, Colaço AR, Fristrup P, Madsen AS, Olsen CA. Chemical Editing of Macrocyclic Natural Products and Kinetic Profiling Reveal Slow, Tight-Binding Histone Deacetylase Inhibitors with Picomolar Affinities. Biochemistry 2017; 56:5134-5146. [DOI: 10.1021/acs.biochem.7b00725] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Betül Kitir
- Center
for Biopharmaceuticals and Department for Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Alex R. Maolanon
- Center
for Biopharmaceuticals and Department for Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Ragnhild G. Ohm
- Center
for Biopharmaceuticals and Department for Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Ana R. Colaço
- Department
of Chemistry, Technical University of Denmark, DK-2800 Kongens
Lyngby, Denmark
| | - Peter Fristrup
- Department
of Chemistry, Technical University of Denmark, DK-2800 Kongens
Lyngby, Denmark
| | - Andreas S. Madsen
- Center
for Biopharmaceuticals and Department for Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Christian A. Olsen
- Center
for Biopharmaceuticals and Department for Drug Design and Pharmacology,
Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
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21
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De Zotti M, Peggion C, Biondi B, Crisma M, Formaggio F, Toniolo C. Endothioxopeptides: A conformational overview. Biopolymers 2016; 106:697-713. [DOI: 10.1002/bip.22899] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/08/2016] [Accepted: 06/25/2016] [Indexed: 12/16/2022]
Affiliation(s)
- Marta De Zotti
- Department of Chemical Sciences; University of Padova; Padova 35131 Italy
| | - Cristina Peggion
- Department of Chemical Sciences; University of Padova; Padova 35131 Italy
| | - Barbara Biondi
- Institute of Biomolecular Chemistry, Padova Unit, CNR; Padova 35131 Italy
| | - Marco Crisma
- Institute of Biomolecular Chemistry, Padova Unit, CNR; Padova 35131 Italy
| | - Fernando Formaggio
- Department of Chemical Sciences; University of Padova; Padova 35131 Italy
- Institute of Biomolecular Chemistry, Padova Unit, CNR; Padova 35131 Italy
| | - Claudio Toniolo
- Department of Chemical Sciences; University of Padova; Padova 35131 Italy
- Institute of Biomolecular Chemistry, Padova Unit, CNR; Padova 35131 Italy
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22
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Gangloff N, Ulbricht J, Lorson T, Schlaad H, Luxenhofer R. Peptoids and Polypeptoids at the Frontier of Supra- and Macromolecular Engineering. Chem Rev 2015; 116:1753-802. [DOI: 10.1021/acs.chemrev.5b00201] [Citation(s) in RCA: 190] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Niklas Gangloff
- Functional Polymer
Materials, Chair for Chemical Technology of Materials Synthesis, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Juliane Ulbricht
- Functional Polymer
Materials, Chair for Chemical Technology of Materials Synthesis, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Thomas Lorson
- Functional Polymer
Materials, Chair for Chemical Technology of Materials Synthesis, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Helmut Schlaad
- Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
| | - Robert Luxenhofer
- Functional Polymer
Materials, Chair for Chemical Technology of Materials Synthesis, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
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Abstract
For a long time, peptides were considered unsuitable for drug development due to their inherently poor pharmacokinetic properties and proteolytic susceptibility. However, this paradigm has changed significantly in the past decade with the approval of numerous antibodies and proteins as drugs. In parallel, research in the field of synthetic molecules that are able to mimic or complement folding patterns exhibited by biopolymers, but are not recognized by proteases, have received considerable attention as well. Such entities were coined "foldamers" by Professor Gellman in an Account published in this journal in the late 1990s. Oligomers of N-alkylated 3-aminopropionic acid residues have been called β-peptoids due to their structural similarity to β-peptides and peptoids (N-alkylglycines), respectively. Because bona fide foldamer behavior has been demonstrated for both parent architectures, we wondered if the β-peptoids could serve as a successful addition to the known ensemble of peptidomimetic foldamers. When we entered this field, only the seminal description of libraries of β-peptoid dimers and trimers by Hamper et al. had been published a number of years earlier [ J. Org. Chem. 1998 , 63 , 708 ]. Perhaps somewhat naïvely in retrospect, we envisioned that elongation of chain length combined with introduction of bulky α-chiral side chains would deliver folded structures as reported for the α-peptoid counterparts. Initially, we, and others, were unsucessful in obtaining stable secondary structures of β-peptoid oligomers, and instead, these residues were either incorporated in cyclic structures or in combination with other types of residues to give peptidomimetic constructs with heterogeneous backbones. Amphiphilic architectures with various membrane-targeting activities, such as mimics of antimicrobial peptides or cell-penetrating peptides, have thus been particularly successful. Introduction of β-peptoid residues in histone deacetylase inhibitors mimicking nonribosomal cyclotetrapeptides have also been reported. In the present Account, we will sketch the scientific journey that ultimately delivered robustly folded β-peptoid oligomers. Contributions involving biological evaluation of peptidomimetic constructs containing β-peptoid residues, as mentioned above, which were investigated leading up to these recently reported high-resolution helical structures, will thus be discussed. On the basis of the work described in this Account, we envision that β-peptoids will find future utility as peptidomimetics for biomedical investigation containing both heterogeneous and homogeneous backbones. The recent demonstration of control over the secondary structure of a homogeneous β-peptoid backbone now enables structure-based design of scaffolds with predictable display of desired functionalities in three dimensions.
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Affiliation(s)
- Jonas S. Laursen
- Center for Biopharmaceuticals & Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark
| | - Jens Engel-Andreasen
- Center for Biopharmaceuticals & Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark
| | - Christian A. Olsen
- Center for Biopharmaceuticals & Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark
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