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Pahar S, Maayan G. An intramolecular cobalt-peptoid complex as an efficient electrocatalyst for water oxidation at low overpotential. Chem Sci 2024; 15:12928-12938. [PMID: 39148784 PMCID: PMC11323339 DOI: 10.1039/d4sc01182a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 07/05/2024] [Indexed: 08/17/2024] Open
Abstract
Water electrolysis is the simplest way to produce hydrogen, as a clean renewable fuel. However, the high overpotential and slow kinetics hamper its applicability. Designing efficient and stable electrocatalysts for water oxidation (WO), which is the first and limiting step of the water splitting process, can overcome this limitation. However, the development of such catalysts based on non-precious metal ions is still challenging. Herein we describe a bio-inspired Co(iii)-based complex i.e., a stable and efficient molecular electrocatalyst for WO, constructed from a peptidomimetic oligomer called peptoid - N-substituted glycine oligomer - bearing two binding ligands, terpyridine and bipyridine, and one ethanolic group as a proton shuttler. Upon binding of a cobalt ion, this peptoid forms an intramolecular Co(iii) complex, that acts as an efficient electrocatalyst for homogeneous WO in aqueous phosphate buffer at pH 7 with a high faradaic efficiency of up to 92% at an overpotential of about 430 mV, which is the lowest reported for Co-based homogeneous WO electrocatalysts to date. We demonstrated the high stability of the complex during electrocatalytic WO and that the ethanolic side chain plays a key role in the stability and activity of the complex and also in facilitating water binding, thus mimicking an enzymatic second coordination sphere.
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Affiliation(s)
- Suraj Pahar
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology Technion City Haifa 3200008 Israel
| | - Galia Maayan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology Technion City Haifa 3200008 Israel
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2
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Behar AE, Maayan G. The First Cu(I)-Peptoid Complex: Enabling Metal Ion Stability and Selectivity via Backbone Helicity. Chemistry 2023; 29:e202301118. [PMID: 37221918 DOI: 10.1002/chem.202301118] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 05/25/2023]
Abstract
Stabilization of Cu(I) is ubiquitous within native copper proteins. Understanding how to stabilize Cu(I) within synthetic biomimetic systems is therefore desired towards biological applications. Peptoids are an important class of peptodomimetics, that can bind metal ions and stabilize them in their high oxidation state. Thus, to date, they were not used for Cu(I) binding. Here we show how the helical peptoid hexamer, having two 2,2'-bipyridine (Bipy) groups that face the same side of the helix, forms the intramolecular air stable Cu(I) complex. Further study of the binding site by rigorous spectroscopic techniques suggests that Cu(I) is tetracoordinated, binding to only three N atoms from the Bipy ligands and to the N-terminus of the peptoid's backbone. A set of control peptoids and experiments indicates that the Cu(I) stability and selectivity are dictated by the intramolecular binding, forced by the helicity of the peptoid, which can be defined as the second coordination sphere of the metal center.
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Affiliation(s)
- Anastasia E Behar
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
| | - Galia Maayan
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, 3200008 Haifa, Israel
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3
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Ghosh P, Ruan G, Fridman N, Maayan G. Amide bond hydrolysis of peptoids. Chem Commun (Camb) 2022; 58:9922-9925. [PMID: 35979818 DOI: 10.1039/d2cc02717h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Incorporating a chiral non-coordinating substitution at the N-terminal end within peptoids facilitates regio-selective amide bond hydrolysis mediated by a transition metal ion and/or an acidic buffer as evident by X-ray crystallographic analysis, supported by ESI-MS. This opens up a new direction for peptidomimetic compounds towards future application in chemistry, biology and medicine.
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Affiliation(s)
- Pritam Ghosh
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel.
| | - Guilin Ruan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel.
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel.
| | - Galia Maayan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel.
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4
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Ruan G, Ghosh P, Fridman N, Maayan G. A Di-Copper-Peptoid in a Noninnocent Borate Buffer as a Fast Electrocatalyst for Homogeneous Water Oxidation with Low Overpotential. J Am Chem Soc 2021; 143:10614-10623. [PMID: 34237937 DOI: 10.1021/jacs.1c03225] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Water electrolysis is a promising approach toward low-cost renewable fuels; however, the high overpotential and slow kinetics limit its applicability. Studies suggest that either dinuclear copper (Cu) centers or the use of borate buffer can lead to efficient catalysis. We previously demonstrated the ability of peptoids-N-substituted glycine oligomers-to stabilize high-oxidation-state metal ions and to form self-assembled di-copper-peptoid complexes. Capitalizing on these features herein we report on a unique Cu-peptoid duplex, Cu2(BEE)2, that is a fast and stable homogeneous electrocatalyst for water oxidation in borate buffer at pH 9.35, with low overpotential and a high turnover frequency of 129 s-1 (peak current measurements) or 5503 s-1 (FOWA); both are the highest reported for Cu-based water electrocatalysts to date. BEE is a peptoid trimer having one 2,2'-bipyridine ligand and two ethanolic groups, easily synthesized on solid support. Cu2(BEE)2 was characterized by single-crystal X-ray diffraction and various spectroscopic and electrochemical techniques, demonstrating its ability to maintain stable in four cycles of controlled potential electrolysis, leading to a high overall turnover number of 51.4 in a total of 2 h. Interestingly, the catalytic activity of control complexes having only one ethanolic side chain is 2 orders of magnitude lower than that of Cu2(BEE)2. On the basis of this comparison and on mechanistic studies, we propose that the ethanolic side chains and the borate buffer have significant roles in the high stability and catalytic activity of Cu2(BEE)2; the -OH groups facilitate protons transfer, while the borate species enables oxygen transfer toward O-O bond formation.
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Affiliation(s)
- Guilin Ruan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Pritam Ghosh
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Galia Maayan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.,The Nancy and Stephen Grand Technion Energy Program, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
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5
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Fuller AA, Moreno JL, Nguyen MT. Using Fluorescence to Enable Innovative Functions of Foldamers. Isr J Chem 2021. [DOI: 10.1002/ijch.202000109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Amelia A. Fuller
- Department of Chemistry & Biochemistry Santa Clara University 500 El Camino Real Santa Clara CA 95053 USA
| | - Jose L. Moreno
- Department of Chemistry & Biochemistry Santa Clara University 500 El Camino Real Santa Clara CA 95053 USA
| | - Michelle T. Nguyen
- Department of Chemistry & Biochemistry Santa Clara University 500 El Camino Real Santa Clara CA 95053 USA
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6
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Ghosh P, Rozenberg I, Maayan G. Sequence-function relationship within water-soluble Peptoid Chelators for Cu 2. J Inorg Biochem 2021; 217:111388. [PMID: 33618230 DOI: 10.1016/j.jinorgbio.2021.111388] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/31/2021] [Accepted: 02/05/2021] [Indexed: 12/26/2022]
Abstract
Chelation of Cu2+ by synthetic molecules is an emerging therapeutic approach for treating several illnesses in human body such as Wilson disease, cancer and more. Among synthetic metal chelators, those based on peptoids - N-substituted glycine oligomers - are advantageous due to their structural similarity to peptides, ease of synthesis on solid support and versatile controlled sequences. Tuning peptoid sequences, via systematically changing at least one side chain, can facilitate and control their function. Along these lines, this work aims to explore the role of the non-coordinating side chain within peptoid chelators in order to understand the factors that control the selectivity of these chelators to Cu2+ in water medium. To this aim, a set of peptoid trimers having a pyridine group at the acetylated N-terminal, a 2,2'-bipyridine group at the second position and a non-coordinating group at the C-terminus, where the latter is systematically varied between aromatic, aliphatic, chiral or non-chiral, were investigated as selective chelators for Cu2+. The effect of the position of the non-coordinating group on the selectivity of the peptoid to Cu2+ was also tested. Based on extensive spectroscopic data, we found that the choice of the non-coordinating group along with its position dramatically influences the selectivity of the peptoids to Cu2+. We showed that peptoids having bulky chiral groups at the C-terminus enable high selectivity to Cu2+. We further demonstrated the ability of one of the selective chelators to remove Cu2+ from the natural copper binding protein metallothionein in HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) buffer medium.
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Affiliation(s)
- Pritam Ghosh
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel
| | - Ido Rozenberg
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel
| | - Galia Maayan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 3200008, Israel.
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Abstract
Sequence-defined oligomeric molecules with discrete folding propensities, termed foldamers, are a versatile source of agents with tailored structure and function. An inspiration for the development of the foldamer paradigm are natural biomacromolecules, the sequence-encoded folding of which is the basis of life. Metal ions and clusters are common features in proteins, where the role of metal varies from supporting structure to enabling function. The ubiquity of metals in natural systems suggests promise for metals in the context of folded artificial backbones. In this Minireview, we highlight efforts to realize this potential through a survey of published work on the design, synthesis, and characterization of metal-binding foldamers.
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Affiliation(s)
- Shilpa R Rao
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Shelby L Schettler
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - W Seth Horne
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, 15260, USA
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Ghosh P, Fridman N, Maayan G. From Distinct Metallopeptoids to Self‐Assembled Supramolecular Architectures. Chemistry 2020; 27:634-640. [DOI: 10.1002/chem.202003612] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/25/2020] [Indexed: 12/23/2022]
Affiliation(s)
- Pritam Ghosh
- Schulich Faculty of Chemistry Technion-Israel Institute of Technology Technion City Haifa 3200008 Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry Technion-Israel Institute of Technology Technion City Haifa 3200008 Israel
| | - Galia Maayan
- Schulich Faculty of Chemistry Technion-Israel Institute of Technology Technion City Haifa 3200008 Israel
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9
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Ghosh P, Maayan G. A rationally designed peptoid for the selective chelation of Zn 2+ over Cu 2. Chem Sci 2020; 11:10127-10134. [PMID: 34094275 PMCID: PMC8162371 DOI: 10.1039/d0sc03391j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The selective removal of Zn2+ from proteins by using a synthetic chelator is a promising therapeutic approach for the treatment of various diseases including cancer. Although the chelation of Zn2+ is well known, its removal from a protein in the presence of potential competing biologically relevant ions such as Cu2+ is hardly explored. Herein we present a peptoid - N-substituted glycine trimer - incorporating a picolyl group at the N-terminus, a non-coordinating but structurally directing benzyl group at the C-terminus and a 2,2':6',2''-terpyridine group in the second position, that selectively binds Zn2+ ions in the presence of excess Cu2+ ions in water. We further demonstrate that this chelator can selectively bind Zn2+ from a pool of excess biologically relevant and competitive ions (Cu2+, Fe3+, Ca2+, Mg2+, Na+, and K+) in a simulated body fluid (SBF), and also its ability to remove Zn2+ from a natural zinc protein domain (PYKCPECGKSFSQKSDLVKHQRTHTG) in a SBF.
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Affiliation(s)
- Pritam Ghosh
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology Technion City Haifa 3200008 Israel
| | - Galia Maayan
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology Technion City Haifa 3200008 Israel
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10
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Darapaneni CM, Ghosh P, Ghosh T, Maayan G. Unique β‐Turn Peptoid Structures and Their Application as Asymmetric Catalysts. Chemistry 2020; 26:9573-9579. [DOI: 10.1002/chem.202000595] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Indexed: 12/13/2022]
Affiliation(s)
| | - Pritam Ghosh
- Schulich Faculty of ChemistryTechnion-Israel Institute of Technology Haifa 3200008 Israel
| | - Totan Ghosh
- Schulich Faculty of ChemistryTechnion-Israel Institute of Technology Haifa 3200008 Israel
| | - Galia Maayan
- Schulich Faculty of ChemistryTechnion-Israel Institute of Technology Haifa 3200008 Israel
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11
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A Resin-Bound Peptoid as a Recyclable Heterogeneous Catalyst for Oxidation Reactions. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901739] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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12
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Rzeigui M, Traikia M, Jouffret L, Kriznik A, Khiari J, Roy O, Taillefumier C. Strengthening Peptoid Helicity through Sequence Site-Specific Positioning of Amide cis-Inducing NtBu Monomers. J Org Chem 2020; 85:2190-2201. [PMID: 31873018 DOI: 10.1021/acs.joc.9b02916] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The synthesis of biomimetic helical secondary structures is sought after for the construction of innovative nanomaterials and applications in medicinal chemistry such as the development of protein-protein interaction modulators. Peptoids, a sequence-defined family of oligomers, enable a peptidomimetic strategy, especially considering the easily accessible monomer diversity and peptoid helical folding propensity. However, cis-trans isomerization of the backbone tertiary amides may impair the peptoid's adoption of stable secondary structures, notably the all-cis polyproline I-like helical conformation. Here, we show that cis-inducing NtBu achiral monomers strategically positioned within chiral sequences may reinforce the degree of peptoid helicity, although with a reduced content of chiral side chains. The design principles presented here will undoubtedly help achieve more conformationally stable helical peptoids with desired functions.
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Affiliation(s)
- Maha Rzeigui
- Université Clermont Auvergne , CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand , France.,Université de Carthage , Faculté Des Sciences de Bizerte, Laboratoire de Chimie Organique et Analytique, ISEFC, 2000 Bardo , Tunisie
| | - Mounir Traikia
- 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
| | - Alexandre Kriznik
- Université de Lorraine , CNRS, IMoPA, F-54000 Nancy , France.,Université de Lorraine , CNRS, Inserm, UMS2008 IBSLor, Biophysics and Structural Biology Core Facility, F-54000 Nancy , France
| | - Jameleddine Khiari
- Université de Carthage , Faculté Des Sciences de Bizerte, Laboratoire de Chimie Organique et Analytique, ISEFC, 2000 Bardo , Tunisie
| | - Olivier Roy
- Université Clermont Auvergne , CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand , France
| | - Claude Taillefumier
- Université Clermont Auvergne , CNRS, SIGMA Clermont, ICCF, F-63000 Clermont-Ferrand , France
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