51
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Arrata I, Barnard A, Tomlinson DC, Wilson AJ. Interfacing native and non-native peptides: using Affimers to recognise α-helix mimicking foldamers. Chem Commun (Camb) 2018; 53:2834-2837. [PMID: 28217789 DOI: 10.1039/c6cc09395g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Selection methods are used to identify Affimers that recognise α-helix mimicking N-alkylated aromatic oligoamides thus demonstrating foldamer and natural α-amino acid codes are compatible.
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Affiliation(s)
- Irene Arrata
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. and Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Anna Barnard
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. and Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Darren C Tomlinson
- Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Andrew J Wilson
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. and Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
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52
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Dai W, Liu S, Zhang Z, Chi X, Cheng M, Du Y, Zhu Q. Conformational preferences and isomerization upon excitation/ionization of 2-methoxypyridine and 2-N-methylaminopyridine. Phys Chem Chem Phys 2018; 20:6211-6226. [PMID: 29431768 DOI: 10.1039/c7cp07854d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Conformers from the rotations of the methyl group and the methoxy or methylamino group, namely staggered (s)/eclipsed (e)-cis/trans 2-methoxypyridine (2MOP) and 2-N-methylaminopyridine (2NMP), are studied using theoretical calculations in combination with one-color resonance-enhanced two-photon ionization (1C-R2PI) and mass-analyzed threshold ionization (MATI) spectroscopies. The calculations predict that, for cis 2MOP, trans 2MOP and trans 2NMP, only the s conformers are stable in the S0, S1 and D0 states. However, for cis 2NMP, the stable conformer is staggered in the S0 state but eclipsed in the S1 and D0 states, indicating an isomerization upon the excitation or ionization from the S0 state. This is experimentally supported by the 1C-R2PI and MATI spectra of 2NMP. Due to the relative instability, the number density of trans 2MOP is too low in the sample to be detected. All the bands in the 1C-R2PI and MATI spectra of 2MOP are assigned to s-cis 2MOP. The energy differences between cis and trans conformers are derived from excitation and ionization energies, indicating another conformational isomerization: stable trans 2NMP in the S0 and S1 states but stable cis 2NMP in the D0 state. For 2MOP, the so-called syn preference previously found for the S0 state is also observed in the S1 and D0 states. The conformational preference and isomerization are discussed with natural bond orbital calculations and reduced density gradient analysis. For 2MOP, the syn preferences are mainly caused by the exchange repulsion among several σ-orbitals of the OCH3 group and the pyridine ring. While the relative stabilities of the s and e conformers of cis 2MOP and cis 2NMP are simultaneously influenced by steric repulsion and orbital interactions.
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Affiliation(s)
- Wenshuai Dai
- Beijing National Laboratory of Molecular Science, State Key laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
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53
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Roy A, Gautam A, Malla JA, Sarkar S, Mukherjee A, Talukdar P. Self-assembly of small-molecule fumaramides allows transmembrane chloride channel formation. Chem Commun (Camb) 2018; 54:2024-2027. [DOI: 10.1039/c7cc08693h] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Intermolecular hydrogen bonding of N1,N4-dicyclohexylfumaramide favors the formation of self-assembled ion channels, which facilitates selective Cl− transport across a lipid bilayer membrane.
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Affiliation(s)
- Arundhati Roy
- Department of Chemistry, Indian Institute of Science Education and Research Pune
- Pune 411008
- India
| | - Amitosh Gautam
- Department of Chemistry, Indian Institute of Science Education and Research Pune
- Pune 411008
- India
| | - Javid Ahmad Malla
- Department of Chemistry, Indian Institute of Science Education and Research Pune
- Pune 411008
- India
| | - Sohini Sarkar
- Department of Chemistry, Indian Institute of Science Education and Research Pune
- Pune 411008
- India
| | - Arnab Mukherjee
- Department of Chemistry, Indian Institute of Science Education and Research Pune
- Pune 411008
- India
| | - Pinaki Talukdar
- Department of Chemistry, Indian Institute of Science Education and Research Pune
- Pune 411008
- India
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54
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Lubbe AS, van Leeuwen T, Wezenberg SJ, Feringa BL. Designing dynamic functional molecular systems. Tetrahedron 2017. [DOI: 10.1016/j.tet.2017.06.049] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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55
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Greenfield JL, Rizzuto FJ, Goldberga I, Nitschke JR. Self-Assembly of Conjugated Metallopolymers with Tunable Length and Controlled Regiochemistry. Angew Chem Int Ed Engl 2017; 56:7541-7545. [PMID: 28470946 DOI: 10.1002/anie.201702320] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Indexed: 01/01/2023]
Abstract
Self-assembled materials can be designed to express useful optoelectronic properties; however, achieving structural control is a necessary precondition for the optimization of desired properties. Here we report a simple, metal-templated polymerization process that generates helical metallopolymer strands over 75 repeat units long (28 kDa) from a single bifunctional monomer and CuI . The resulting polymer consists of a double helix of two identical conjugated organic strands enclosing a central column of metal ions. The length of this metallopolymer can be controlled by adding monofunctional subcomponents to end-cap the conjugated ligands. The use of ditopic and bulky monotopic subcomponents, respectively, allows a head-to-head or head-to-tail double helix to be generated. Spectroscopic measurements of different polymer lengths demonstrate how control over polymer length leads to control over the electronic and luminescent properties of the resulting material, thereby enabling tunable white-light emission.
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Affiliation(s)
- Jake L Greenfield
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Felix J Rizzuto
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Ieva Goldberga
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Jonathan R Nitschke
- Chemistry Department, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
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56
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Greenfield JL, Rizzuto FJ, Goldberga I, Nitschke JR. Self-Assembly of Conjugated Metallopolymers with Tunable Length and Controlled Regiochemistry. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201702320] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Jake L. Greenfield
- Chemistry Department; University of Cambridge; Lensfield Road Cambridge CB2 1EW UK
| | - Felix J. Rizzuto
- Chemistry Department; University of Cambridge; Lensfield Road Cambridge CB2 1EW UK
| | - Ieva Goldberga
- Chemistry Department; University of Cambridge; Lensfield Road Cambridge CB2 1EW UK
| | - Jonathan R. Nitschke
- Chemistry Department; University of Cambridge; Lensfield Road Cambridge CB2 1EW UK
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57
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Tokoro Y, Ohtsuka N, Kusakabe A, Fukuzawa S. Helical Folding of Hydroxy‐Substituted N‐Hetero‐
ortho
‐phenylenes Directed by Intramolecular Hydrogen Bonds. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yuichiro Tokoro
- Department of Advanced Materials Chemistry Yokohama National University 79‐5 Tokiwadai, Hodogaya‐ku 240‐8501 Yokohama Japan
| | - Nobuhiko Ohtsuka
- Department of Applied Chemistry Institute of Science and Engineering Chuo University 1‐13‐27 Kasuga, Bunkyo‐ku 112‐8551 Tokyo Japan
| | - Akinori Kusakabe
- Department of Applied Chemistry Institute of Science and Engineering Chuo University 1‐13‐27 Kasuga, Bunkyo‐ku 112‐8551 Tokyo Japan
| | - Shin‐ichi Fukuzawa
- Department of Applied Chemistry Institute of Science and Engineering Chuo University 1‐13‐27 Kasuga, Bunkyo‐ku 112‐8551 Tokyo Japan
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58
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Misra R, Saseendran A, George G, Veeresh K, Raja KMP, Raghothama S, Hofmann HJ, Gopi HN. Structural Dimorphism of Achiral α,γ-Hybrid Peptide Foldamers: Coexistence of 12- and 15/17-Helices. Chemistry 2017; 23:3764-3772. [DOI: 10.1002/chem.201605753] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Indexed: 01/17/2023]
Affiliation(s)
- Rajkumar Misra
- Department of Chemistry; Indian Institution of Science Education and Research; Dr. Homi Bhabha Road Pune 411021 India
| | - Abhijith Saseendran
- Department of Chemistry; Indian Institution of Science Education and Research; Dr. Homi Bhabha Road Pune 411021 India
| | - Gijo George
- NMR Research Center; Indian Institute of Science; Bangalore 560012 India
| | - Kuruva Veeresh
- Department of Chemistry; Indian Institution of Science Education and Research; Dr. Homi Bhabha Road Pune 411021 India
| | - K. Muruga Poopathi Raja
- Department of Physical Chemistry; School of Chemistry; Madurai Kamaraj University; Madurai 625 021 India
| | | | - Hans-Jörg Hofmann
- Institute of Biochemistry; Faculty of Biosciences, Pharmacy and Psychology; Talstraße 33 04103 Leipzig Germany
| | - Hosahudya N. Gopi
- Department of Chemistry; Indian Institution of Science Education and Research; Dr. Homi Bhabha Road Pune 411021 India
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59
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Metrano A, Abascal NC, Mercado BQ, Paulson EK, Hurtley AE, Miller SJ. Diversity of Secondary Structure in Catalytic Peptides with β-Turn-Biased Sequences. J Am Chem Soc 2017; 139:492-516. [PMID: 28029251 PMCID: PMC5312972 DOI: 10.1021/jacs.6b11348] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Indexed: 11/30/2022]
Abstract
X-ray crystallography has been applied to the structural analysis of a series of tetrapeptides that were previously assessed for catalytic activity in an atroposelective bromination reaction. Common to the series is a central Pro-Xaa sequence, where Pro is either l- or d-proline, which was chosen to favor nucleation of canonical β-turn secondary structures. Crystallographic analysis of 35 different peptide sequences revealed a range of conformational states. The observed differences appear not only in cases where the Pro-Xaa loop-region is altered, but also when seemingly subtle alterations to the flanking residues are introduced. In many instances, distinct conformers of the same sequence were observed, either as symmetry-independent molecules within the same unit cell or as polymorphs. Computational studies using DFT provided additional insight into the analysis of solid-state structural features. Select X-ray crystal structures were compared to the corresponding solution structures derived from measured proton chemical shifts, 3J-values, and 1H-1H-NOESY contacts. These findings imply that the conformational space available to simple peptide-based catalysts is more diverse than precedent might suggest. The direct observation of multiple ground state conformations for peptides of this family, as well as the dynamic processes associated with conformational equilibria, underscore not only the challenge of designing peptide-based catalysts, but also the difficulty in predicting their accessible transition states. These findings implicate the advantages of low-barrier interconversions between conformations of peptide-based catalysts for multistep, enantioselective reactions.
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Affiliation(s)
- Anthony
J. Metrano
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Nadia C. Abascal
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Brandon Q. Mercado
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Eric K. Paulson
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Anna E. Hurtley
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
| | - Scott J. Miller
- Department of Chemistry, Yale University, P.O.
Box 208107, New Haven, Connecticut 06520-8107, United States
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60
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Diemer V, Maury J, Le Bailly BAF, Webb SJ, Clayden J. Dibenzazepinyl ureas as dual NMR and CD probes of helical screw-sense preference in conformationally equilibrating dynamic foldamers. Chem Commun (Camb) 2017; 53:10768-10771. [DOI: 10.1039/c7cc06427f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Dibenzazepinyl ureas act as probes to allow conformational analysis of screw-sense preference in dynamic foldamers by both NMR and CD spectroscopy.
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Affiliation(s)
- Vincent Diemer
- School of Chemistry
- University of Manchester
- Manchester M13 9PL
- UK
| | - Julien Maury
- School of Chemistry
- University of Manchester
- Manchester M13 9PL
- UK
| | | | - Simon J. Webb
- School of Chemistry
- University of Manchester
- Manchester M13 9PL
- UK
- Manchester Institute of Biotechnology
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61
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Mallo N, Brown PT, Iranmanesh H, MacDonald TSC, Teusner MJ, Harper JB, Ball GE, Beves JE. Photochromic switching behaviour of donor–acceptor Stenhouse adducts in organic solvents. Chem Commun (Camb) 2016; 52:13576-13579. [DOI: 10.1039/c6cc08079k] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We report photochromic donor–acceptor Stenhouse adducts (DASAs) capable of fully reversible photoisomerization with visible light in organic solvents including chloroform, acetonitrile and benzene.
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Affiliation(s)
- Neil Mallo
- School of Chemistry
- The University of New South Wales
- Kensington
- Australia
| | - Patrick T. Brown
- School of Chemistry
- The University of New South Wales
- Kensington
- Australia
| | - Hasti Iranmanesh
- School of Chemistry
- The University of New South Wales
- Kensington
- Australia
| | | | | | - Jason B. Harper
- School of Chemistry
- The University of New South Wales
- Kensington
- Australia
| | - Graham E. Ball
- School of Chemistry
- The University of New South Wales
- Kensington
- Australia
| | - Jonathon E. Beves
- School of Chemistry
- The University of New South Wales
- Kensington
- Australia
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