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Wang H, Caminati W, Li M, Chen J, Tian X, Grabow JU, Gou Q. n → π* Interaction Enabling Transient Inversion of Chirality. J Phys Chem Lett 2023; 14:8874-8879. [PMID: 37756497 DOI: 10.1021/acs.jpclett.3c02264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
This study reports the observation and characterization of two isomers of the acrolein dimer by using high-resolution rotational spectroscopy in pulsed jets. The first isomer is stabilized by two hydrogen bonds, adopting a planar configuration, and is energetically favored over the second isomer, which exhibits a dominant n → π* interaction in a nearly orthogonal arrangement. Surprisingly, the n → π* interaction was revealed to enable a concerted tunneling motion of two moieties along the carbonyl group. This motion leads to the inversion of transient chirality associated with the exchange of donor-acceptor roles, as revealed by the spectral feature of quadruplets. Inversion of transient chirality is a fundamental phenomenon in quantum mechanics and commonly observed for only inversional motions of protons. It is the first discovery, to the best of our knowledge, that such heavy moieties can also undergo chirality inversion.
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Affiliation(s)
- Hao Wang
- Department of Chemistry School of Chemistry and Chemical Engineering, Chongqing University, No. 55 Daxuecheng South Road Shapingba, Chongqing 401331, China
| | - Walther Caminati
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, Via Selmi 2, Bologna I-40126, Italy
| | - Meng Li
- Institut für Physikalische Chemie & Elektrochemie, Leibniz Universität Hannover, 30167 Hannover, Germany
| | - Junhua Chen
- School of Pharmacy, Guizhou Medical University, Guiyang 550025, Guizhou, China
| | - Xiao Tian
- Department of Chemistry School of Chemistry and Chemical Engineering, Chongqing University, No. 55 Daxuecheng South Road Shapingba, Chongqing 401331, China
| | - Jens-Uwe Grabow
- Institut für Physikalische Chemie & Elektrochemie, Leibniz Universität Hannover, 30167 Hannover, Germany
| | - Qian Gou
- Department of Chemistry School of Chemistry and Chemical Engineering, Chongqing University, No. 55 Daxuecheng South Road Shapingba, Chongqing 401331, China
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2
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Deka JKR, Borah D, Das P, Sahariah B, Vishnoi P, Sarma BK. Synergistic n → π* and n N → π* Ar interactions in C-terminal modified prolines: effect on Xaa-Pro cis/ trans equilibrium. Chem Commun (Camb) 2023; 59:6080-6083. [PMID: 37128689 DOI: 10.1039/d3cc01494k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Carbonyl-carbonyl (CO⋯CO) n → π* interaction often coexists with a hydrogen bond (HB) or another n → π* interaction. Although the interplay between HB and n → π* interaction was previously studied, there is no systematic investigation that shows a synergistic relationship of n → π* with another noncovalent interaction. Herein, we have studied a set of proline-diacylhydrazine (Pro-DAH) molecules and observed that increase in the strength of the nN → π*Ar interaction on their DAH side strengthened the n → π* interaction on the Pro side, which was experimentally determined by measuring the Ktrans/cis of the Xaa-Pro amide bond. Overall, we describe a simple C-terminal modification strategy to stabilize the trans-Pro geometry that could be useful to stabilize PPII helices and collagen triple helices that require Pro to adopt the trans amide geometry.
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Affiliation(s)
- Jugal Kishore Rai Deka
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064, India.
| | - Debashree Borah
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064, India.
| | - Paramesh Das
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064, India.
| | - Biswajit Sahariah
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064, India.
| | - Pratap Vishnoi
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064, India.
| | - Bani Kanta Sarma
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064, India.
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3
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Yin C, Lu H, Ye H, Feng Z, Zou H, Zhang M, You L. Double n→π* Interactions with One Electron Donor: Structural and Mechanistic Insights. Org Lett 2023; 25:1470-1475. [PMID: 36856609 DOI: 10.1021/acs.orglett.3c00205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Double n→π* interactions between one common electron donor of the carbonyl oxygen and two individual acceptor aldehyde/imine units are presented. The structural and mechanistic insights were revealed through a collection of experimental and computational evidence. The orientation and further energetic dependence of orbital interactions were facilely regulated by the size of cyclic urea scaffolds, the bulkiness of aldehydes/imines, and the flexibility of imine macrocycles.
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Affiliation(s)
- Chaowei Yin
- 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 Academy of Sciences, Beijing 100049, China
| | - Hanwei Lu
- 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 Academy of Sciences, Beijing 100049, 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
| | - Zelin Feng
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Hanxun Zou
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Meilan Zhang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, 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 Academy of Sciences, Beijing 100049, China
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4
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Li W, Xu Y, Jin Y, Li X, Caminati W, Feng G. Three non-bonding interaction topologies of the thiazole-formaldehyde complex observed by rotational spectroscopy. Phys Chem Chem Phys 2023; 25:6491-6497. [PMID: 36786009 DOI: 10.1039/d2cp05711e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
When an aldehyde molecule interacts with a nitrogen atom inserted in an aromatic ring, they form a number of non-bonding topologies. We measured the rotational spectra of three different isomers of the thiazole-formaldehyde adduct. In all of them, formaldehyde interacts specifically with thiazole through an n → π* interaction (along the Bürgi-Dunitz trajectory) and a C-H⋯O (acting as a proton acceptor) weak hydrogen bond, or through C-H⋯N (acting as a proton donor) and C-H⋯O (acting as a proton acceptor) weak hydrogen bonds. The spectra of isotopic substituted species were also measured to draw the molecular structures. Two n → π* stabilized isomers show a vertical structure in which the two molecular planes are perpendicular to each other, and the hydrogen bonded isomers feature a co-planar architecture. The competition between these non-bonding interactions was unveiled from experiments and theoretical calculations.
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Affiliation(s)
- Wenqin Li
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China. .,Departamento de Química Física y Química Inorganica, Facultad de Ciencias, Universidad de Valladolid, Valladolid E-47011, Spain
| | - Yugao Xu
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China.
| | - Yan Jin
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China.
| | - Xiaolong Li
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China.
| | - Walther Caminati
- Dipartimento di Chimica "G. Ciamician", Università di Bologna, Via Selmi 2, Bologna I-40126, Italy
| | - Gang Feng
- School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, 401331, Chongqing, China.
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Oznobikhina LP, Lazarev IM, Lazareva NF. Experimental and Theoretical Investigation of the Structure of Acetoacetanilide. RUSS J GEN CHEM+ 2022. [DOI: 10.1134/s1070363222110020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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6
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Purushotham M, Paul B, Govindachar DM, Singh AK, Periyasamy G, Peter SC. Ortho-halogen effects: n→π* interactions, halogen bonding, and deciphering chiral attributes in N-aryl glycine peptoid foldamers. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Zondlo NJ. Solvation stabilizes intercarbonyl n→π* interactions and polyproline II helix. Phys Chem Chem Phys 2022; 24:13571-13586. [PMID: 35635541 DOI: 10.1039/d2cp00857b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
n→π* interactions between consecutive carbonyls stabilize the α-helix and polyproline II helix (PPII) conformations in proteins. n→π* interactions have been suggested to provide significant conformational biases to the disordered states of proteins. To understand the roles of solvation on the strength of n→π* interactions, computational investigations were conducted on a model n→π* interaction, the twisted-parallel-offset formaldehyde dimer, as a function of explicit solvation of the donor and acceptor carbonyls, using water and HF. In addition, the effects of urea, thiourea, guanidinium, and monovalent cations on n→π* interaction strength were examined. Solvation of the acceptor carbonyl significantly strengthens the n→π* interaction, while solvation of the donor carbonyl only modestly weakens the n→π* interaction. The n→π* interaction strength was maximized with two solvent molecules on the acceptor carbonyl. Urea stabilized the n→π* interaction via simultaneous engagement of both oxygen lone pairs on the acceptor carbonyl. Solvent effects were further investigated in the model peptides Ac-Pro-NMe2, Ac-Ala-NMe2, and Ac-Pro2-NMe2. Solvent effects in peptides were similar to those in the formaldehyde dimer, with solvation of the acceptor carbonyl increasing n→π* interaction strength and resulting in more compact conformations, in both the proline endo and exo ring puckers, as well as a reduction in the energy difference between these ring puckers. Carbonyl solvation leads to an energetic preference for PPII over both the α-helix and β/extended conformations, consistent with experimental data that protic solvents and protein denaturants both promote PPII. Solvation of the acceptor carbonyl weakens the intraresidue C5 hydrogen bond that stabilizes the β conformation.
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Affiliation(s)
- Neal J Zondlo
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA.
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Szefczyk M, Szulc N, Gąsior-Głogowska M, Modrak-Wójcik A, Bzowska A, Majstrzyk W, Taube M, Kozak M, Gotszalk T, Rudzińska-Szostak E, Berlicki Ł. Hierarchical approach for the rational construction of helix-containing nanofibrils using α,β-peptides. NANOSCALE 2021; 13:4000-4015. [PMID: 33471005 DOI: 10.1039/d0nr04313c] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The rational design of novel self-assembled nanomaterials based on peptides remains a great challenge in modern chemistry. A hierarchical approach for the construction of nanofibrils based on α,β-peptide foldamers is proposed. The incorporation of a helix-promoting trans-(1S,2S)-2-aminocyclopentanecarboxylic acid residue in the outer positions of the model coiled-coil peptide led to its increased conformational stability, which was established consistently by the results of CD, NMR and FT-IR spectroscopy. The designed oligomerization state in the solution of the studied peptides was confirmed using analytical ultracentrifugation. Moreover, the cyclopentane side chain allowed additional interactions between coiled-coil-like structures to direct the self-assembly process towards the formation of well-defined nanofibrils, as observed using AFM and TEM techniques.
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Affiliation(s)
- Monika Szefczyk
- Department of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Natalia Szulc
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Marlena Gąsior-Głogowska
- Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Anna Modrak-Wójcik
- Division of Biophysics, Faculty of Physics, Institute of Experimental Physics, University of Warsaw, Ludwika Pasteura 5, 02-093 Warsaw, Poland
| | - Agnieszka Bzowska
- Division of Biophysics, Faculty of Physics, Institute of Experimental Physics, University of Warsaw, Ludwika Pasteura 5, 02-093 Warsaw, Poland
| | - Wojciech Majstrzyk
- Faculty of Microsystem Electronics and Photonics, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Michał Taube
- Department of Macromolecular Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
| | - Maciej Kozak
- Department of Macromolecular Physics, Adam Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Czerwone Maki 98, 30-392 Kraków, Poland
| | - Teodor Gotszalk
- Faculty of Microsystem Electronics and Photonics, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Ewa Rudzińska-Szostak
- Department of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
| | - Łukasz Berlicki
- Department of Bioorganic Chemistry, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
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Mohammed SJ, Salih AK, Rashid MAM, Omer KM, Abdalkarim KA. Synthesis, Spectroscopic Studies and Keto-Enol Tautomerism of Novel 1,3,4-Thiadiazole Derivative Containing 3-Mercaptobutan-2-one and Quinazolin-4-one Moieties. Molecules 2020; 25:molecules25225441. [PMID: 33233669 PMCID: PMC7699804 DOI: 10.3390/molecules25225441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 11/16/2022] Open
Abstract
In this study, a novel 1,3,4-thiadiazole derivative containing 3-mercaptobutan-2-one and quinazolin-4-one moieties (Compound 3) is synthesized by the coupling of 2-amino-1,3,4-thiadiazole-5-(3-mercaptobutan-2-one) (Compound 1) with 2-Phenyl-4H-3,1-benzoxazin-4-one (Compound 2) in one molecule moiety. Compound 3 is found to exist as two types of intra-molecular hydrogen bonding with keto-enol tautomerism characters, which is further confirmed using FTIR, 1H-NMR, 13C-NMR, mass spectrometer, and UV-Visible spectra. The 1H-NMR and UV-Visible spectra of Compound 3 are investigated in different solvents such as methanol, chloroform, and DMSO. Compound 3 exhibits keto-enol tautomeric forms in solvents with different percentage ratios depending on the solvent polarity. The 1H-NMR and UV-Visible spectral results show that Compound 3 favors the keto over the enol form in polar aprotic solvents such as DMSO and the enol over the keto form in non-polar solvents such as chloroform. The 13C-NMR spectrum gives two singles at δ 204.5 ppm, due to ketonic carbon, and δ 155.5 ppm, due to enolic carbon, confirming the keto-enol tautomerism of Compound 3. Furthermore, the molecular ion at m/z 43 and m/z 407 in the mass spectrum of Compound 3 and fragmentation mechanisms proposed reveal the existence of the keto and enol forms, respectively.
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Affiliation(s)
- Sewara J. Mohammed
- Department of Chemistry, College of Science, University of Sulaimani, Qlyasan Street, Kurdistan Regional Government, Sulaimani 46002, Iraq; (A.K.S.); (M.A.M.R.); (K.A.A.)
- Correspondence: (S.J.M.); (K.M.O.); Tel.: +964-770-193-2570 (S.J.M.); +964-770-505-6061 (K.M.O.)
| | - Akam K. Salih
- Department of Chemistry, College of Science, University of Sulaimani, Qlyasan Street, Kurdistan Regional Government, Sulaimani 46002, Iraq; (A.K.S.); (M.A.M.R.); (K.A.A.)
| | - Mohammad Amin M. Rashid
- Department of Chemistry, College of Science, University of Sulaimani, Qlyasan Street, Kurdistan Regional Government, Sulaimani 46002, Iraq; (A.K.S.); (M.A.M.R.); (K.A.A.)
| | - Khalid M. Omer
- Department of Chemistry, College of Science, University of Sulaimani, Qlyasan Street, Kurdistan Regional Government, Sulaimani 46002, Iraq; (A.K.S.); (M.A.M.R.); (K.A.A.)
- Komar Research Center (KRC), Komar University of Science and Technology, Kurdistan Regional Government, Sulaimani 46002, Iraq
- Correspondence: (S.J.M.); (K.M.O.); Tel.: +964-770-193-2570 (S.J.M.); +964-770-505-6061 (K.M.O.)
| | - Karzan A. Abdalkarim
- Department of Chemistry, College of Science, University of Sulaimani, Qlyasan Street, Kurdistan Regional Government, Sulaimani 46002, Iraq; (A.K.S.); (M.A.M.R.); (K.A.A.)
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10
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Xu X, He F, Yang W, Yao J. Effect of Homochirality of Dipeptide to Polymers’ Degradation. Polymers (Basel) 2020; 12:polym12092164. [PMID: 32971890 PMCID: PMC7570312 DOI: 10.3390/polym12092164] [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: 08/31/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 11/16/2022] Open
Abstract
As natural polymer materials, proteins are readily biodegradable, interestingly, the synthetic polyamides (PAs) that are based on the same amide bonds (also called peptide bonds in proteins) are barely degradable. Whether did the chirality and configuration of the amino acids play an important role. By using different configuration of amino acids, 4 types of polyamide-imides (PAIs) containing dipeptides of LL, DL, LD, and DD configurations, respectively, were synthesized. It was found that the PAIs based on natural LL configuration of dipeptide structure are much more readily biodegradable than those based on non-natural LD, DL, and DD configuration of dipeptides. It was confirmed that the natural L-configuration of amino acids play a critical role in degradability of proteins. And it also suggested that different type and amount of peptide fragments can be introduced in polymer to create series of polymer materials that can be biodegraded at controllable speed.
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Affiliation(s)
- Xinqiang Xu
- School of Materials Science & Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.X.); (F.H.); (W.Y.)
- Shandong Provincial Key Laboratory of Processing & Testing Technology of Glass and Functional Ceramics, Jinan 250353, China
| | - Fuyan He
- School of Materials Science & Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.X.); (F.H.); (W.Y.)
- Shandong Provincial Key Laboratory of Processing & Testing Technology of Glass and Functional Ceramics, Jinan 250353, China
| | - Wenke Yang
- School of Materials Science & Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.X.); (F.H.); (W.Y.)
- Shandong Provincial Key Laboratory of Processing & Testing Technology of Glass and Functional Ceramics, Jinan 250353, China
| | - Jinshui Yao
- School of Materials Science & Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.X.); (F.H.); (W.Y.)
- Shandong Provincial Key Laboratory of Processing & Testing Technology of Glass and Functional Ceramics, Jinan 250353, China
- Correspondence:
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11
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Yang TQ, Peng B, Shan BQ, Zong YX, Jiang JG, Wu P, Zhang K. Origin of the Photoluminescence of Metal Nanoclusters: From Metal-Centered Emission to Ligand-Centered Emission. NANOMATERIALS 2020; 10:nano10020261. [PMID: 32033058 PMCID: PMC7075164 DOI: 10.3390/nano10020261] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/26/2020] [Accepted: 01/29/2020] [Indexed: 12/17/2022]
Abstract
Recently, metal nanoclusters (MNCs) emerged as a new class of luminescent materials and have attracted tremendous interest in the area of luminescence-related applications due to their excellent luminous properties (good photostability, large Stokes shift) and inherent good biocompatibility. However, the origin of photoluminescence (PL) of MNCs is still not fully understood, which has limited their practical application. In this mini-review, focusing on the origin of the photoemission emission of MNCs, we simply review the evolution of luminescent mechanism models of MNCs, from the pure metal-centered quantum confinement mechanics to ligand-centered p band intermediate state (PBIS) model via a transitional ligand-to-metal charge transfer (LMCT or LMMCT) mechanism as a compromise model.
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Affiliation(s)
| | | | | | | | | | - Peng Wu
- Correspondence: (P.W.); (K.Z.)
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12
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The effect of a double n(O) → π∗(C = O) intramolecular interaction on the stability of 3-nitrophthalic acid. Struct Chem 2020. [DOI: 10.1007/s11224-019-01399-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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13
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Singh SK, Panwaria P, Mishra KK, Das A. Steric as well as n→π* Interaction Controls the Conformational Preferences of Phenyl Acetate: Gas‐phase Spectroscopy and Quantum Chemical Calculations. Chem Asian J 2019; 14:4705-4711. [DOI: 10.1002/asia.201901158] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 09/03/2019] [Indexed: 01/26/2023]
Affiliation(s)
- Santosh K. Singh
- Department of ChemistryIndian Institute of Science Education and Research (IISER) Pune Dr. Homi Bhabha Road Pashan, Pune- 411008 India
- Current Address: Department of ChemistryUniversity of Hawaii, Manoa Honolulu Hawaii 96822 USA
| | - Prakash Panwaria
- Department of ChemistryIndian Institute of Science Education and Research (IISER) Pune Dr. Homi Bhabha Road Pashan, Pune- 411008 India
| | - Kamal K. Mishra
- Department of ChemistryIndian Institute of Science Education and Research (IISER) Pune Dr. Homi Bhabha Road Pashan, Pune- 411008 India
| | - Aloke Das
- Department of ChemistryIndian Institute of Science Education and Research (IISER) Pune Dr. Homi Bhabha Road Pashan, Pune- 411008 India
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14
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Abstract
A complete inventory of the forces governing protein folding is critical for productive protein modeling, including structure prediction and de novo design, as well as understanding protein misfolding diseases of clinical significance. The dominant contributors to protein folding include the hydrophobic effect and conventional hydrogen bonding, along with Coulombic and van der Waals interactions. Over the past few decades, important additional contributors have been identified, including C-H···O hydrogen bonding, n→π* interactions, C5 hydrogen bonding, chalcogen bonding, and interactions involving aromatic rings (cation-π, X-H···π, π-π, anion-π, and sulfur-arene). These secondary contributions fall into two general classes: (1) weak but abundant interactions of the protein main chain and (2) strong but less frequent interactions involving protein side chains. Though interactions with high individual energies play important roles in specifying nonlocal molecular contacts and ligand binding, we estimate that weak but abundant interactions are likely to make greater overall contributions to protein folding, particularly at the level of secondary structure. Further research is likely to illuminate additional roles of these noncanonical interactions and could also reveal contributions yet unknown.
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Affiliation(s)
| | - Ronald T. Raines
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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15
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Aliev AE, Motherwell WB. Some Recent Advances in the Design and Use of Molecular Balances for the Experimental Quantification of Intramolecular Noncovalent Interactions of π Systems. Chemistry 2019; 25:10516-10530. [DOI: 10.1002/chem.201900854] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 05/09/2019] [Indexed: 02/03/2023]
Affiliation(s)
- Abil E. Aliev
- Department of ChemistryUniversity College London 20 Gordon Street London WC1H 0AJ UK
| | - William B. Motherwell
- Department of ChemistryUniversity College London 20 Gordon Street London WC1H 0AJ UK
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16
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Agouridas V, El Mahdi O, Diemer V, Cargoët M, Monbaliu JCM, Melnyk O. Native Chemical Ligation and Extended Methods: Mechanisms, Catalysis, Scope, and Limitations. Chem Rev 2019; 119:7328-7443. [DOI: 10.1021/acs.chemrev.8b00712] [Citation(s) in RCA: 243] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Vangelis Agouridas
- UMR CNRS 8204, Centre d’Immunité et d’Infection de Lille, University of Lille, CNRS, Institut Pasteur de Lille, F-59000 Lille, France
| | - Ouafâa El Mahdi
- Faculté Polydisciplinaire de Taza, University Sidi Mohamed Ben Abdellah, BP 1223 Taza Gare, Morocco
| | - Vincent Diemer
- UMR CNRS 8204, Centre d’Immunité et d’Infection de Lille, University of Lille, CNRS, Institut Pasteur de Lille, F-59000 Lille, France
| | - Marine Cargoët
- UMR CNRS 8204, Centre d’Immunité et d’Infection de Lille, University of Lille, CNRS, Institut Pasteur de Lille, F-59000 Lille, France
| | - Jean-Christophe M. Monbaliu
- Center for Integrated Technology and Organic Synthesis, Department of Chemistry, University of Liège, Building B6a, Room 3/16a, Sart-Tilman, B-4000 Liège, Belgium
| | - Oleg Melnyk
- UMR CNRS 8204, Centre d’Immunité et d’Infection de Lille, University of Lille, CNRS, Institut Pasteur de Lille, F-59000 Lille, France
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17
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Malde AK, Hill TA, Iyer A, Fairlie DP. Crystal Structures of Protein-Bound Cyclic Peptides. Chem Rev 2019; 119:9861-9914. [DOI: 10.1021/acs.chemrev.8b00807] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Alpeshkumar K. Malde
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Timothy A. Hill
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Abishek Iyer
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - David P. Fairlie
- Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
- Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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18
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Etzkorn FA, Ware RI, Pester AM, Troya D. Conformational Analysis of n→π* Interactions in Collagen Triple Helix Models. J Phys Chem B 2019; 123:496-503. [PMID: 30525631 DOI: 10.1021/acs.jpcb.8b08384] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ab initio calculations of three models of collagen at positions Pro-Pro-Gly (1), Pro-Gly-Pro (2), and Gly-Pro-Pro (3) were performed to assess the conformational variation of n→π* contributions to the stability of the collagen triple helix. Full conformational analyses by relaxed potential-energy scans of the Ψ dihedral angle of the central residue in models 1, 2, and 3 revealed the presence of several n→π* interactions. In model 2, with Gly as the central residue, both the Φ and Ψ dihedral angles of Gly were scanned. Most minima of each model contained one or two n→π* interactions, with pyramidalization at the π* carbon. We also observed pyramidalization at the n→π* donor amide nitrogens. Minima with hydrogen-bond or non-native n→π* interactions compete with the collagen stabilizing n→π* interactions. The collagen-like n→ re-π* conformation was found as the global minimum only in model 3. The global minimum of 1 had a 5-membered ring hydrogen bond with an additional weak n→ si-π* interaction. The global minimum of 2 was in the extended conformation. We predict that the n→π* interactions found in native collagen, while individually small, cumulatively contribute to the stability of the triple helix conformation of collagen.
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Affiliation(s)
- Felicia A Etzkorn
- Department of Chemistry , Virginia Tech , Blacksburg Virginia 24061 , United States
| | - Rachel I Ware
- Department of Chemistry , Virginia Tech , Blacksburg Virginia 24061 , United States
| | - Amanda M Pester
- Department of Chemistry , Virginia Tech , Blacksburg Virginia 24061 , United States
| | - Diego Troya
- Department of Chemistry , Virginia Tech , Blacksburg Virginia 24061 , United States
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19
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Bristow JC, Addicoat MA, Wallis JD. O(−)⋯C interactions and bond formation in 1-naphtholate anions with peri-located electrophilic carbon centres. CrystEngComm 2019. [DOI: 10.1039/c8ce01872c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
n–π* interactions between naphtholate O anions and carbonyl groups are determined to be shorter than in corresponding naphthols by X-ray crystallography, and lead to cyclisations with long O–C bonds when the carbonyl group is replaced by a strongly electron deficient alkene.
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Affiliation(s)
- Jonathan C. Bristow
- School of Science and Technology
- Nottingham Trent University
- Nottingham NG11 8NS
- UK
| | - Matthew A. Addicoat
- School of Science and Technology
- Nottingham Trent University
- Nottingham NG11 8NS
- UK
| | - John D. Wallis
- School of Science and Technology
- Nottingham Trent University
- Nottingham NG11 8NS
- UK
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20
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Deb P, Jin GY, Singh SK, Moon J, Kwon H, Das A, Bagchi S, Kim YS. Interconverting Hydrogen-Bonding and Weak n → π* Interactions in Aqueous Solution: A Direct Spectroscopic Evidence. J Phys Chem Lett 2018; 9:5425-5429. [PMID: 30149713 DOI: 10.1021/acs.jpclett.8b02398] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Molecular structure and function depend on myriad noncovalent interactions. However, the weak and transient nature of noncovalent interactions in solution makes them challenging to study. Information on weak interactions is typically derived from theory and indirect structural data. Solvent fluctuations, not revealed by structure analysis, further complicate the study of these interactions. Using 2D infrared spectroscopy, we show that the strong hydrogen bond and the weak n → π* interaction coexist and interconvert in aqueous solution. We found that the kinetics of these interconverting interactions becomes faster with increasing water content. This experimental observation provides a new perspective on the existence of weak noncovalent interactions in aqueous solution.
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Affiliation(s)
- Pranab Deb
- Physical and Materials Chemistry Division , CSIR-National Chemical Laboratory (CSIR-NCL) , Dr. Homi Bhabha Road , Pune 411008 , India
- Academy of Scientific & Innovative Research (AcSIR) , CSIR-National Chemical Laboratory (CSIR-NCL) , Dr. Homi Bhabha Road , Pune 411008 , India
| | - Geun Young Jin
- Department of Chemistry , Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil , Ulsan 44919 , Republic of Korea
- Department of NanoFusion Technology , Pusan National University , Busan 46241 , Republic of Korea
| | - Santosh K Singh
- Department of Chemistry , Indian Institute of Science Education and Research (IISER) , Dr. Homi Bhabha Road , Pune 411008 , India
| | - Juran Moon
- Department of Chemistry , Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil , Ulsan 44919 , Republic of Korea
| | - Hyejin Kwon
- Department of Chemistry , Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil , Ulsan 44919 , Republic of Korea
| | - Aloke Das
- Department of Chemistry , Indian Institute of Science Education and Research (IISER) , Dr. Homi Bhabha Road , Pune 411008 , India
| | - Sayan Bagchi
- Physical and Materials Chemistry Division , CSIR-National Chemical Laboratory (CSIR-NCL) , Dr. Homi Bhabha Road , Pune 411008 , India
- Academy of Scientific & Innovative Research (AcSIR) , CSIR-National Chemical Laboratory (CSIR-NCL) , Dr. Homi Bhabha Road , Pune 411008 , India
| | - Yung Sam Kim
- Department of Chemistry , Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil , Ulsan 44919 , Republic of Korea
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21
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Echeverría J. Intermolecular Carbonyl···Carbonyl Interactions in Transition-Metal Complexes. Inorg Chem 2018; 57:5429-5437. [PMID: 29664621 DOI: 10.1021/acs.inorgchem.8b00392] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We performed a comprehensive analysis of intermolecular carbonyl-carbonyl interactions in transition-metal complexes. Those interactions can be classified in two main types depending on the organometallic or organic nature of the donor carbonyl: M-CO···CO and R-CO···CO, respectively. By means of a combined structural and computational study we unraveled their geometrical features and strength. Moreover, electronic structure, natural bond orbitals, energy decomposition analysis, and quantum theory of atoms in molecules calculations were performed to try to understand their nature. Remarkably, we discovered that these carbonyl-carbonyl contacts have several features of the n → π* interaction. The charge transfer from an oxygen lone pair to an empty antibonding π orbital of the acceptor carbonyl is also accompanied by an electrostatic Oδ-···Cδ+ interaction. To the best of our knowledge this is the first report of an intermolecular n → π* interaction in metal complexes. These results might be significant, for instance, for the catalytic activation of carbonyl-containing small molecules with metal compounds or in the design of hybrid organic-inorganic materials, metal-organic frameworks, and other extended structures.
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Affiliation(s)
- Jorge Echeverría
- Departament de Química Inorgànica i Orgànica and Institut de Química Teòrica i Computacional IQTC-UB , Universitat de Barcelona , Martí i Franquès 1-11 , 08028 Barcelona , Spain
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22
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Pascoe DJ, Ling KB, Cockroft SL. The Origin of Chalcogen-Bonding Interactions. J Am Chem Soc 2017; 139:15160-15167. [PMID: 28985065 DOI: 10.1021/jacs.7b08511] [Citation(s) in RCA: 339] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Favorable molecular interactions between group 16 elements have been implicated in catalysis, biological processes, and materials and medicinal chemistry. Such interactions have since become known as chalcogen bonds by analogy to hydrogen and halogen bonds. Although the prevalence and applications of chalcogen-bonding interactions continues to develop, debate still surrounds the energetic significance and physicochemical origins of this class of σ-hole interaction. Here, synthetic molecular balances were used to perform a quantitative experimental investigation of chalcogen-bonding interactions. Over 160 experimental conformational free energies were measured in 13 different solvents to examine the energetics of O···S, O···Se, S···S, O···HC, and S···HC contacts and the associated substituent and solvent effects. The strongest chalcogen-bonding interactions were found to be at least as strong as conventional H-bonds, but unlike H-bonds, surprisingly independent of the solvent. The independence of the conformational free energies on solvent polarity, polarizability, and H-bonding characteristics showed that electrostatic, solvophobic, and van der Waals dispersion forces did not account for the observed experimental trends. Instead, a quantitative relationship between the experimental conformational free energies and computed molecular orbital energies was consistent with the chalcogen-bonding interactions being dominated by n → σ* orbital delocalization between a lone pair (n) of a (thio)amide donor and the antibonding σ* orbital of an acceptor thiophene or selenophene. Interestingly, stabilization was manifested through the same acceptor molecular orbital irrespective of whether a direct chalcogen···chalcogen or chalcogen···H-C contact was made. Our results underline the importance of often-overlooked orbital delocalization effects in conformational control and molecular recognition phenomena.
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Affiliation(s)
- Dominic J Pascoe
- EaStCHEM School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K
| | - Kenneth B Ling
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, U.K
| | - Scott L Cockroft
- EaStCHEM School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, U.K
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23
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Yang T, Dai S, Yang S, Chen L, Liu P, Dong K, Zhou J, Chen Y, Pan H, Zhang S, Chen J, Zhang K, Wu P, Xu J. Interfacial Clustering-Triggered Fluorescence-Phosphorescence Dual Solvoluminescence of Metal Nanoclusters. J Phys Chem Lett 2017; 8:3980-3985. [PMID: 28792774 DOI: 10.1021/acs.jpclett.7b01736] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The fluorescence-phosphorescence dual solvoluminescence (SL) of water-soluble metal nanoclusters (NCs) at room temperature was successfully achieved by a simple solvent-stimulated strategy. The strong interaction between carboxylate ligands and the metal core at the nanoscale interface not only induces rigid conformations of carbonyl groups but also affords a perfect carbonyl cluster that acts as an exact chromophore of metal NCs for aggregation-induced emission (AIE) mechanics. The clustering of carbonyl groups bearing on the polymer backbone chain is promoted by newly discovered n → π* noncovalent interactions. The efficient delocalization of electrons in overlapped C═O double bonds between neighboring carbonyl groups triggered by strong n → π* interactions in the polymer cluster accounts for its unique SL properties, especially the abnormal phosphorescence. This was further confirmed by controlled experiments for the presence of intersystem crossing (ISC) transitions. The results provide novel insights for understanding the complex SL process and open up a new way to study the inherent mechanism of SL by broadening the application of metal NCs.
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Affiliation(s)
- Taiqun Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Shan Dai
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Songqiu Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, People's Republic of China
| | - Li Chen
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Pengcheng Liu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Kailong Dong
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Jiasheng Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Yuting Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Haifeng Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Sanjun Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
- Collaborative Innovation Center of Extreme Optics, Shanxi University , Taiyuan, Shanxi 030006, People's Republic of China
- NYU-ECNU Institute of Physics at NYU Shanghai , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Jinquan Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Kun Zhang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Peng Wu
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
| | - Jianhua Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University , No. 3663, North Zhongshan Road, Shanghai 200062, People's Republic of China
- Collaborative Innovation Center of Extreme Optics, Shanxi University , Taiyuan, Shanxi 030006, People's Republic of China
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24
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Torshin IY, Batyanovskii AV, Uroshlev LA, Esipova NG, Tumanyan VG. The relationship between the sign of the polypeptide backbone angle omega and the type of the side chain radical of amino-acid residues. Biophysics (Nagoya-shi) 2017. [DOI: 10.1134/s0006350917030216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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25
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Abstract
The carbonyl group holds a prominent position in chemistry and biology not only because it allows diverse transformations but also because it supports key intermolecular interactions, including hydrogen bonding. More recently, carbonyl groups have been found to interact with a variety of nucleophiles, including other carbonyl groups, in what we have termed an n→π* interaction. In an n→π* interaction, a nucleophile donates lone-pair (n) electron density into the empty π* orbital of a nearby carbonyl group. Mixing of these orbitals releases energy, resulting in an attractive interaction. Hints of such interactions were evident in small-molecule crystal structures as early as the 1970s, but not until 2001 was the role of such interactions articulated clearly. These non-covalent interactions were first discovered during investigations into the thermostability of the proline-rich protein collagen, which achieves a robust structure despite a relatively low potential for hydrogen bonding. It was found that by modulating the distance between two carbonyl groups in the peptide backbone, one could alter the conformational preferences of a peptide bond to proline. Specifically, only the trans conformation of a peptide bond to proline allows for an attractive interaction with an adjacent carbonyl group, so when one increases the proximity of the two carbonyl groups, one enhances their interaction and promotes the trans conformation of the peptide bond, which increases the thermostability of collagen. More recently, attention has been paid to the nature of these interactions. Some have argued that rather than resulting from electron donation, carbonyl interactions are a particular example of dipolar interactions that are well-approximated by classical mechanics. However, experimental evidence has demonstrated otherwise. Numerous examples now exist where an increase in the dipole moment of a carbonyl group decreases the strength of its interactions with other carbonyl groups, demonstrating unequivocally that a dipolar mechanism is insufficient to describe these interactions. Rather, these interactions have important quantum-mechanical character that can be evaluated through careful experimental analysis and judicious use of computation. Although individual n→π* interactions are relatively weak (∼0.3-0.7 kcal/mol), the ubiquity of carbonyl groups across chemistry and biology gives the n→π* interaction broad impact. In particular, the n→π* interaction is likely to play an important role in dictating protein structure. Indeed, bioinformatics analysis suggests that approximately one-third of residues in folded proteins satisfy the geometric requirements to engage in an n→π* interaction, which is likely to be of particular importance for the α-helix. Other carbonyl-dense polymeric materials like polyesters and peptoids are also influenced by n→π* interactions, as are a variety of small molecules, some with particular medicinal importance. Research will continue to identify molecules whose conformation and activity are affected by the n→π* interaction and will clarify their specific contributions to the structures of biomacromolecules.
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Affiliation(s)
- Robert W. Newberry
- Department
of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
| | - Ronald T. Raines
- Department
of Chemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
- Department
of Biochemistry, University of Wisconsin−Madison, Madison, Wisconsin 53706, United States
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26
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Crowe D, Nicholson A, Fleming A, Carey E, Sánchez-Sanz G, Kelleher F. Conformational studies of Gram-negative bacterial quorum sensing 3-oxo N -acyl homoserine lactone molecules. Bioorg Med Chem 2017; 25:4285-4296. [DOI: 10.1016/j.bmc.2017.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 05/31/2017] [Accepted: 06/05/2017] [Indexed: 11/24/2022]
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27
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Tiekink ER. Supramolecular assembly based on “emerging” intermolecular interactions of particular interest to coordination chemists. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.01.009] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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28
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Kasznel AJ, Zhang Y, Hai Y, Chenoweth DM. Structural Basis for Aza-Glycine Stabilization of Collagen. J Am Chem Soc 2017. [DOI: 10.1021/jacs.7b03398] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Alexander J. Kasznel
- Department of Chemistry and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Yitao Zhang
- Department of Chemistry and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Yang Hai
- Department of Chemistry and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - David M. Chenoweth
- Department of Chemistry and ‡Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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29
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Dual Modes and Dual Emissions of an Amino-Naphthoquinone Derivative. J Fluoresc 2017; 27:1923-1928. [DOI: 10.1007/s10895-017-2130-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 06/13/2017] [Indexed: 11/26/2022]
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30
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Mykhailiuk PK, Kubyshkin V, Bach T, Budisa N. Peptidyl-Prolyl Model Study: How Does the Electronic Effect Influence the Amide Bond Conformation? J Org Chem 2017; 82:8831-8841. [DOI: 10.1021/acs.joc.7b00803] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pavel K. Mykhailiuk
- Taras Shevchenko National University of Kyiv, Chemistry Department, Volodymyrska 64, 01601 Kyiv, Ukraine
- Enamine Limited, Chervonotkatska 78, 01103 Kyiv, Ukraine
| | - Vladimir Kubyshkin
- Institute
of Chemistry, Technical University of Berlin, Müller-Breslau-Strasse 10, 10623 Berlin, Germany
| | - Thorsten Bach
- Lehrstuhl
für Organische Chemie I, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Nediljko Budisa
- Institute
of Chemistry, Technical University of Berlin, Müller-Breslau-Strasse 10, 10623 Berlin, Germany
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31
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Esipova NG, Tumanyan VG. Omnipresence of the polyproline II helix in fibrous and globular proteins. Curr Opin Struct Biol 2017; 42:41-49. [DOI: 10.1016/j.sbi.2016.10.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 10/10/2016] [Accepted: 10/14/2016] [Indexed: 10/20/2022]
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32
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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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