1
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Sakata S, Li J, Yasuno Y, Shinada T, Shin-Ya K, Katsuyama Y, Ohnishi Y. Identification of the Cirratiomycin Biosynthesis Gene Cluster in Streptomyces Cirratus: Elucidation of the Biosynthetic Pathways for 2,3-Diaminobutyric Acid and Hydroxymethylserine. Chemistry 2024; 30:e202400271. [PMID: 38456538 DOI: 10.1002/chem.202400271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 03/08/2024] [Accepted: 03/08/2024] [Indexed: 03/09/2024]
Abstract
Cirratiomycin, a heptapeptide with antibacterial activity, was isolated and characterized in 1981; however, its biosynthetic pathway has not been elucidated. It contains several interesting nonproteinogenic amino acids, such as (2S,3S)-2,3-diaminobutyric acid ((2S,3S)-DABA) and α-(hydroxymethyl)serine, as building blocks. Here, we report the identification of a cirratiomycin biosynthetic gene cluster in Streptomyces cirratus. Bioinformatic analysis revealed that several Streptomyces viridifaciens and Kitasatospora aureofaciens strains also have this cluster. One S. viridifaciens strain was confirmed to produce cirratiomycin. The biosynthetic gene cluster was shown to be responsible for cirratiomycin biosynthesis in S. cirratus in a gene inactivation experiment using CRISPR-cBEST. Interestingly, this cluster encodes a nonribosomal peptide synthetase (NRPS) composed of 12 proteins, including those with an unusual domain organization: a stand-alone adenylation domain, two stand-alone condensation domains, two type II thioesterases, and two NRPS modules that have no adenylation domain. Using heterologous expression and in vitro analysis of recombinant enzymes, we revealed the biosynthetic pathway of (2S,3S)-DABA: (2S,3S)-DABA is synthesized from l-threonine by four enzymes, CirR, CirS, CirQ, and CirB. In addition, CirH, a glycine/serine hydroxymethyltransferase homolog, was shown to synthesize α-(hydroxymethyl)serine from d-serine in vitro. These findings broaden our knowledge of nonproteinogenic amino acid biosynthesis.
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Affiliation(s)
- Shunki Sakata
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Jiafeng Li
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yoko Yasuno
- Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
| | - Tetsuro Shinada
- Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi, Osaka, 558-8585, Japan
| | - Kazuo Shin-Ya
- National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo, 135-0064, Japan
| | - Yohei Katsuyama
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yasuo Ohnishi
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan
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2
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Takeuchi N, Taniguchi M, Kato Y, Takata R, Osaka I, Nakajima N, Hamada M, Koyama Y. Synthesis and Conformational Behaviors of Unnatural Peptides Alternating Chiral and Achiral α,α-Disubstituted α-Amino Acid Units. Macromol Rapid Commun 2023; 44:e2300323. [PMID: 37668077 DOI: 10.1002/marc.202300323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/27/2023] [Indexed: 09/06/2023]
Abstract
The development of peptidomimetics to modulate the conformational profile of peptides has been extensively studied in the fields of biological and medicinal chemistry. However, large-scale synthesis of peptidomimetics with both an ordered sequence and a controlled secondary structure is highly challenging. In this paper, the framework of peptidomimetics has been designed to be alternating an achiral α,α-disubstituted α-amino acid unit and a chiral α-methylphenylalanine unit. The polymers are synthesized via invented Ugi reaction-based polycondensation technique. The chiral higher-order structures of the alternating peptides are evaluated mainly through circular dichroism (CD) spectroscopy. The UV-Vis and CD spectra of the polymers in three solvents are systematically measured at various temperatures. The anisotropic factors of CD (gCD ) values are calculated to know the chiroptical response. The results indicate the characteristic conformational behaviors. In a polar solvent, the hydrogen bonds between the N-H group of MePhe unit and the C=O of α,α-diphenylglycine unit outweigh the intraresidue hydrogen bonds in α,α-diphenylglycine unit, leading to the formation of a prevailing preferred-handed 310 -helical conformation. On the other hand, in a less polar solvent, the intrachain hydrogen bonds switch to intraresidue hydrogen bonds in α,α-diphenylglycine unit, which make the polymer adopting a prevailing extended planar C5 -conformation.
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Affiliation(s)
- Nanami Takeuchi
- Department of Pharmaceutical Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Masataka Taniguchi
- Department of Pharmaceutical Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Yuki Kato
- Department of Pharmaceutical Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Riko Takata
- Department of Pharmaceutical Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Issey Osaka
- Department of Pharmaceutical Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
- Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Noriyuki Nakajima
- Department of Pharmaceutical Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
- Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Masahiro Hamada
- Department of Pharmaceutical Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
- Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
| | - Yasuhito Koyama
- Department of Pharmaceutical Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
- Biotechnology Research Center, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, 939-0398, Japan
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3
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Biondi B, Cardena R, Bisello A, Schiesari R, Cerveson L, Facci M, Rancan M, Formaggio F, Santi S. Flat, Ferrocenyl‐Conjugated Peptides: A Combined Electrochemical and Spectroscopic Study. ChemElectroChem 2021. [DOI: 10.1002/celc.202100597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Barbara Biondi
- Institute of Biomolecular Chemistry Padova Unit, CNR via Marzolo 1 35131 Padova Italy
| | - Roberta Cardena
- Department of Chemical Sciences University of Padova via Marzolo 1 35131 Padova Italy
| | - Annalisa Bisello
- Department of Chemical Sciences University of Padova via Marzolo 1 35131 Padova Italy
| | - Renato Schiesari
- Department of Chemical Sciences University of Padova via Marzolo 1 35131 Padova Italy
| | - Laura Cerveson
- Department of Chemical Sciences University of Padova via Marzolo 1 35131 Padova Italy
| | - Martino Facci
- Department of Chemical Sciences University of Padova via Marzolo 1 35131 Padova Italy
| | - Marzio Rancan
- Institute of Condensed Matter Chemistry and Technologies for Energy (ICMATE), CNR Via Marzolo, 1 35131 Padova Italy
| | - Fernando Formaggio
- Institute of Biomolecular Chemistry Padova Unit, CNR via Marzolo 1 35131 Padova Italy
- Department of Chemical Sciences University of Padova via Marzolo 1 35131 Padova Italy
| | - Saverio Santi
- Department of Chemical Sciences University of Padova via Marzolo 1 35131 Padova Italy
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4
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Terada K, Gimenez-Dejoz J, Kurita T, Oikawa K, Uji H, Tsuchiya K, Numata K. Synthetic Mitochondria-Targeting Peptides Incorporating α-Aminoisobutyric Acid with a Stable Amphiphilic Helix Conformation in Plant Cells. ACS Biomater Sci Eng 2021; 7:1475-1484. [PMID: 33606492 DOI: 10.1021/acsbiomaterials.0c01533] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the genetic modification of plant cells, the mitochondrion is an important target in addition to the nucleus and plastid. However, gene delivery into the mitochondria of plant cells has yet to be established by conventional methods, such as particle bombardment, because of the small size and high mobility of mitochondria. To develop an efficient mitochondria-targeting signal (MTS) that functions in plant cells, we designed the artificial peptide (LURL)3 and its analogues, which periodically feature hydrophobic α-aminoisobutyric acid (Aib, U) and cationic arginine (R), considering the consensus motif recognized by the mitochondrial import receptor Tom20. Circular dichroism measurements and molecular dynamics simulation studies revealed that (LURL)3 had a propensity to form a stable α-helix in 0.1 M phosphate buffer solution containing 1.0 wt % sodium dodecyl sulfate. After internalization into plant cells via particle bombardment, (LURL)3 revealed highly selective accumulation in the mitochondria, whereas its analogue (LARL)3 was predominantly located in the vacuoles in addition to mitochondria. The high selectivity of (LURL)3 can be attributed to the incorporation of Aib, which promotes the hydrophobic interaction between the MTS and Tom20 by increasing the hydrophobicity and helicity of (LURL)3. The present study provided a prospective mitochondrial targeting system using the simple design of artificial peptides.
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Affiliation(s)
- Kayo Terada
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Joan Gimenez-Dejoz
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Taichi Kurita
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kazusato Oikawa
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Hirotaka Uji
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kousuke Tsuchiya
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Keiji Numata
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.,Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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5
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Santi S, Bisello A, Cardena R, Tomelleri S, Schiesari R, Biondi B, Crisma M, Formaggio F. Flat, C α,β -Didehydroalanine Foldamers with Ferrocene Pendants: Assessing the Role of α-Peptide Dipolar Moments. Chempluschem 2021; 86:723-730. [PMID: 33825347 DOI: 10.1002/cplu.202100072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/22/2021] [Indexed: 12/28/2022]
Abstract
The foldamer field is continuously expanding as it allows to produce molecules endowed with 3D-structures and functions never observed in nature. We synthesized flat foldamers based on the natural, but non-coded, Cα,β -didehydroalanine α-amino acid, and covalently linked to them two ferrocene (Fc) moieties, as redox probes. These conjugates retain the flat and extended conformation of the 2.05 -helix, both in solution and in the crystal state (X-ray diffraction). Cyclic voltammetry measurements agree with the adoption of the 2.05 -helix, characterized by a negligible dipole moment. Thus, elongated α-peptide stretches of this type are insulators rather than charge conductors, the latter being constituted by peptide α-helices. Also, our homo-tetrapeptide has a N-to-C length of about 18.2 Å, almost double than that (9.7 Å) of an α-helical α-tetrapeptide.
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Affiliation(s)
- Saverio Santi
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
| | - Annalisa Bisello
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
| | - Roberta Cardena
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
| | - Silvia Tomelleri
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
| | - Renato Schiesari
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
| | - Barbara Biondi
- Institute of Biomolecular Chemistry, Padova Unit, CNR, via Marzolo 1, 35131, Padova, Italy
| | - Marco Crisma
- Institute of Biomolecular Chemistry, Padova Unit, CNR, via Marzolo 1, 35131, Padova, Italy
| | - Fernando Formaggio
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
- Institute of Biomolecular Chemistry, Padova Unit, CNR, via Marzolo 1, 35131, Padova, Italy
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6
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Ueda A, Ikeda M, Kasae T, Doi M, Demizu Y, Oba M, Tanaka M. Synthesis of Chiral α‐Trifluoromethyl α,α‐Disubstituted α‐Amino Acids and Conformational Analysis of L‐Leu‐Based Peptides with (
R
)‐ or (
S
)‐α‐Trifluoromethylalanine. ChemistrySelect 2020. [DOI: 10.1002/slct.202002888] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Atsushi Ueda
- Graduate School of Biomedical Sciences Nagasaki University Nagasaki 852-8521 Japan
| | - Misuzu Ikeda
- Graduate School of Biomedical Sciences Nagasaki University Nagasaki 852-8521 Japan
| | - Takuya Kasae
- Graduate School of Biomedical Sciences Nagasaki University Nagasaki 852-8521 Japan
| | - Mitsunobu Doi
- Osaka University of Pharmaceutical Sciences Osaka 569-1094 Japan
| | - Yosuke Demizu
- Division of Organic Chemistry National Institute of Health Sciences Kawasaki 210 9501 Japan
| | - Makoto Oba
- Kyoto Prefectural University of Medicine Kyoto 606-0823 Japan
| | - Masakazu Tanaka
- Graduate School of Biomedical Sciences Nagasaki University Nagasaki 852-8521 Japan
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7
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Terada K, Gimenez-Dejoz J, Miyagi Y, Oikawa K, Tsuchiya K, Numata K. Artificial Cell-Penetrating Peptide Containing Periodic α-Aminoisobutyric Acid with Long-Term Internalization Efficiency in Human and Plant Cells. ACS Biomater Sci Eng 2020; 6:3287-3298. [DOI: 10.1021/acsbiomaterials.0c00182] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Kayo Terada
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Joan Gimenez-Dejoz
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yu Miyagi
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kazusato Oikawa
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kousuke Tsuchiya
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Keiji Numata
- Biomacromolecules Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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8
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Tsuji G, Misawa T, Doi M, Demizu Y. Extent of Helical Induction Caused by Introducing α-Aminoisobutyric Acid into an Oligovaline Sequence. ACS OMEGA 2018; 3:6395-6399. [PMID: 31458822 PMCID: PMC6644412 DOI: 10.1021/acsomega.8b01030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 06/05/2018] [Indexed: 06/10/2023]
Abstract
The preferred conformations of a dodecapeptide composed of l-valine (l-Val) and α-aminoisobutyric acid (Aib) residues, Boc-(l-Val-l-Val-Aib)4-OMe (3), were analyzed in solution and in the crystalline state. Peptide 3 predominantly folded into a mixture of α- and 310-(P) helical structures in solution and a (P) α helix in the crystalline state.
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Affiliation(s)
- Genichiro Tsuji
- Division
of Organic Chemistry, National Institute
of Health Sciences, Kanagawa 210-9501, Japan
| | - Takashi Misawa
- Division
of Organic Chemistry, National Institute
of Health Sciences, Kanagawa 210-9501, Japan
| | - Mitsunobu Doi
- Osaka
University of Pharmaceutical Sciences, Osaka 569-1094, Japan
| | - Yosuke Demizu
- Division
of Organic Chemistry, National Institute
of Health Sciences, Kanagawa 210-9501, Japan
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9
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Nadimpally KC, Madica K, Kotmale AS, Gonnade RG, Sanjayan GJ. Helically Structured Peptide Architecture Engineered Using Dimedone as a Rigid Organic Scaffold. ChemistrySelect 2018. [DOI: 10.1002/slct.201702856] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Krishna C. Nadimpally
- Division of Organic Chemistry; National Chemical Laboratory; Dr. Homi Bhabha Road Pune 411008 India
| | - Krishnaprasad Madica
- Division of Organic Chemistry; National Chemical Laboratory; Dr. Homi Bhabha Road Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR); CSIR; Pune 411008 India
| | - Amol S. Kotmale
- Central NMR facility; CSIR-National Chemical Laboratory (CSIR-NCL); Dr. Homi Bhabha Road Pune 411008 India
| | - Rajesh G. Gonnade
- Center for Materials Characterization; National Chemical Laboratory; Dr. Homi Bhahba Road Pune 411008 India
| | - Gangadhar J. Sanjayan
- Division of Organic Chemistry; National Chemical Laboratory; Dr. Homi Bhabha Road Pune 411008 India
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10
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Crisma M, Formaggio F, Alemán C, Torras J, Ramakrishnan C, Kalmankar N, Balaram P, Toniolo C. The fully‐extended conformation in peptides and proteins. Pept Sci (Hoboken) 2018. [DOI: 10.1002/bip.23100] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Marco Crisma
- Institute of Biomolecular Chemistry, Padova Unit, CNRPadova35131 Italy
| | - Fernando Formaggio
- Institute of Biomolecular Chemistry, Padova Unit, CNRPadova35131 Italy
- Department of ChemistryUniversity of PadovaPadova35131 Italy
| | - Carlos Alemán
- Departament d'Enginyeria QuímicaEEBE, Universitat Politècnica de CatalunyaBarcelona08019 Spain
- Barcelona Research Center in Multiscale Science and EngineeringUniversitat Politècnica de CatalunyaBarcelona08019 Spain
| | - Joan Torras
- Departament d'Enginyeria QuímicaEEBE, Universitat Politècnica de CatalunyaBarcelona08019 Spain
- Barcelona Research Center in Multiscale Science and EngineeringUniversitat Politècnica de CatalunyaBarcelona08019 Spain
| | | | - Neha Kalmankar
- National Centre for Biological Sciences (TIFR), GKVK CampusBangalore560065 India
| | | | - Claudio Toniolo
- Institute of Biomolecular Chemistry, Padova Unit, CNRPadova35131 Italy
- Department of ChemistryUniversity of PadovaPadova35131 Italy
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11
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Kobayashi H, Misawa T, Matsuno K, Demizu Y. Preorganized Cyclic α,α-Disubstituted α-Amino Acids Bearing Functionalized Side Chains That Act as Peptide-Helix Inducers. J Org Chem 2017; 82:10722-10726. [DOI: 10.1021/acs.joc.7b01946] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Hiroyuki Kobayashi
- Division
of Organic Chemistry, National Institute of Health Sciences, Tokyo 158-8501, Japan
- Department
of Chemistry and Life Science, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015, Japan
| | - Takashi Misawa
- Division
of Organic Chemistry, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Kenji Matsuno
- Department
of Chemistry and Life Science, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015, Japan
| | - Yosuke Demizu
- Division
of Organic Chemistry, National Institute of Health Sciences, Tokyo 158-8501, Japan
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12
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Misawa T, Imamura M, Ozawa Y, Haishima K, Kurihara M, Kikuchi Y, Demizu Y. Development of helix-stabilized antimicrobial peptides composed of lysine and hydrophobic α,α-disubstituted α-amino acid residues. Bioorg Med Chem Lett 2017; 27:3950-3953. [PMID: 28789896 DOI: 10.1016/j.bmcl.2017.07.074] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 07/25/2017] [Accepted: 07/28/2017] [Indexed: 01/14/2023]
Abstract
Lysine-based amphipathic nonapeptides, including homochiral peptides [Ac-(l-Lys-l-Lys-Xaa)3-NH2 (Xaa=Gly, Ala, Aib, Ac5c, or Ac6c) and Ac-(d-Lys-d-Lys-Aib)3-NH2], a heterochiral peptide [Ac-(l-Lys-d-Lys-Aib)3-NH2], and a racemic mixture of diastereomeric peptides [Ac-(rac-Lys-rac-Lys-Aib)3-NH2] were designed and synthesized to investigate the relationship between their preferred secondary structures and their antimicrobial activity. Peptide 5, [Ac-(l-Lys-l-Lys-Ac6c)3-NH2] formed a stable α-helical structure and exhibited strong activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa).
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Affiliation(s)
- Takashi Misawa
- National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan
| | - Mitsuyoshi Imamura
- National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan
| | - Yuto Ozawa
- National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan
| | - Kazuchika Haishima
- National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan
| | - Masaaki Kurihara
- National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan
| | - Yutaka Kikuchi
- National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan.
| | - Yosuke Demizu
- National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya, Tokyo 158-8501, Japan.
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13
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Furukawa K, Oba M, Toyama K, Opiyo GO, Demizu Y, Kurihara M, Doi M, Tanaka M. Low pH-triggering changes in peptide secondary structures. Org Biomol Chem 2017; 15:6302-6305. [DOI: 10.1039/c7ob01374d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An acidic treatment of cyclic α,α-disubstituted α-amino acid-containing peptides changes their conformation from a helical to a random structure.
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Affiliation(s)
- Kaori Furukawa
- Graduate School of Biomedical Sciences
- Nagasaki University
- Nagasaki 852-8521
- Japan
| | - Makoto Oba
- Graduate School of Biomedical Sciences
- Nagasaki University
- Nagasaki 852-8521
- Japan
| | - Kotomi Toyama
- Graduate School of Biomedical Sciences
- Nagasaki University
- Nagasaki 852-8521
- Japan
| | - George Ouma Opiyo
- Graduate School of Biomedical Sciences
- Nagasaki University
- Nagasaki 852-8521
- Japan
| | - Yosuke Demizu
- National Institute of Health Sciences
- Tokyo 158-8501
- Japan
| | - Masaaki Kurihara
- Department of Pharmaceutical Sciences
- International University of Health and Welfare
- Ohtawara
- Japan
| | - Mitsunobu Doi
- Osaka University of Pharmaceutical Sciences
- Osaka 569-1094
- Japan
| | - Masakazu Tanaka
- Graduate School of Biomedical Sciences
- Nagasaki University
- Nagasaki 852-8521
- Japan
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14
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Crisma M, Peggion C, Moretto A, Banerjee R, Supakar S, Formaggio F, Toniolo C. The 2.0₅-helix in hetero-oligopeptides entirely composed of C(α,α)-disubstituted glycines with both side chains longer than methyls. Biopolymers 2016; 102:145-58. [PMID: 24307568 DOI: 10.1002/bip.22450] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/15/2013] [Accepted: 12/02/2013] [Indexed: 02/02/2023]
Abstract
The existence of the very uncommon, but potentially quite interesting, multiple, consecutive fully-extended conformation (2.0₅-helix) has been already clearly demonstrated in homo-oligopeptides based on quaternary α-amino acids with both side chains longer than methyls, but not cyclized on the α-carbon atom. To extend the scope of this research, in this work we investigated the occurrence of this flat 3D-structure in hetero-oligopeptides, each composed of two or three different residues of that class. The synthesis of a terminally protected peptide series to the tetrapeptide level was carried out by solution methods. The resulting oligomers were chemically and conformationally characterized. The data obtained point to an overwhelming population of the fully-extended conformation in CDCl3. However, a solvent-driven switch to a predominant 3₁₀-helical structure was seen in CD3CN. A delicate, local balance between these two conformations is confirmed to occur in the crystalline state. Molecular dynamics simulations in CHCl3 on a hetero-tetrapeptide converged to the fully-extended conformation even starting from the 3₁₀-helical structure.
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Affiliation(s)
- Marco Crisma
- Department of Chemistry, ICB, Padova Unit, CNR, University of Padova, 35131, Padova, Italy
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15
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Crisma M, Toniolo C. Helical screw-sense preferences of peptides based on chiral, Cα-tetrasubstituted α-amino acids. Biopolymers 2016; 104:46-64. [PMID: 25363510 DOI: 10.1002/bip.22581] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/14/2014] [Accepted: 10/24/2014] [Indexed: 01/09/2023]
Abstract
The preferred helical screw senses of chiral α-amino acids with a C(α)-tetrasubstituted α-carbon atom, as determined in the crystal state by X-ray diffraction analyses on derivatives and peptides, are reviewed. This survey covers C(α)-methylated and C(α)-ethylated α-amino acids, as well as α-amino acids cyclized on the α-carbon, including those characterized by the combination of lack of chirality at the α-carbon with either side-chain or axial chirality. Although, in general, chiral C(α)-tetrasubstituted α-amino acids show a less pronounced bias toward a single helical screw sense than their proteinogenic (C(α)-trisubstituted) counterparts, our analysis highlights significant differences in terms of magnitude and direction of such a bias among the various sub-families of residues, and between individual amino acids within each sub-family as well. The experimental findings can be rationalized, at least in part, on the basis of steric considerations.
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Affiliation(s)
- Marco Crisma
- Institute of Biomolecular Chemistry, Padova Unit, CNR, 35131, Padova, Italy
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16
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Demizu Y, Okitsu K, Yamashita H, Doi M, Misawa T, Oba M, Tanaka M, Kurihara M. α-Helical Structures of Oligopeptides with an Alternating l-Leu-Aib Segment. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600327] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Yosuke Demizu
- National Institute of Health Sciences; Setagaya 158-8501 Tokyo Japan
| | - Koyo Okitsu
- National Institute of Health Sciences; Setagaya 158-8501 Tokyo Japan
| | - Hiroko Yamashita
- National Institute of Health Sciences; Setagaya 158-8501 Tokyo Japan
| | - Mitsunobu Doi
- Osaka University of Pharmaceutical Sciences; 569-1094 Osaka Japan
| | - Takashi Misawa
- National Institute of Health Sciences; Setagaya 158-8501 Tokyo Japan
| | - Makoto Oba
- Graduate School of Biomedical Sciences; Nagasaki University; 852-8521 Nagasaki Japan
| | - Masakazu Tanaka
- Graduate School of Biomedical Sciences; Nagasaki University; 852-8521 Nagasaki Japan
| | - Masaaki Kurihara
- National Institute of Health Sciences; Setagaya 158-8501 Tokyo Japan
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17
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Peggion C, Moretto A, Formaggio F, Crisma M, Toniolo C. Multiple, consecutive, fully-extended 2.0₅-helix peptide conformation. Biopolymers 2016; 100:621-36. [PMID: 23893391 DOI: 10.1002/bip.22267] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 04/16/2013] [Accepted: 04/19/2013] [Indexed: 02/01/2023]
Abstract
The peptide 2.0(5)-helix does exist. It has been experimentally authenticated both in the crystalline state (by X-ray diffraction) and in solution (by several spectroscopic techniques). It is the most common conformation for C(α)-tetrasubstituted α-amino acids with at least two atoms in each side chain, provided that cyclization on the C(α)-atom is absent. X-Ray diffraction has allowed a detailed description of its geometrical and three-dimensional (3D)-structural features. The infrared absorption and the nuclear magnetic resonance parameters characteristics of this multiple, consecutive, fully-extended structure have been described. Conformational energy calculations are in agreement with the experimental findings. As the contribution per amino acid residue to the length of this helix is the longest possible, its exploitation as a molecular spacer is quite promising. However, it is a rather fragile 3D-structure and particularly sensitive to solvent polarity. Interestingly, in such a case, it may reversibly convert to the much shorter 3(10)-helix, thus generating an attractive molecular spring.
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Affiliation(s)
- Cristina Peggion
- Institute of Biomolecular Chemistry, CNR, Padova Unit, Department of Chemistry, University of Padova, 35131, Padova, Italy
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18
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Oba M, Nonaka H, Doi M, Tanaka M. Conformational studies on peptides having dipropylglycine (Dpg) or 1-aminocycloheptanecarboxylic acid (Ac7c) within the sequence ofl-leucine (Leu) residues. Biopolymers 2016; 106:210-218. [DOI: 10.1002/bip.22810] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/09/2015] [Accepted: 01/10/2016] [Indexed: 01/12/2023]
Affiliation(s)
- Makoto Oba
- Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki 852-8521 Japan
| | - Hikaru Nonaka
- Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki 852-8521 Japan
| | - Mitsunobu Doi
- Osaka University of Pharmaceutical Sciences; Osaka 569-1094 Japan
| | - Masakazu Tanaka
- Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki 852-8521 Japan
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19
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Demizu Y, Yamashita H, Misawa T, Doi M, Oba M, Tanaka M, Kurihara M. Handedness Preferences of Heterochiral Helical Peptides Containing Homochiral Peptide Segments. European J Org Chem 2016. [DOI: 10.1002/ejoc.201501146] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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20
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Yamashita H, Oba M, Misawa T, Tanaka M, Hattori T, Naito M, Kurihara M, Demizu Y. A Helix-Stabilized Cell-Penetrating Peptide as an Intracellular Delivery Tool. Chembiochem 2015; 17:137-40. [DOI: 10.1002/cbic.201500468] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Hiroko Yamashita
- National Institute of Health Sciences; Setagaya Tokyo 158-8501 Japan
- Graduate School of Bioscience and Biotechnology; Tokyo Institute of Technology; Yokohama 226-8501 Japan
| | - Makoto Oba
- Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki 852-8521 Japan
| | - Takashi Misawa
- National Institute of Health Sciences; Setagaya Tokyo 158-8501 Japan
| | - Masakazu Tanaka
- Graduate School of Biomedical Sciences; Nagasaki University; Nagasaki 852-8521 Japan
| | - Takayuki Hattori
- National Institute of Health Sciences; Setagaya Tokyo 158-8501 Japan
| | - Mikihiko Naito
- National Institute of Health Sciences; Setagaya Tokyo 158-8501 Japan
| | - Masaaki Kurihara
- National Institute of Health Sciences; Setagaya Tokyo 158-8501 Japan
- Graduate School of Bioscience and Biotechnology; Tokyo Institute of Technology; Yokohama 226-8501 Japan
| | - Yosuke Demizu
- National Institute of Health Sciences; Setagaya Tokyo 158-8501 Japan
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Demizu Y, Yamashita H, Doi M, Misawa T, Oba M, Tanaka M, Kurihara M. Topological Study of the Structures of Heterochiral Peptides Containing Equal Amounts of l-Leu and d-Leu. J Org Chem 2015; 80:8597-603. [PMID: 26274390 DOI: 10.1021/acs.joc.5b01541] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We designed and synthesized two dodecapeptides, Boc-(l-Leu-l-Leu-Aib-d-Leu-d-Leu-Aib)2-OMe (5) and Boc-l-Leu-l-Leu-Aib-(d-Leu-d-Leu-Aib)2-l-Leu-l-Leu-Aib-OMe (6), that contain equal amounts of l-Leu, d-Leu, and achiral Aib residues. The conformations of peptides 5 and 6 in the crystalline state were studied using X-ray crystallographic analysis. Peptide 5 formed a left-handed (M) α-helical structure, whereas peptide 6 was composed of a combination of fused (M) α-helical and right-handed (P) 310-helical structures. In solution, roughly equivalent amounts of (P) and (M) helices were present in 5, whereas the (M) α-helix was present in 6 as its dominant conformation.
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Affiliation(s)
- Yosuke Demizu
- Division of Organic Chemistry, National Institute of Health Sciences , Tokyo 158-8501, Japan
| | - Hiroko Yamashita
- Division of Organic Chemistry, National Institute of Health Sciences , Tokyo 158-8501, Japan.,Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology , Yokohama 226-8501, Japan
| | - Mitsunobu Doi
- Osaka University of Pharmaceutical Sciences , Osaka 569-1094, Japan
| | - Takashi Misawa
- Division of Organic Chemistry, National Institute of Health Sciences , Tokyo 158-8501, Japan
| | - Makoto Oba
- Graduate School of Biomedical Sciences, Nagasaki University , Nagasaki 852-8521, Japan
| | - Masakazu Tanaka
- Graduate School of Biomedical Sciences, Nagasaki University , Nagasaki 852-8521, Japan
| | - Masaaki Kurihara
- Division of Organic Chemistry, National Institute of Health Sciences , Tokyo 158-8501, Japan.,Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology , Yokohama 226-8501, Japan
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22
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Abstract
The conformational behaviour of Ac-Gly-NHMe and its fluorinated [CF3-C(O)-Gly-NHMe] and N-methyl[Ac-Gly-N(Me)2] derivatives is investigated in nonpolar, polar and polar protic solutions by NMR and IR spectroscopies and theoretical calculations.
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Affiliation(s)
- R. A. Cormanich
- EastChem School of Chemistry
- University of St Andrews
- St Andrews
- UK
- Chemistry Institute
| | - R. Rittner
- Chemistry Institute
- State University of Campinas
- Campinas
- Brazil
| | - M. Bühl
- EastChem School of Chemistry
- University of St Andrews
- St Andrews
- UK
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23
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Tumminakatti S, Reddy DN, Prabhakaran EN. Exploring the consequences of a representative "disallowed" conformation of Aib on a 3₁₀-helical fold. Biopolymers 2014; 104:21-36. [PMID: 25488434 DOI: 10.1002/bip.22599] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 11/28/2014] [Accepted: 12/01/2014] [Indexed: 01/24/2023]
Abstract
The structural effects of a representative "disallowed" conformation of Aib on the 3(10)-helical fold of an octapeptidomimetic are explored. The 1D ((1)H, (13)C) & 2D NMR, FT-IR and CD data reveal that the octapeptide 1, adopts a 3(10)-helical conformation in solution, as it does in its crystal structure. The C-terminal methyl carboxylate (CO2Me) of 1 was modified into an 1,3-oxazine (Oxa) functional group in the peptidomimetic 2. This modification results in the stabilization of the backbone of the C-terminal Aib (Aib*-Oxa) of 2, in a conformation (ϕ, ψ = 180, 0) that is natively disallowed to Aib. Consequent to the presence of this natively disallowed conformation, the 3(10)-helical fold is not disrupted in the body of the peptidomimetic 2. But the structural distortions that do occur in 2 are primarily in residues in the immediate vicinity of the natively disallowed conformation, rather than in the whole peptide body. Non-native electronic effects resulting from modifications in backbone functional groups can be at the origin of stabilizing residues in natively disallowed conformations.
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Affiliation(s)
- Shama Tumminakatti
- Department of Organic Chemistry, Indian Institute of Science, Bangalore, 560012, Karnataka, India
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24
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Oba M, Kawabe N, Takazaki H, Demizu Y, Doi M, Kurihara M, Suemune H, Tanaka M. Conformational studies on peptides having chiral five-membered ring amino acid with two azido or triazole functional groups within the sequence of Aib residues. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.09.086] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Oba M, Takazaki H, Kawabe N, Doi M, Demizu Y, Kurihara M, Kawakubo H, Nagano M, Suemune H, Tanaka M. Helical Peptide-Foldamers Having a Chiral Five-Membered Ring Amino Acid with Two Azido Functional Groups. J Org Chem 2014; 79:9125-40. [DOI: 10.1021/jo501493x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Makoto Oba
- Graduate
School of Biomedical Sciences, Nagasaki University, 1-14 Bukyo-machi, Nagasaki 852-8521, Japan
| | - Hiroomi Takazaki
- Graduate
School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Naomi Kawabe
- Graduate
School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Mitsunobu Doi
- Osaka University of Pharmaceutical Sciences, Osaka 569-1094, Japan
| | - Yosuke Demizu
- Division
of Organic Chemistry, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Masaaki Kurihara
- Division
of Organic Chemistry, National Institute of Health Sciences, Tokyo 158-8501, Japan
| | - Hiromu Kawakubo
- Department
of Pharmaceutical Sciences, Nihon Pharmaceutical University, Saitama 362-0806, Japan
| | - Masanobu Nagano
- Graduate
School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Hiroshi Suemune
- Graduate
School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Masakazu Tanaka
- Graduate
School of Biomedical Sciences, Nagasaki University, 1-14 Bukyo-machi, Nagasaki 852-8521, Japan
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26
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Wani NA, Gupta VK, Kant R, Aravinda S, Rai R. Conformation of a terminally protected βγ hybrid dipeptide Boc-Ant-Gpn-OMe stabilized by C6/C7 hydrogen bonds. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2014; 70:46-9. [PMID: 24399225 DOI: 10.1107/s2053229613033044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 12/06/2013] [Indexed: 11/11/2022]
Abstract
The hybrid βγ dipeptide, methyl 2-[1-({2-[(tert-butoxycarbonyl)amino]benzamido}methyl)cyclohexyl]acetate (Boc-Ant-Gpn-OMe), C22H32N2O5, adopts a folded conformation stabilized by intramolecular six- (C6) and seven-membered (C7) hydrogen-bonded rings, together with weak C-H...O and C-H...π interactions, resulting in a ribbon-like structure.
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Affiliation(s)
- Naiem Ahmad Wani
- Medicinal Chemistry Division, Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi 180 001, India
| | - Vivek Kumar Gupta
- X-ray Crystallography Laboratory, Post-Graduate Department of Physics & Electronics, University of Jammu, Jammu Tawi 180 006, India
| | - Rajni Kant
- X-ray Crystallography Laboratory, Post-Graduate Department of Physics & Electronics, University of Jammu, Jammu Tawi 180 006, India
| | - Subrayashastry Aravinda
- Medicinal Chemistry Division, Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi 180 001, India
| | - Rajkishor Rai
- Medicinal Chemistry Division, Indian Institute of Integrative Medicine, Canal Road, Jammu Tawi 180 001, India
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Reddy DN, Prabhakaran EN. Steric and electronic interactions controlling the cis/trans isomer equilibrium at X-pro tertiary amide motifs in solution. Biopolymers 2013; 101:66-77. [DOI: 10.1002/bip.22278] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 04/27/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Damodara N. Reddy
- Department of Organic Chemistry; Indian Institute of Science; Bangalore 560012 Karnataka India
| | - Erode N. Prabhakaran
- Department of Organic Chemistry; Indian Institute of Science; Bangalore 560012 Karnataka India
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28
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Oba M, Ishikawa N, Demizu Y, Kurihara M, Suemune H, Tanaka M. Helical Oligomers with a Changeable Chiral Acetal Moiety. European J Org Chem 2013. [DOI: 10.1002/ejoc.201301450] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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29
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30
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Formaggio F, Crisma M, Peggion C, Moretto A, Venanzi M, Toniolo C. Looking for a Robust, Synthetic, Fully-Extended (2.05-Helical) Peptide Structure - Effect of Terminal Groups. European J Org Chem 2011. [DOI: 10.1002/ejoc.201101273] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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31
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Editorial to the special issue foldamers. Amino Acids 2011; 41:537-9. [PMID: 21647663 DOI: 10.1007/s00726-011-0943-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 05/12/2011] [Indexed: 10/18/2022]
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