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Simultaneous Ring-Opened THF and insertion of diazoketone derived carbene into carbonyl O-H: Synthesis for β-keto enol ethers. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.07.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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HIRAMA M. Total synthesis and related studies of large, strained, and bioactive natural products. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2016; 92:290-329. [PMID: 27725470 PMCID: PMC5243947 DOI: 10.2183/pjab.92.290] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/10/2016] [Indexed: 06/06/2023]
Abstract
Our chemical syntheses and related scientific investigations of natural products with complex architectures and powerful biological activities are described, focusing on the very large 3 nm-long polycyclic ethers called the ciguatoxins, highly strained and labile chromoprotein antitumor antibiotics featuring nine-membered enediyne cores, and extremely potent anthelmintic macrolides called the avermectins.
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Affiliation(s)
- Masahiro HIRAMA
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
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3
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Nishio M, Umezawa Y, Fantini J, Weiss MS, Chakrabarti P. CH-π hydrogen bonds in biological macromolecules. Phys Chem Chem Phys 2015; 16:12648-83. [PMID: 24836323 DOI: 10.1039/c4cp00099d] [Citation(s) in RCA: 335] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This is a sequel to the previous Perspective "The CH-π hydrogen bond in chemistry. Conformation, supramolecules, optical resolution and interactions involving carbohydrates", which featured in a PCCP themed issue on "Weak Hydrogen Bonds - Strong Effects?": Phys. Chem. Chem. Phys., 2011, 13, 13873-13900. Evidence that weak hydrogen bonds play an enormously important role in chemistry and biochemistry has now accumulated to an extent that the rigid classical concept of hydrogen bonds formulated by Pauling needs to be seriously revised and extended. The concept of a more generalized hydrogen bond definition is indispensable for understanding the folding mechanisms of proteins. The CH-π hydrogen bond, a weak molecular force occurring between a soft acid CH and a soft base π-electron system, among all is one of the most important and plays a functional role in defining the conformation and stability of 3D structures as well as in many molecular recognition events. This concept is also valuable in structure-based drug design efforts. Despite their frequent occurrence in organic molecules and bio-molecules, the importance of CH-π hydrogen bonds is still largely unknown to many chemists and biochemists. Here we present a review that deals with the evidence, nature, characteristics and consequences of the CH-π hydrogen bond in biological macromolecules (proteins, nucleic acids, lipids and polysaccharides). It is hoped that the present Perspective will show the importance of CH-π hydrogen bonds and stimulate interest in the interactions of biological macromolecules, one of the most fascinating fields in bioorganic chemistry. Implication of this concept is enormous and valuable in the scientific community.
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Affiliation(s)
- Motohiro Nishio
- The CHPI Institute, 705-6-338, Minamioya, Machida-shi, Tokyo 194-0031, Japan.
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Das P, Valente EJ, Hamme AT. A Model Study toward the Concise Synthesis of Bromotyrosine Derived Spiroisoxazoline Natural Products and Analogous Core Structures. European J Org Chem 2014; 2014:2659-2663. [PMID: 24891836 PMCID: PMC4039208 DOI: 10.1002/ejoc.201400009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Indexed: 11/06/2022]
Abstract
A model study of the first non-aromatic ring based approach toward α-hydroxyspiroisoxazolines resembling the bromotyrosine derived natural product and analogous spiroisoxazoline core structures were implemented. The desired molecular architecture was achieved through the multifunctionalization of a key 1,3-diketo spiroisoxazoline. Our strategy could serve as an efficient alternative of previously developed approaches that utilize an aromatic ring oxidation as the essential step to synthesize this class of natural products.
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Affiliation(s)
- Prasanta Das
- Department of Chemistry & Biochemistry, Jackson State University 1400 J. R. Lynch St, PO Box 17910, Jackson, Ms 39217, USA, Fax: (+)1 601 979 3674, Tel: (+)1 601 979 3713, Homepage: http://www.jsums.edu/chemistry/ashton-t-hamme-ii/
| | - Edward J. Valente
- Department of Chemistry, University of Portland, 5000 N Willamette Blvd., Portland, OR 97203, USA
| | - Ashton T. Hamme
- Department of Chemistry & Biochemistry, Jackson State University 1400 J. R. Lynch St, PO Box 17910, Jackson, Ms 39217, USA, Fax: (+)1 601 979 3674, Tel: (+)1 601 979 3713, Homepage: http://www.jsums.edu/chemistry/ashton-t-hamme-ii/
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Chi HW, Huang CC, Chin DH. Thiols Screened by the Neocarzinostatin Protein for Preserving or Detoxifying its Bound Enediyne Antibiotic. Chemistry 2012; 18:6238-49. [DOI: 10.1002/chem.201102825] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 01/12/2012] [Indexed: 12/28/2022]
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Eshghi H, Hassankhani A. Phosphorus pentoxide supported on silica gel and alumina (P2O5/SiO2, P2O5/Al2O3) as useful catalysts in organic synthesis. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2012. [DOI: 10.1007/s13738-011-0057-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Chi HW, Chien YC, Liu CY, Tseng CJ, Lee YJ, Chan JL, Chu YR, Chin DH. Role of Steric Effects in Protein-Directed Enediyne Cycloaromatization of Neocarzinostatin. Chemistry 2010; 17:1493-506. [DOI: 10.1002/chem.201002330] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Indexed: 12/15/2022]
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Hariharan P, Sudhahar CG, Chou SH, Chin DH. Lipid Bilayer-Assisted Release of an Enediyne Antibiotic from Neocarzinostatin Chromoprotein. Biochemistry 2010; 49:7722-32. [DOI: 10.1021/bi100735v] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Parameswaran Hariharan
- Department of Chemistry, National Chung Hsing University, Taichung 40227, Taiwan, ROC
- Institute of Biochemistry, National Chung Hsing University, Taichung 40227, Taiwan, ROC
| | | | - Shan-Ho Chou
- Institute of Biochemistry, National Chung Hsing University, Taichung 40227, Taiwan, ROC
| | - Der-Hang Chin
- Department of Chemistry, National Chung Hsing University, Taichung 40227, Taiwan, ROC
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White DE, Stewart IC, Seashore-Ludlow BA, Grubbs RH, Stoltz BM. A general enantioselective route to the chamigrene natural product family. Tetrahedron 2010; 66:4668-4686. [PMID: 20798895 PMCID: PMC2925317 DOI: 10.1016/j.tet.2010.04.128] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Described in this report is an enantioselective route toward the chamigrene natural product family. The key disconnections in our synthetic approach include sequential enantioselective decarboxylative allylation and ring-closing olefin metathesis to form the all-carbon quaternary stereocenter and spirocyclic core present in all members of this class of compounds. The generality of this strategy is demonstrated by the first total syntheses of elatol and the proposed structure of laurencenone B, as well as the first enantioselective total syntheses of laurencenone C and α-chamigrene. A brief exploration of the substrate scope of the enantioselective decarboxylative allylation/ring-closing metathesis sequence with fully substituted vinyl chlorides is also presented.
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Affiliation(s)
- David E. White
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Ian C. Stewart
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | | | - Robert H. Grubbs
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Brian M. Stoltz
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
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Yadav JS, Reddy BVS, Mishra AK. Zinc-mediated Alkylation and Acylation of 1,3-Dicarbonyl Compounds. CHEM LETT 2010. [DOI: 10.1246/cl.2010.280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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11
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Powell JR, Dixon S, Light ME, Kilburn JD. Samarium diiodide-mediated intramolecular cyclodimerisation of bis-α,β-unsaturated carbonyl compounds. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.03.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Luo Y, Lin S, Zhang J, Cooke HA, Bruner SD, Shen B. Regiospecific O-methylation of naphthoic acids catalyzed by NcsB1, an O-methyltransferase involved in the biosynthesis of the enediyne antitumor antibiotic neocarzinostatin. J Biol Chem 2008; 283:14694-702. [PMID: 18387946 DOI: 10.1074/jbc.m802206200] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Neocarzinostatin, a clinical anticancer drug, is the archetypal member of the chromoprotein family of enediyne antitumor antibiotics that are composed of a nonprotein chromophore and an apoprotein. The neocarzinostatin chromophore consists of a nine-membered enediyne core, a deoxyaminosugar, and a naphthoic acid moiety. We have previously cloned and sequenced the neocarzinostatin biosynthetic gene cluster and proposed that the biosynthesis of the naphthoic acid moiety and its incorporation into the neocarzinostatin chromophore are catalyzed by five enzymes NcsB, NcsB1, NcsB2, NcsB3, and NcsB4. Here we report the biochemical characterization of NcsB1, unveiling that: (i) NcsB1 is an S-adenosyl-L-methionine-dependent O-methyltransferase; (ii) NcsB1 catalyzes regiospecific methylation at the 7-hydroxy group of its native substrate, 2,7-dihydroxy-5-methyl-1-naphthoic acid; (iii) NcsB1 also recognizes other dihydroxynaphthoic acids as substrates and catalyzes regiospecific O-methylation; and (iv) the carboxylate and its ortho-hydroxy groups of the substrate appear to be crucial for NcsB1 substrate recognition and binding, and O-methylation takes place only at the free hydroxy group of these dihydroxynaphthoic acids. These findings establish that NcsB1 catalyzes the third step in the biosynthesis of the naphthoic acid moiety of the neocarzinostatin chromophore and further support the early proposal for the biosynthesis of the naphthoic acid and its incorporation into the neocarzinostatin chromophore with free naphthoic acids serving as intermediates. NcsB1 represents another opportunity that can now be exploited to produce novel neocarzinostatin analogs by engineering neocarzinostatin biosynthesis or applying directed biosynthesis strategies.
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Affiliation(s)
- Yinggang Luo
- Division of Pharmaceutical Sciences, University of Wisconsin National Cooperative Drug Discovery Group, Department of Chemistry, University of Wisconsin, Madison, WI 53705, USA
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Teplý F, Stará IG, Starý I, Kollárovič A, Luštinec D, Krausová Z, Šaman D, Fiedler P. A Convenient Route to 2-Hydroxy- and 2,15-Dihydroxyhexahelicene. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700381] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Das B, Laxminarayana K, Ravikanth B. Application of heterogeneous catalysts for an efficient synthesis of β-keto enol ethers. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcata.2007.02.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Baker JR, Woolfson DN, Muskett FW, Stoneman RG, Urbaniak MD, Caddick S. Protein–Small Molecule Interactions in Neocarzinostatin, the Prototypical Enediyne Chromoprotein Antibiotic. Chembiochem 2007; 8:704-17. [PMID: 17451164 DOI: 10.1002/cbic.200600534] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The enediyne chromoproteins are a class of potent antitumour antibiotics comprising a 1:1 complex of a protein and a noncovalently bound chromophore. The protein is required to protect and transport the highly labile chromophore, which acts as the cytotoxic component by reacting with DNA leading to strand cleavage. A derivative of the best-studied member of this class, neocarzinostatin (NCS), is currently in use as a chemotherapeutic in Japan. The application of the chromoproteins as therapeutics along with their unique mode of action has prompted widespread interest in this area. Notable developments include the discovery of non-natural ligands for the apoproteins and the observation that multiple binding modes are available for these ligands in the binding site. Mutation studies on the apoproteins have revealed much about their stability and variability, and the application of an in vitro evolution method has conferred new binding specificity for unrelated ligands. These investigations hold great promise for the application of the apoproteins for drug-delivery, transport and stabilisation systems.
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Affiliation(s)
- James R Baker
- University College London, Department of Chemistry, Christopher Ingold Laboratories, 20 Gordon Street, London, WC1H 0AJ, UK
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Caeiro J, Peña D, Cobas A, Pérez D, Guitián E. Asymmetric Catalysis in the [2+2+2] Cycloaddition of Arynes and Alkynes: Enantioselective Synthesis of a Pentahelicene. Adv Synth Catal 2006. [DOI: 10.1002/adsc.200600319] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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Amonkar CP, Patre RR, Tilve SG. Expedient Synthesis of 2‐Carboethoxy‐4‐methylnaphthalenes. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397910500328605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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18
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Kobayashi S, Hori M, Wang GX, Hirama M. Formal total synthesis of neocarzinostatin chromophore. J Org Chem 2006; 71:636-44. [PMID: 16408974 DOI: 10.1021/jo052031o] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] An efficient route to the neocarzinostatin chromophore aglycon has been developed. The present strategy involves a stereoselective intramolecular acetylide-aldehyde cyclization to form the C5-C6 bond, followed by efficient installation of alpha-epoxide, naphthoate, and carbonate functionalities. The C8-C9-olefin was introduced by using the Martin sulfurane dehydration reaction to furnish the highly reactive aglycon.
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Affiliation(s)
- Shoji Kobayashi
- Department of Chemistry, Graduate Schools of Science, Tohoku University, Sendai 980-8578, Japan.
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Curini M, Epifano F, Genovese S. Ytterbium triflate catalyzed synthesis of β-keto enol ethers. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.04.121] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Antitumor antibiotic chromoproteins such as neocarzinostatin involve a labile toxin that is tightly bound by a protective protein with very high affinity but must also be freed to exert its function. Contrary to the prevalent concept of ligand release, we established that toxin release from neocarzinostatin requires no major backbone conformational changes. We report, herein, that subtle changes in the side chains of specific amino acid residues are adequate to gate the release of chromophore. A recombinant wild type aponeocarzinostatin and its variants mutated around the opening of the chromophore binding cleft are employed to identify specific side chains likely to affect chromophore release. Preliminary, biophysical characterization of mutant apoproteins by circular dichroism and thermal denaturation indicate that the fundamental structural characteristics of wild type protein are conserved in these mutants. The chromophore reconstitution studies further show that all mutants are able to bind chromophore efficiently with similar complex structures. NMR studies on 15N-labeled mutants also suggest the intactness of binding pocket structure. Kinetic studies of chromophore release monitored by time course fluorescence and quantitative high pressure liquid chromatography analyses show that the ligand release rate is significantly enhanced only in Phe78 mutants. The extent of DNA cleavage in vitro corresponds well to the rate of chromophore release. The results provide the first clear-cut indication of how toxin release can be controlled by a specific side chain of a carrier protein.
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Banerjee B, Mandal SK, Roy SC. Cerium(IV) Ammonium Nitrate-catalyzed Synthesis of β-Keto Enol Ethers from Cyclic β-Diketones and Their Deprotection. CHEM LETT 2006. [DOI: 10.1246/cl.2006.16] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Urbaniak MD, Bingham JP, Hartley JA, Woolfson DN, Caddick S. Design and Synthesis of a Nitrogen Mustard Derivative Stabilized by Apo-neocarzinostatin. J Med Chem 2004; 47:4710-5. [PMID: 15341486 DOI: 10.1021/jm040790d] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neocarzinostatin (NCS) is an antitumor antibiotic comprising a 1:1 protein-chromophore complex and exhibits cytotoxic action through DNA cleavage via H-abstraction. Cytotoxic activity resides with the chromophore 1 alone, while the protein (apoNCS) protects and transports labile 1. The naphthoate portion (2) of NCS chromophore (1) is important for binding to apoNCS and DNA intercalation. In this paper we describe our attempts to use apoNCS to improve the hydrolytic stability of novel bifunctional DNA alkylating agents. The nitrogen mustards, melphalan and chlorambucil, were both conjugated to 2, and the biological activities of these conjugates were assessed. Chlorambucil did not benefit from conjugation. The melphalan conjugate (6) formed covalent DNA adducts at guanine bases and exhibited greater in vitro cytotoxic activity than unmodified melphalan. Fluorescence and NMR spectroscopy showed that 6 binds to apoNCS. Binding to apoNCS-protected 6 reduced the extent of hydrolysis of the conjugate. This novel approach demonstrates for the first time that an enediyne apo-protein can be used to improve the stability of substances that are of potential interest in cancer chemotherapy.
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Affiliation(s)
- Michael D Urbaniak
- Department of Chemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, UK
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Clerici A, Pastori N, Porta O. Mild acetalisation of mono and dicarbonyl compounds catalysed by titanium tetrachloride. Facile synthesis of β-keto enol ethers. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(00)01001-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Toshima K, Takai S, Maeda Y, Takano R, Matsumura S. Chemical Synthesis and DNA Photocleavage of the Intercalator–Carbohydrate Hybrid Moiety of the Neocarzinostatin Chromophore. Angew Chem Int Ed Engl 2000. [DOI: 10.1002/1521-3757(20001016)112:20<3802::aid-ange3802>3.0.co;2-l] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Toshima K, Takai S, Maeda Y, Takano R, Matsumura S. Chemical Synthesis and DNA Photocleavage of the Intercalator-Carbohydrate Hybrid Moiety of the Neocarzinostatin Chromophore This research was partially supported by a Grant-in-Aid for Encouragement of Young Scientists from the Ministry of Education, Science, Sports, and Culture, Japan, and a research grant of Keio University Special Grant-in-Aid for Innovative Collaborative Research Projects. Angew Chem Int Ed Engl 2000; 39:3656-3658. [PMID: 11091429 DOI: 10.1002/1521-3773(20001016)39:20<3656::aid-anie3656>3.0.co;2-o] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- K Toshima
- Department of Applied Chemistry Faculty of Science and Technology Keio University 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)
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Janin YL, Chiki J, Legraverend M, Huel C, Bisagni E. On the methylation of 3-cyano-6-hydroxypyridine-2(1H)-ones. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(99)00755-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Umezawa Y, Nishio M. CH/pi interactions in the crystal structure of class I MHC antigens and their complexes with peptides. Bioorg Med Chem 1998; 6:2507-15. [PMID: 9925306 DOI: 10.1016/s0968-0896(98)80024-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The crystal structure of class I major histocompatibility complex antigens (MHC) bound to their specific ligand peptides were analyzed, in the context of the CH/pi interaction, with use of a computer program CHPI. A number of short CH/Csp2 distances have been shown at the boundary of the heavy chain and beta2 microglobulin. These interactions are conserved between species, human versus murine. A number of contacts shorter than the conventional van der Waals distance have been disclosed between CH hydrogens and aromatic side-chain groups in the MHC/peptide complexes. The CH/pi interaction has been suggested to contribute to the specificity in the complex formation of class I MHC.
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Affiliation(s)
- Y Umezawa
- Institute of Microbial Chemistry, Tokyo, Japan
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Myers AG, Liang J, Hammond M, Harrington PM, Wu Y, Kuo EY. Total Synthesis of (+)-Neocarzinostatin Chromophore. J Am Chem Soc 1998. [DOI: 10.1021/ja980588y] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew G. Myers
- Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena, California 91125
| | - Jun Liang
- Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena, California 91125
| | - Marlys Hammond
- Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena, California 91125
| | - Philip M. Harrington
- Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena, California 91125
| | - Yusheng Wu
- Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena, California 91125
| | - Elaine Y. Kuo
- Division of Chemistry and Chemical Engineering California Institute of Technology Pasadena, California 91125
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Suzuki I, Naoe Y, Bando M, Nemoto H, Shibuya M. pH Dependent cycloaromatization of enediyne model compounds via γ-oxo ketene acetal intermediates. Tetrahedron Lett 1998. [DOI: 10.1016/s0040-4039(98)00200-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Umezawa Y, Nishio M. CH/pi interactions as demonstrated in the crystal structure of guanine-nucleotide binding proteins, Src homology-2 domains and human growth hormone in complex with their specific ligands. Bioorg Med Chem 1998; 6:493-504. [PMID: 9597192 DOI: 10.1016/s0968-0896(98)00002-9] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The CH/pi interaction is a weak attractive molecular force occurring between CH groups and pi-systems. Possibility has been examined for the role of CH/pi interaction, by use of a computer program, in the crystallographic data of several guanine-nucleotide binding proteins, src homology-2 domains and human growth hormone complexed with their specific ligands. Short CH/pi contacts have been found in every case where cohesive forces are expected. Comparison of the structures of functionary related proteins has shown that mutation may occur but necessary CH/pi interactions are conserved. A considerable part of the non-polar interactions, broadly ascribed in the past to the van der Waals interaction or the so-called hydrophobic effect, has been suggested to be attributed to a more specific attractive force, the CH/pi interaction.
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Affiliation(s)
- Y Umezawa
- Institute of Microbial Chemistry, Tokyo, Japan
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Takahashi T, Tanaka H, Yamada H, Matsumoto T, Sugiura Y. Synthese eines neungliedrigen, maskierten Endiin-Analogons mit DNA-intercalierender und DNA-spaltender Aktivität. Angew Chem Int Ed Engl 1997. [DOI: 10.1002/ange.19971091335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Grissom JW, Gunawardena GU, Klingberg D, Huang D. The chemistry of enediynes, enyne allenes and related compounds. Tetrahedron 1996. [DOI: 10.1016/0040-4020(96)00016-6] [Citation(s) in RCA: 307] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Barresi F, Hindsgaul O. Chemically Synthesized Oligosaccharides, 1994. A Searchable Table of Glycosidic Linkages. J Carbohydr Chem 1995. [DOI: 10.1080/07328309508005396] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Nishio M, Umezawa Y, Hirota M, Takeuchi Y. The CH/π interaction: Significance in molecular recognition. Tetrahedron 1995. [DOI: 10.1016/0040-4020(94)01066-9] [Citation(s) in RCA: 514] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Imajo S, Ishiguro M, Tanaka T, Hirama M, Teplyakov A. On the conformation of Phe78 of a chromoprotein antibiotic, neocarzinostatin. Bioorg Med Chem 1995; 3:429-36. [PMID: 8581426 DOI: 10.1016/0968-0896(95)00032-c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A structure of neocarzinostatin, an antitumor chromoprotein antibiotic, has been built using X-ray crystallographic data and NMR data, particularly NOE data observed between the apoprotein and the chromophore. Chemical shift changes of protons of the chromophore upon binding to the apoprotein indicated that the aromatic plane of Phe52 has the conformation almost perpendicular to the C-2-C-3 triple bond of the core of the chromophore while Phe78 takes multiple conformations in solution although one of the stable conformations has been assigned for Phe78 in a crystal structure.
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Affiliation(s)
- S Imajo
- Suntory Institute for Biomedical Research, Osaka, Japan
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