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Elbatrawi YM, Pedretty KP, Giddings N, Woodcock HL, Del Valle JR. δ-Azaproline and Its Oxidized Variants. J Org Chem 2020; 85:4207-4219. [DOI: 10.1021/acs.joc.9b03384] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yassin M. Elbatrawi
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Kyle P. Pedretty
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Nicole Giddings
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - H. Lee Woodcock
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Juan R. Del Valle
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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2
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Dabalos CL, Ohgo K, Kumashiro KK. Detection of Labile Conformations of Elastin’s Prolines by Solid-State Nuclear Magnetic Resonance and Fourier Transform Infrared Techniques. Biochemistry 2019; 58:3848-3860. [DOI: 10.1021/acs.biochem.9b00414] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Chester L. Dabalos
- Department of Chemistry, University of Hawaii, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Kosuke Ohgo
- Department of Chemistry, University of Hawaii, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Kristin K. Kumashiro
- Department of Chemistry, University of Hawaii, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
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3
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Park HS, Kang YK. Which DFT levels of theory are appropriate in predicting the prolyl cis–trans isomerization in solution? NEW J CHEM 2019. [DOI: 10.1039/c9nj02946j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
DFTs were assessed for the conformational preferences of the peptides containing Pro and its derivatives in chloroform and water.
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Affiliation(s)
- Hae Sook Park
- Department of Nursing
- Cheju Halla University
- Cheju 63092
- Republic of Korea
| | - Young Kee Kang
- Department of Chemistry
- Chungbuk National University
- Cheongju
- Republic of Korea
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4
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Dueholm B, Drew DP, Sweetman C, Simonsen HT. In planta and in silico characterization of five sesquiterpene synthases from Vitis vinifera (cv. Shiraz) berries. PLANTA 2019; 249:59-70. [PMID: 30136197 DOI: 10.1007/s00425-018-2986-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 08/13/2018] [Indexed: 05/23/2023]
Abstract
Five Vitis vinifera sesquiterpene synthases were characterized, two was previously uncharacterized, one being a caryophyllene/cubebene synthase and the other a cadinene synthase. Residue differences with other Vitis sesquiterpene synthases are described. The biochemical composition of grape berries at harvest can have a profound effect on the varietal character of the wine produced. Sesquiterpenes are an important class of volatile compounds produced in grapes that contribute to the flavor and aroma of wine, making the elucidation of their biosynthetic origin an important field of research. Five cDNAs corresponding to sesquiterpene synthase genes (TPSs) were isolated from Shiraz berries and expressed in planta in Nicotiana benthamiana followed by chemical characterization by GC-MS. Three of the TPS cDNAs were isolated from immature berries and two were isolated from ripe Shiraz berries. Two of the investigated enzymes, TPS26 and TPS27, have been previously investigated by expression in E. coli, and the in planta products generally correspond to these previous studies. The enzyme TPS07 differed by eight amino acids (none of which are in the active site) from germacrene B and D synthase isolated from Gewürztraminer grapes and characterized in vitro. Here in planta characterization of VvShirazTPS07 yielded ylangene, germacrene D and several minor products. Two of the enzymes isolated from immature berries were previously uncharacterized enzymes. VvShirazTPS-Y1 produced cadinene as a major product and at least 17 minor sesquiterpenoid skeletons. The second, VvShirazTPS-Y2, was characterized as a caryophyllene/cubebene synthase, a combination of products not previously reported from a single enzyme. Using in silico methods, we identified residues that could play key roles regarding differences in product formation of these enzymes. The first ring closure that is either a 1,10- or 1,11-ring closure is likely controlled by three neighboring amino acids in helices G1, H2, and J. As for many other investigated TPS enzymes, we also observe that only a few residues can account for radical changes in product formation.
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Affiliation(s)
- Bjørn Dueholm
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Damian P Drew
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Lyngby, Denmark
- Wine Science, School of Agriculture, Food and Wine, University of Adelaide, Urrbrae, SA, 5064, Australia
| | - Crystal Sweetman
- Wine Science, School of Agriculture, Food and Wine, University of Adelaide, Urrbrae, SA, 5064, Australia
| | - Henrik T Simonsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800, Lyngby, Denmark.
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5
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Lin YJ, Chang CH, Horng JC. The Impact of 4-Thiaproline on Polyproline Conformation. J Phys Chem B 2014; 118:10813-20. [DOI: 10.1021/jp503915p] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yu-Ju Lin
- Department of Chemistry and Frontier Research Center on Fundamental and Applied
Sciences of Matters, National Tsing Hua University, Hsinchu, Taiwan 30013, R.O.C
| | - Chiao-Hsin Chang
- Department of Chemistry and Frontier Research Center on Fundamental and Applied
Sciences of Matters, National Tsing Hua University, Hsinchu, Taiwan 30013, R.O.C
| | - Jia-Cherng Horng
- Department of Chemistry and Frontier Research Center on Fundamental and Applied
Sciences of Matters, National Tsing Hua University, Hsinchu, Taiwan 30013, R.O.C
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6
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Kang YK, Park HS. Conformational preferences of the 2-methylproline residue and its role in stabilizing β-turn and polyproline II structures of peptides. NEW J CHEM 2014. [DOI: 10.1039/c4nj00072b] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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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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8
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Ding Q, Zhang Z, Liu JJ, Jiang N, Zhang J, Ross TM, Chu XJ, Bartkovitz D, Podlaski F, Janson C, Tovar C, Filipovic ZM, Higgins B, Glenn K, Packman K, Vassilev LT, Graves B. Discovery of RG7388, a potent and selective p53-MDM2 inhibitor in clinical development. J Med Chem 2013; 56:5979-83. [PMID: 23808545 DOI: 10.1021/jm400487c] [Citation(s) in RCA: 412] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Restoration of p53 activity by inhibition of the p53-MDM2 interaction has been considered an attractive approach for cancer treatment. However, the hydrophobic protein-protein interaction surface represents a significant challenge for the development of small-molecule inhibitors with desirable pharmacological profiles. RG7112 was the first small-molecule p53-MDM2 inhibitor in clinical development. Here, we report the discovery and characterization of a second generation clinical MDM2 inhibitor, RG7388, with superior potency and selectivity.
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Affiliation(s)
- Qingjie Ding
- Discovery Chemistry, ‡Discovery Technologies, §Discovery Oncology, ∥Non-Clinical Development, Roche Research Center, Hoffmann-La Roche, Inc. , 340 Kingsland Street, Nutley, New Jersey 07110, United States
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9
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Saha I, Shamala N. Investigating proline puckering states in diproline segments in proteins. Biopolymers 2013; 99:605-10. [DOI: 10.1002/bip.22224] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 02/13/2013] [Accepted: 02/15/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Indranil Saha
- Department of Physics; Indian Institute of Science; Bangalore; 560012; Karnataka; India
| | - Narayanaswamy Shamala
- Department of Physics; Indian Institute of Science; Bangalore; 560012; Karnataka; India
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Efficient synthesis of unnatural dipeptides based on cis-2,5-disubstituted pyrrolidine. Amino Acids 2012; 42:2121-7. [DOI: 10.1007/s00726-011-0949-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 05/19/2011] [Indexed: 10/18/2022]
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11
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Feytens D, Chaume G, Chassaing G, Lavielle S, Brigaud T, Byun BJ, Kang YK, Miclet E. Local Control of the Cis–Trans Isomerization and Backbone Dihedral Angles in Peptides Using Trifluoromethylated Pseudoprolines. J Phys Chem B 2012; 116:4069-79. [DOI: 10.1021/jp300284u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Debby Feytens
- Laboratoire des BioMolécules, UPMC Paris 06, 4, Place Jussieu, 75005 Paris, France
- Laboratoire des BioMolécules, Departement de Chimie, Ecole Normale Superieure, 24, rue Lhomond, 75005 Paris, France
- UMR 7203, FR 2569, 4, Place Jussieu, 75005 Paris, France
| | - Grégory Chaume
- Laboratoire SOSCO, Université de Cergy-Pontoise, EA 4505, 5 mail Gay Lussac, 95000 Cergy-Pontoise, France
| | - Gérard Chassaing
- Laboratoire des BioMolécules, UPMC Paris 06, 4, Place Jussieu, 75005 Paris, France
- Laboratoire des BioMolécules, Departement de Chimie, Ecole Normale Superieure, 24, rue Lhomond, 75005 Paris, France
- UMR 7203, FR 2569, 4, Place Jussieu, 75005 Paris, France
| | - Solange Lavielle
- Laboratoire des BioMolécules, UPMC Paris 06, 4, Place Jussieu, 75005 Paris, France
- Laboratoire des BioMolécules, Departement de Chimie, Ecole Normale Superieure, 24, rue Lhomond, 75005 Paris, France
- UMR 7203, FR 2569, 4, Place Jussieu, 75005 Paris, France
| | - Thierry Brigaud
- Laboratoire SOSCO, Université de Cergy-Pontoise, EA 4505, 5 mail Gay Lussac, 95000 Cergy-Pontoise, France
| | - Byung Jin Byun
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
| | - Young Kee Kang
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
| | - Emeric Miclet
- Laboratoire des BioMolécules, UPMC Paris 06, 4, Place Jussieu, 75005 Paris, France
- Laboratoire des BioMolécules, Departement de Chimie, Ecole Normale Superieure, 24, rue Lhomond, 75005 Paris, France
- UMR 7203, FR 2569, 4, Place Jussieu, 75005 Paris, France
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12
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Parasuk W, Parasuk V. Proline- and thioproline-derived enamines: The theoretical study of torsional and ring-puckering conformations. COMPUT THEOR CHEM 2011. [DOI: 10.1016/j.comptc.2010.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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Kumeta Y, Ito M. Characterization of delta-guaiene synthases from cultured cells of Aquilaria, responsible for the formation of the sesquiterpenes in agarwood. PLANT PHYSIOLOGY 2010; 154:1998-2007. [PMID: 20959422 PMCID: PMC2996018 DOI: 10.1104/pp.110.161828] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 10/19/2010] [Indexed: 05/20/2023]
Abstract
The resinous portions of Aquilaria plants, called agarwood, have been used as medicines and incenses. Agarwood contains a great variety of sesquiterpenes, and a study using cultured cells of Aquilaria showed the production of sesquiterpenes (α-guaiene, α-humulene, and δ-guaiene) to be induced by treatment with methyl jasmonate (MJ). In this study, the accumulation and production of sesquiterpenes were quantified. The amounts accumulated and produced reached a maximum at 12 h, and the most abundant product was α-humulene at 6 h and δ-guaiene after 12 h. However, a headspace analysis of the cells revealed that α-humulene is likely to be volatilized; so overall, the most abundant sesquiterpene in the cells was δ-guaiene. A cDNA library from RNA isolated from MJ-treated cells was screened using PCR methodologies to isolate five clones with very similar amino acid sequences. These clones were expressed in Escherichia coli, and enzymatic reactions using farnesyl pyrophosphate revealed that three of the clones yielded the same compounds as extracted from MJ-treated cells, the major product being δ-guaiene. These genes and their encoded enzymes are the first sesquiterpene synthases yielding guaiane-type sesquiterpenes as their major products to be reported. Expression of a fourth terpene synthase gene in bacteria resulted in the accumulation of the protein in insoluble forms. Site-directed mutagenesis of the inactive clone and three-dimensional homology modeling suggested that the structure of the N-terminal domain was important in facilitating proper folding of the protein to form a catalytically active structure.
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14
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Moradi M, Babin V, Roland C, Sagui C. A classical molecular dynamics investigation of the free energy and structure of short polyproline conformers. J Chem Phys 2010; 133:125104. [DOI: 10.1063/1.3481087] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
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15
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Anteunis MJO, Hosten NGC, Borremans FAM, Tavernier DK. Preparation and Conformational Study Of Cis-5-methyl-N1,N4-diacetyl-2-piperazine-N′-methyl-carboxamide. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bscb.19830921109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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16
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Stereochemical aspects of proton chemical shifts. VII-4-fluoro-prolines. A FURTHER CASE OF VIOLATION OF THE “SYN-UPFIELD” RULE IN 1H-NMR. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bscb.19780871109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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Sleeckx JJM, Anteunis MJO. Revisited Conformational Aspects of Pro and Hyp Pyrrolidine Rings In Bicyclic Peptide Systems. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bscb.19850940306] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Frans, Borremans AM, Nachtergaele WA, Budesinsky M, Marc, Anteunis JO, Kozodziejczyk A, Liberek B. Solution Conformation of Cis and Trans N-Acetyl-L-Thiazolidine-4-Carboxylic Acid. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bscb.19800890204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19
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Teklebrhan RB, Zhang K, Schreckenbach G, Schweizer F, Wetmore SD. Intramolecular Hydrogen Bond-Controlled Prolyl Amide Isomerization in Glucosyl 3(S)-Hydroxy-5-hydroxymethylproline Hybrids: A Computational Study. J Phys Chem B 2010; 114:11594-602. [DOI: 10.1021/jp1006186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Robel B. Teklebrhan
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada, Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3A 1R9 Canada, and Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4 Canada
| | - Kaidong Zhang
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada, Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3A 1R9 Canada, and Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4 Canada
| | - G. Schreckenbach
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada, Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3A 1R9 Canada, and Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4 Canada
| | - Frank Schweizer
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada, Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3A 1R9 Canada, and Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4 Canada
| | - Stacey D. Wetmore
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada, Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3A 1R9 Canada, and Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4 Canada
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20
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Zhu H, Blom M, Compagnon I, Rijs AM, Roy S, von Helden G, Schmidt B. Conformations and vibrational spectra of a model tripeptide: change of secondary structure upon micro-solvation. Phys Chem Chem Phys 2010; 12:3415-25. [PMID: 20352678 DOI: 10.1039/b926413b] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mid-infrared (IR) hole burning spectra of the model tripeptide Z-Aib-Pro-NHMe (Z = benzyloxycarbonyl) in gas phase and its micro-clusters with one and two methanol molecules are presented. To establish a relation between experimental spectra and the underlying conformations, calculations at the DFT [B3LYP/6-311++G(d,p)] level of theory are performed. In particular, the intra-peptide and the peptide-methanol hydrogen bonds can be identified from spectral shifts in the amide I, II, and III regions. While the unsolvated tripeptide as well as its one-methanol cluster prefer a gamma-turn structure, a beta-turn structure is found for the two-methanol cluster, in agreement with previous condensed phase studies. Comparison of measured and simulated spectra reveals that the favorable methanol binding sites are at the head and tail parts of the tripeptide. The interconversions between gamma-turn and beta-turn structures are governed by potential barriers below 10 kJ mol(-1) inside one of the low energy basins of the potential energy surface.
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Affiliation(s)
- Hui Zhu
- Institut für Mathematik, Freie Universität Berlin, Arnimallee 6, D-14195 Berlin, Germany.
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21
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Kantharaju, Raghothama S, Aravinda S, Shamala N, Balaram P. Helical conformations of hexapeptides containing N-terminus diproline segments. Biopolymers 2010; 94:360-70. [DOI: 10.1002/bip.21395] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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SOUMA H, KUROSU H, SHOJI A. Precise Structural Analysis of Polypeptides by Quantum Chemical Calculation. KOBUNSHI RONBUNSHU 2010. [DOI: 10.1295/koron.67.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hiroyuki SOUMA
- Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University
| | - Hiromichi KUROSU
- Graduate School of Humanities and Sciences, Nara Women's University
| | - Akira SHOJI
- Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University
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Abstract
The structure of the proline amino acid allows folded polyproline peptides to exist as both left- (PPII) and right-handed (PPI) helices. We have characterized the free energy landscapes of hexamer, nanomer, and tridecamer polyproline peptides in gas phase and implicit water as well as explicit hexane and 1-propanol for the nanomer. To enhance the sampling provided by regular molecular dynamics, we used the recently developed adaptively biased molecular dynamics method, which describes Landau free energy maps in terms of relevant collective variables. These maps, as a function of the collective variables of handedness, radius of gyration, and three others based on the peptide torsion angle omega, were used to determine the relative stability of the different structures, along with an estimate of the transition pathways connecting the different minima. Results show the existence of several metastable isomers and therefore provide a complementary view to experimental conclusions based on photo-induced electron transfer experiments with regard to the existence of stable heterogeneous subpopulations in PPII polyproline.
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Ahmed Z, Myshakina NS, Asher SA. Dependence of the AmII'p proline Raman band on peptide conformation. J Phys Chem B 2009; 113:11252-9. [PMID: 19627094 PMCID: PMC2742972 DOI: 10.1021/jp809857y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We utilized UV resonance Raman (UVRR) measurements and density functional theory (DFT) calculations to relate the AmII'p frequency to the psi angle. The AmII'p frequency shifts by approximately 25 cm(-1) as the psi angle is varied over allowed angles of the Pro peptide bond. The AmII'p frequency does not show any significant dependence on the phi dihedral angle. The conformation sensitivity of the AmII'p frequency derives from conformation-induced changes in the planarity of the Pro peptide bond; psi angle changes push the amide nitrogen out of the peptide bond plane. We use this AmII'p frequency dependence on the psi angle to track temperature-induced conformation changes in a polyproline peptide. The temperature-induced 7 cm(-1) downshift in the AmII'p frequency of the polyproline peptide results from an approximately 45 degrees rotation of the psi dihedral angle from psi = 145 degrees (ideal PPII conformation) to psi = 100 degrees (collapsed PPII conformation).
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Affiliation(s)
- Zeeshan Ahmed
- Department of Chemistry, University of Pittsburgh, PA 15260
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Kang YK, Park HS, Byun BJ. Puckering transitions of pseudoproline residues. Biopolymers 2009; 91:444-55. [DOI: 10.1002/bip.21150] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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26
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Kang YK, Kang NS. Conformational preferences ofN-methoxycarbonyl proline dipeptide. J Comput Chem 2009; 30:1116-27. [DOI: 10.1002/jcc.21136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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LONDON ROBERTE. QUANTITATIVE EVALUATION OF γ-TURN CONFORMATION IN PROLINE-CONTAINING PEPTIDES USING13 C N.M.R. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1979.tb01948.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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BENEDETTI ETTORE, BAVOSO ALFONSO, BLASIO BENEDETTODI, PAVONE VINCENZO, PEDONE CARLO, TONIOLO CLAUDIO, BONORA GIANMARIA. Conformation of linear homo-oligoprolines. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1982.tb00896.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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30
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LONDON ROBERTE, SCHMIDT PAULG, VAVREK RAYMONDJ, STEWART JOHNM. Testing for cis‘ proline with α-aminoisobutyric acid substitution. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1982.tb02612.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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31
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NAGARAJ R, VENKATACHALAPATHI Y, BALARAM P. ROTATIONAL ISOMERISM ABOUT THE Cα-CO BOND IN PROLINE DERIVATIVES. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1980.tb02589.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Chatterjee B, Saha I, Raghothama S, Aravinda S, Rai R, Shamala N, Balaram P. Designed peptides with homochiral and heterochiral diproline templates as conformational constraints. Chemistry 2008; 14:6192-204. [PMID: 18491347 DOI: 10.1002/chem.200702029] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Diproline segments have been advanced as templates for nucleation of folded structure in designed peptides. The conformational space available to homochiral and heterochiral diproline segments has been probed by crystallographic and NMR studies on model peptides containing L-Pro-L-Pro and D-Pro-L-Pro units. Four distinct classes of model peptides have been investigated: a) isolated D-Pro-L-Pro segments which form type II' beta-turn; b) D-Pro-L-Pro-L-Xxx sequences which form type II'-I (betaII'-I, consecutive beta-turns) turns; c) D-Pro-L-Pro-D-Xxx sequences; d) L-Pro-L-Pro-L-Xxx sequences. A total of 17 peptide crystal structures containing diproline segments are reported. Peptides of the type Piv-D-Pro-L-Pro-L-Xxx-NHMe are conformationally homogeneous, adopting consecutive beta-turn conformations. Peptides in the series Piv-D-Pro-L-Pro-D-Xxx-NHMe and Piv-L-Pro-L-Pro-L-Xxx-NHMe, display a heterogeneity of structures in crystals. A type VIa beta-turn conformation is characterized in Piv-L-Pro-L-Pro-L-Phe-OMe (18), while an example of a 5-->1 hydrogen bonded alpha-turn is observed in crystals of Piv-D-Pro-L-Pro-D-Ala-NHMe (11). An analysis of pyrrolidine conformations suggests a preferred proline puckering geometry is favored only in the case of heterochiral diproline segments. Solution NMR studies, reveal a strong conformational influence of the C-terminal Xxx residues on the structures of diproline segments. In L-Pro-L-Pro-L-Xxx sequences, the Xxx residues strongly determine the population of Pro-Pro cis conformers, with an overwhelming population of the trans form in L-Xxx=L-Ala (19).
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Affiliation(s)
- Bhaswati Chatterjee
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
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A matrix isolation study on Ac–l-Pro–NH2: a frequent structural element of β- and γ-turns of peptides and proteins. Tetrahedron 2008. [DOI: 10.1016/j.tet.2007.12.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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34
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Kang YK, Park HS. Conformational Preferences of Pseudoproline Residues. J Phys Chem B 2007; 111:12551-62. [DOI: 10.1021/jp074128f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Young Kee Kang
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea, and Department of Radiotechnology, Cheju-halla College, Cheju 690-708, Republic of Korea
| | - Hae Sook Park
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea, and Department of Radiotechnology, Cheju-halla College, Cheju 690-708, Republic of Korea
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35
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Abstract
The puckering transition of the proline residue with trans and cis prolyl peptide bonds was explored by optimizations along the torsion angle chi1 of the prolyl ring using quantum-chemical methods in water. By analyzing the potential energy surfaces and local minima in water, it is observed that the puckering transition of the proline residue proceeds from a down-puckered conformation to an up-puckered one and vice versa through the transition state with an envelope form having the N atom at the top of the envelope and not a planar one, as seen in the gas phase, although the backbone conformations are different in the gas phase and in water. The barriers to the puckering transition DeltaGup-->down are estimated to be 3.12 and 3.00 kcal/mol for trans and cis conformers at the B3LYP/6-311++G(d,p) level of theory in water, respectively, which are about 1.7 kcal/mol higher than those in the gas phase. Out of 2197 prolines from the 241 high-resolution PDB chains, four transition-state-like structures with the envelope ring puckering are identified. Three of them have the trans prolyl peptide bonds and one has the cis one. The favorable or steric interactions by neighboring residues may be responsible for the stabilization of these transition-state-like ring structures in the proteins.
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Affiliation(s)
- Young Kee Kang
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea.
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36
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Owens NW, Braun C, Schweizer F. Tuning of the Prolyl trans/cis-Amide Rotamer Population by Use of C-Glucosylproline Hybrids. J Org Chem 2007; 72:4635-43. [PMID: 17536863 DOI: 10.1021/jo0700833] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We describe the synthesis of a fused bicyclic C-glucosylproline hybrid (GlcProH) from commercially available 2,3,4,6-tetra-O-benzyl-d-glucopyranose. The GlcProH was incorporated into the model peptides Ac-GlcProH-NHMe and Ac-Gly-GlcProH-NHMe. Postsynthetic modifications can be introduced via derivatization of the carbohydrate scaffold. Conformational analysis of the GlcProH-modified model peptides shows that while the conformation of GlcProH remains fixed, the prolyl N-terminal amide equilibrium (Kt/c) can be varied with different modifications of the carbohydrate scaffold. Simple N-acyl derivatives studied by NMR spectroscopy showed that in CD3OD there was an increase in the cis-amide content as the sugar substituents changed from benzyl (10%) to hydroxyl (22%) to acetate (36%). Similar effects were observed in DMSO-d6. The exact nature of the influence is unclear, but it most likely arises through intramolecular interactions between sugar groups and the peptidic amide backbone. Overall, our GlcProH demonstrates variation in Kt/c through tuning of the carbohydrate scaffold: a new concept in proline peptidomimetics.
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Affiliation(s)
- Neil W Owens
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
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37
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Donnini S, Groenhof G, Wierenga RK, Juffer AH. The planar conformation of a strained proline ring: a QM/MM study. Proteins 2006; 64:700-10. [PMID: 16741995 DOI: 10.1002/prot.21006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
QM and QM/MM energy calculations have been carried out on an atomic resolution structure of liganded triosephosphate isomerase (TIM) that has an active site proline (Pro168) in a planar conformation. The origin of the planarity of this proline has been identified. Steric interactions between the atoms of the proline ring and a tyrosine ring (Tyr166) on one side of the proline prevent the ring from adopting the up pucker (chi1 is approximately -30 degrees), while the side chain of a nearby alanine (Ala171) forbids the down pucker (chi1 is approximately +30 degrees). To obtain a proline conformation that is in agreement with the experimentally observed planar state, a quantum system of sufficient size is required and should at least include the nearby side chains of Tyr166, Ala171, and Glu129 to provide enough stabilization. It is argued that the current force fields for structure optimization do not describe strained protein fragments correctly. The proline is part of a catalytic loop that closes upon ligand binding. Comparison of the proline conformation in different TIM X-ray structures, indicates that in the closed conformation of TIM the proline is planar or nearly planar, while in the open conformation it is down puckered. This suggests that the planarity possibly plays a role in the overall catalytic cycle of TIM, presumable acting as a reservoir of energy that becomes available upon loop opening.
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Affiliation(s)
- Serena Donnini
- The Biocenter and the Department of Biochemistry, University of Oulu, FIN-90014 University of Oulu, Finland
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38
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Abstract
A conformational study on the terminally blocked proline oligopeptides, Ac-(Pro)(n)()-NMe(2) (n = 2-5), is carried out using the ab initio Hartree-Fock level of theory with the self-consistent reaction field method in the gas phase and in solutions (chloroform, 1-propanol, and water) to explore the preference and transition between polyproline II (PPII) and polyproline I (PPI) conformations depending on the chain length, the puckering, and the solvent. The mean differences in the free energy per proline of the up-puckered conformations relative to the down-puckered conformations for both diproline and triproline increases for the PPII-like conformations and decreases for the PPI-like conformations as the solvent polarity increases. These calculated results indicate that the PPII-like structures have preferentially all-down puckerings in solutions, whereas the PPI-like structures have partially mixed puckerings. The free energy difference per proline residue between the PPII- and PPI-like structures decreases as the proline chain becomes longer in the gas phase but increases as the proline chain becomes longer in solutions and the solvent polarity increases. In particular, our calculated results indicate that each of the proline oligopeptides can exist as an ensemble of conformations with the trans and cis peptide bonds in solutions, although the PPII-like structure with all-trans peptide bonds is dominantly preferred, which is reasonably consistent with the previously observed results. In diproline Ac-(Pro)(2)-NMe(2), the rotational barrier to the cis-to-trans isomerization for the first prolyl peptide bond increases as the solvent polarity increases, whereas the rotational barrier for the second prolyl peptide bond does not show the monotonic increase as the solvent polarity increases. When the rotational barriers for these two prolyl peptide bonds were compared, it could be deduced that the conformational transition from PPI with the cis peptide bond to PPII with the trans peptide bond is initiated at the C-terminus and proceeds to the N-terminus in water. This is consistent with the results from NMR experiments on polyproline in D(2)O but opposite to the results from enzymatic hydrolysis kinetics experiments on polyproline.
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Affiliation(s)
- Young Kee Kang
- Department of Chemistry and Basic Science Research Institute, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
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Abstract
The beta-turn is a common motif in both proteins and peptides and often a recognition site in protein interactions. A beta-turn of four sequential residues reverses the direction of the peptide chain and is classified by the phi and psi backbone torsional angles of residues i + 1 and i + 2. The type VI turn usually contains a proline with a cis-amide bond at residue i + 2. Cis-proline analogs that constrain the peptide to adopt a type VI turn led to peptidomimetics with enhanced activity or metabolic stability. To compare the impact of different analogs on amide cis-trans isomerism and peptide conformation, the conformational preference for the cis-amide bond and the type VI turn was investigated at the MP2/6-31+G** level of theory in water (polarizable continuum water model). Analogs stabilize the cis-amide conformations through different mechanisms: (1) 5-alkylproline, with bulky hydrocarbon substituent on the C(delta) of proline, increases the cis-amide population through steric hindrance between the alkyl substituent and the N-terminal residues; (2) oxaproline or thioproline, the oxazolidine- or thiazolidine-derived proline analog, favors interactions between the dipole of the heterocyclic ring and the preceding carbonyl oxygen; and (3) azaproline, containing a nitrogen atom in place of the C(alpha) of proline, prefers the cis-amide bond by lone-pair repulsion between the alpha-nitrogen and the preceding carbonyl oxygen. Preference for the cis conformation was augmented by combining different modifications within a single proline. Azaproline and its derivatives are most effective in stabilizing cis-amide bonds without introducing additional steric bulk to compromise receptor interactions.
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Affiliation(s)
- Ye Che
- Center for Computational Biology and Department of Biochemistry and Molecular Biophysics, Washington University, St. Louis, MO 63110, USA
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Kee Kang Y, Sook Park H. Ab initio conformational study of N-acetyl-L-proline-N',N'-dimethylamide: a model for polyproline. Biophys Chem 2006; 113:93-101. [PMID: 15617814 DOI: 10.1016/j.bpc.2004.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2004] [Revised: 08/04/2004] [Accepted: 08/06/2004] [Indexed: 11/29/2022]
Abstract
We report here the results on N-acetyl-l-proline-N',N'-dimethylamide (Ac-Pro-NMe2) as a model for polyproline at the HF/6-31+G(d) level with the conductor-like polarizable continuum model of self-consistent reaction field methods to figure out the conformational preference and cis-trans isomerization of polyproline in the gas phase, chloroform, methanol, and water. The second methyl substitution at the carboxyl amide end results in different backbone structures and their populations from those of N-acetyl-L-proline-N-methylamide (Ac-Pro-NHMe). In particular, all conformations with the C7 hydrogen bond between acetyl and amide ends, which is the most probable conformations of Ac-Pro-NHMe in the gas phase and in nonpolar solvents, disappeared for Ac-Pro-NMe2 even in the gas phase due to the lack of amide hydrogen. The dominant conformation for Ac-Pro-NMe2 is the polyproline II structure with the trans prolyl peptide bond in the gas phase and in solutions. In methanol, the population of the polyproline I structure with the cis prolyl peptide bond is calculated to be larger than that in water, which is consistent with experiments. It should be noted that Ac-Pro-NMe2 has higher rotational barriers for the cis-trans isomerization of the Ac-Pro peptide bond than Ac-Pro-NHMe in the gas phase and in solutions, which could be due to the lack of the intramolecular hydrogen bond between prolyl nitrogen and carboxyl N-H group for the transition state of Ac-Pro-NMe2. The rotational barriers for Ac-Pro-NMe2 are increased with the increase of solvent polarity, as seen for Ac-Pro-NHMe.
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Affiliation(s)
- Young Kee Kang
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea.
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41
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Abstract
The puckering transition of 4-substituted proline residues by electron-withdrawing groups, i.e., 4(R)-hydroxy-L-proline (Hyp) and 4(R)-fluoro-L-proline (Flp) residues, with trans and cis prolyl peptide bonds was studied by adiabatic optimizations along the torsion angle chi1 of the prolyl ring at the HF/6-31+G(d) level. By analyzing the potential energy surface and local minima, it is observed that the puckering transition of the prolyl ring for Hyp and Flp residues proceeds from a down-puckered conformation to an up-puckered one through the transition state with an envelope form having the N atom at the top of envelope and not a planar one for both trans and cis conformers, which is the same as found for the unsubstituted proline residue. At HF/6-31+G(d) and B3LYP/6-311++G(d,p) levels, the structures of the backbone and prolyl ring for local minima of Ac-Hyp-NHMe and Ac-Flp-NHMe are quite similar to those of Ac-Pro-NHMe. However, the relative stability of the up-puckered conformation to the down-puckered one is increased for Ac-Hyp-NHMe with the cis imide bond and for Ac-Flp-NHMe with the trans and cis imide bonds. In particular, the 4(R)-substitution by hydroxy and fluorine groups has brought some structural changes in the prolyl ring of the transition states and the changes in barriers for the puckering transition. The puckering transitions for Ac-Hyp-NHMe and Ac-Flp-NHMe are proven to be predominantly electronically driven by analyzing the electronic and enthalpic contributions to the barriers, as seen for Ac-Pro-NHMe.
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Affiliation(s)
- Il Keun Song
- Department of Chemistry and Basic Science Research Institute, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea
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43
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Kang YK, Choi HY. Cis–trans isomerization and puckering of proline residue. Biophys Chem 2004; 111:135-42. [PMID: 15381311 DOI: 10.1016/j.bpc.2004.05.006] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Revised: 05/16/2004] [Accepted: 05/17/2004] [Indexed: 11/19/2022]
Abstract
We report here the results on N-acetyl-L-proline-N'-methylamide (Ac-Pro-NHMe) calculated at the HF/6-31+G(d) level with the conductor-like polarizable continuum model (CPCM) of self-consistent reaction field methods to investigate the changes of backbone and prolyl ring along the cis-trans isomerization of the prolyl peptide bond. From the potential energy surface, the barrier to ring flip from the down-puckered conformation to the up-puckered one is estimated to be 2.5 and 3.2 kcal/mol for trans and cis conformers of Ac-Pro-NHMe, respectively. In particular, the ring flip seems to be inaccessible in the intermediate regions between trans and cis conformations, because of higher barriers (approximately 13-19 kcal/mol) to rotation of the prolyl peptide bond. The torsion angles for backbone and prolyl ring vary largely around the transition states at omega' approximately 120 degrees and -70 degrees for the prolyl peptide bond. Three kinds of puckering amplitudes show the same trend of puckering along the cis-trans isomerization although their absolute values are different. In particular, trans and cis conformations have the almost same degree of puckering. The cis populations and barriers to rotation of the prolyl peptide bond for Ac-Pro-NHMe are increased with the increase of solvent polarity, which is mainly ascribed to the decreases of relative free energies for cis conformations and the increase of relative free energies for transition states.
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Affiliation(s)
- Young Kee Kang
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea.
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44
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Kang YK. Ring Flip of Proline Residue via the Transition State with an Envelope Conformation. J Phys Chem B 2004. [DOI: 10.1021/jp049658f] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Young Kee Kang
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea
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45
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46
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Rankin KN, Boyd RJ. A Computational Study of the Isomerization of Prolyl Amides As Catalyzed by Intramolecular Hydrogen Bonding. J Phys Chem A 2002. [DOI: 10.1021/jp020846k] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kathryn N. Rankin
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3
| | - Russell J. Boyd
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3
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47
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Comparative conformational study of N-acetyl-N′-methylprolineamide with different basis sets. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0166-1280(02)00077-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Benzi C, Improta R, Scalmani G, Barone V. Quantum mechanical study of the conformational behavior of proline and 4R-hydroxyproline dipeptide analogues in vacuum and in aqueous solution. J Comput Chem 2002; 23:341-50. [PMID: 11908497 DOI: 10.1002/jcc.10015] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The conformational behavior of the title compounds has been investigated by Hartree-Fock, MP2, and DFT computations on the most significant structures related to variations of the backbone dihedral angles, cis/trans isomerism around the peptide bond, and diastereoisomeric puckering of the pyrrolidine ring. In vacuum the reversed gamma turn (gammal), characterized by an intramolecular hydrogen bridge, corresponds to the absolute energy minimum for both puckerings (up and down) of the pyrrolidine ring. An additional energy minimum is found in the helix region, but only for an up puckering of the pyrrolidine ring. When solvent effects are included by means of the polarizable continuum model the conformer observed experimentally in condensed phases becomes the absolute minimum. The down puckering is always favored over its up counterpart, albeit by different amounts (0.4-0.5 kcal/mol for helical structures and about 2 kcal/mol for gammal structures). In helical structures cis arrangements of the peptide bond are only slightly less stable than their trans counterparts. This is no longer true for gammal structures, because the formation of an intramolecular hydrogen bond is possible only for trans peptide bonds. In most cases, proline and hydroxyproline show the same general trends; however, the electronegative 4(R) substituent of hydroxyproline leads to a strong preference for up puckerings irrespective of the backbone conformation.
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Affiliation(s)
- Caterina Benzi
- Dipartimento di Chimica Universita' Federico II, Complesso Universitario di Monte S. Angelo, Napoli, Italy
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49
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Affiliation(s)
- Young Kee Kang
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea
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50
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Puliti R, Mattia C, Giancola C, Barone G. Crystal structure and conformational stability of N -acetyl- l -prolyl- l -leucinamide. Comparison between structural and thermophysical data. J Mol Struct 2000. [DOI: 10.1016/s0022-2860(00)00537-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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