1
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Hu Z, Lin G, Sender M, Cannon KC, Davis FA, Krow GR. C6-Substituted methanopyrrolidine β-amino acid: synthesis and characterization of oligomeric foldamers. Tetrahedron Lett 2020. [DOI: 10.1016/j.tetlet.2020.152240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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2
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Chingle R, Mulumba M, Chung NN, Nguyen TMD, Ong H, Ballet S, Schiller PW, Lubell WD. Solid-Phase Azopeptide Diels–Alder Chemistry for Aza-pipecolyl Residue Synthesis To Study Peptide Conformation. J Org Chem 2019; 84:6006-6016. [DOI: 10.1021/acs.joc.8b03283] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
| | | | - Nga N. Chung
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montréal, Québec H2W 1R7, Canada
| | - Thi M.-D. Nguyen
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montréal, Québec H2W 1R7, Canada
| | | | - Steven Ballet
- Research Group of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Peter W. Schiller
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montréal, Québec H2W 1R7, Canada
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3
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Abstract
The neurohypophyseal hormone oxytocin (OT) and related modulators of the oxytocin receptor (OTR) have been the subject of intensive research for nearly seven decades. Despite having rather poor drug-like properties, OT is used as a treatment for labor induction, postpartum hemorrhage, and lactation support. The potential use of OT in the treatment of central nervous system (CNS)-related diseases has recently renewed interest in the pharmacology of OT. Oxytocin is one of the most extensively studied cyclic peptides and since the elucidation of its structure in 1953 thousands of peptidic OT analogs with antagonistic and agonistic properties have been synthesized and biologically evaluated. Among them are atosiban, a mixed oxytocin receptor (OTR)/vasopressin 1a receptor (V1aR) antagonist used as a tocolytic agent approved (in certain countries), and carbetocin, a longer acting OTR agonist on the market for the treatment of postpartum hemorrhage. Many other OT analogs with improved pharmacological properties (e.g., barusiban, Antag III) have been identified. These peptides have been tested in clinical trials and/or used as pharmacological tools. In this chapter, the modifications of the OT molecule that led to the discovery of these compounds are reviewed.
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4
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Rodríguez I, Calaza MI, Jiménez AI, Cativiela C. Synthesis of enantiomerically pure δ-benzylproline derivatives. NEW J CHEM 2015. [DOI: 10.1039/c4nj01894j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The methodology allows for the preparation of enantiopure δ-substituted l-proline analogues bearing the side chain of proteinogenic residues.
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Affiliation(s)
- Isabel Rodríguez
- Departamento de Química Orgánica
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC–Universidad de Zaragoza
- 50009 Zaragoza
- Spain
| | - M. Isabel Calaza
- Departamento de Química Orgánica
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC–Universidad de Zaragoza
- 50009 Zaragoza
- Spain
| | - Ana I. Jiménez
- Departamento de Química Orgánica
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC–Universidad de Zaragoza
- 50009 Zaragoza
- Spain
| | - Carlos Cativiela
- Departamento de Química Orgánica
- Instituto de Síntesis Química y Catálisis Homogénea (ISQCH)
- CSIC–Universidad de Zaragoza
- 50009 Zaragoza
- Spain
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5
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Wiśniewski K, Alagarsamy S, Galyean R, Tariga H, Thompson D, Ly B, Wiśniewska H, Qi S, Croston G, Laporte R, Rivière PJM, Schteingart CD. New, Potent, and Selective Peptidic Oxytocin Receptor Agonists. J Med Chem 2014; 57:5306-17. [DOI: 10.1021/jm500365s] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Kazimierz Wiśniewski
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Sudarkodi Alagarsamy
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Robert Galyean
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Hiroe Tariga
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Dorain Thompson
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Brian Ly
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Halina Wiśniewska
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Steve Qi
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Glenn Croston
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Regent Laporte
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Pierre J.-M. Rivière
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
| | - Claudio D. Schteingart
- Ferring Research Institute Inc., 4245 Sorrento Valley Boulevard, San Diego, California 92121, United States
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6
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Abstract
The reaction of thioamino acids and N-terminal peptides, mediated by hindered isonitriles and hydroxybenzotriazole, gives rise to peptide bonds. In one pathway, oxytocin was synthesized by eight such reiterative amidations. In another stereospecific track, oxytocin was constructed by native chemical ligation, wherein the two building blocks were assembled by thioacid amine amidation. The NMR spectra of oxytocin and dihydrooxytocin suggest a high level of preorganization in the latter, perhaps favoring oxidative folding.
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Affiliation(s)
- Ting Wang
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, NY 10065
| | - Samuel J. Danishefsky
- Laboratory for Bioorganic Chemistry, Sloan-Kettering Institute for Cancer Research, 1275 York Avenue, New York, NY 10065
- Department of Chemistry, Columbia University, Havemeyer Hall, 3000 Broadway, New York, NY 10027
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7
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Hosoya M, Otani Y, Kawahata M, Yamaguchi K, Ohwada T. Water-Stable Helical Structure of Tertiary Amides of Bicyclic β-Amino Acid Bearing 7-Azabicyclo[2.2.1]heptane. Full Control of Amide Cis−Trans Equilibrium by Bridgehead Substitution. J Am Chem Soc 2010; 132:14780-9. [DOI: 10.1021/ja1017877] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Masahiro Hosoya
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
| | - Yuko Otani
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
| | - Masatoshi Kawahata
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
| | - Kentaro Yamaguchi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
| | - Tomohiko Ohwada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan, and Department of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan
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8
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Synthesis of allose-templated hydroxyornithine and hydroxyarginine analogs. Carbohydr Res 2010; 345:1533-40. [DOI: 10.1016/j.carres.2010.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 04/05/2010] [Accepted: 04/19/2010] [Indexed: 11/19/2022]
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9
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Spyranti Z, Fragiadaki M, Magafa V, Borovickova L, Spyroulias GA, Cordopatis P, Slaninova J. In position 7 l- and d-Tic-substituted oxytocin and deamino oxytocin: NMR study and conformational insights. Amino Acids 2010; 39:539-48. [DOI: 10.1007/s00726-009-0470-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Accepted: 12/29/2009] [Indexed: 11/28/2022]
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10
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Zhang K, Schweizer F. Design and synthesis of glucose-templated proline–lysine chimera: polyfunctional amino acid chimera with high prolyl cis amide rotamer population. Carbohydr Res 2009; 344:576-85. [DOI: 10.1016/j.carres.2008.12.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 12/17/2008] [Accepted: 12/28/2008] [Indexed: 11/16/2022]
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11
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Fragiadaki M, Magafa V, Borovicková L, Slaninová J, Cordopatis P. Synthesis and biological activity of oxytocin analogues containing conformationally-restricted residues in position 7. Eur J Med Chem 2007; 42:799-806. [PMID: 17316912 DOI: 10.1016/j.ejmech.2006.12.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 11/21/2006] [Accepted: 12/12/2006] [Indexed: 10/23/2022]
Abstract
We report the solid-phase synthesis and some pharmacological properties of twenty oxytocin (OT) analogues. Basic modifications at position 7 (introduction of alpha-aminoisobutyric acid [Aib], L- or D-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid [L/D-Tic], L-alpha-t-butylglycine [Gly(Bu(t))] and pipecolic acid [Pip]) were combined with D-Tyr(Et)(2), L/D-(pEt)Phe(2), D-Tic(2), and Mpa(1) modifications and their various combinations in a total of 14 analogues. Additionally, two analogues having one more modification in position 3, i.e. Gly(Bu(t)), and three analogues having glycine in position 9 substituted by d-Tic or Aib, were prepared. The analogues were tested for rat uterotonic activity in vitro, in the rat pressor assay and for binding affinity to human OT receptor. The analogue having the highest antioxytocic activity was [Mpa(1), D-Tyr(Et)(2), D-Tic(7), Aib(9)]OT having pA(2)=8.31+/-0.19; this analogue was also selective.
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Affiliation(s)
- Maria Fragiadaki
- Department of Pharmacy, Laboratory of Pharmacognosy and Chemistry of Natural Products, University of Patras, GR-26500 Patras, Hellas, Greece
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12
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Vartak AP, Johnson RL. Concerted synthesis of a spirobicyclic type-VI beta-turn mimic of Pro-Pro-Pro-NH2. Org Lett 2006; 8:983-6. [PMID: 16494490 PMCID: PMC2597554 DOI: 10.1021/ol0600335] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A highly concerted strategy for the synthesis of symmetrical type-VI beta-turn mimics was formulated. A proof of concept is presented in the synthesis of a spirobicyclic peptidomimetic of Pro-Pro-Pro-NH2, compound 6. The formation of an unusual adduct that was encountered in the process also is reported. This approach is potentially general for type-VI beta-turn mimics where the i+1 and i+2 residues are identical.
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13
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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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14
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Meng HY, Thomas KM, Lee AE, Zondlo NJ. Effects of i and i+3 residue identity on cis-trans isomerism of the aromatic(i+1)-prolyl(i+2) amide bond: implications for type VI beta-turn formation. Biopolymers 2006; 84:192-204. [PMID: 16208767 DOI: 10.1002/bip.20382] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cis-trans isomerization of amide bonds plays critical roles in protein molecular recognition, protein folding, protein misfolding, and disease. Aromatic-proline sequences are particularly prone to exhibit cis amide bonds. The roles of residues adjacent to a tyrosine-proline residue pair on cis-trans isomerism were examined. A short series of peptides XYPZ was synthesized and cis-trans isomerism was analyzed. Based on these initial studies, a series of peptides XYPN, X = all 20 canonical amino acids, was synthesized and analyzed by NMR for i residue effects on cis-trans isomerization. The following effects were observed: (a) aromatic residues immediately preceding Tyr-Pro disfavor cis amide bonds, with K(trans/cis)= 5.7-8.0, W > Y > F; (b) proline residues preceding Tyr-Pro lead to multiple species, exhibiting cis-trans isomerization of either or both X-Pro amide bonds; and (c) other residues exhibit similar values of K(trans/cis) (= 2.9-4.2), with Thr and protonated His exhibiting the highest fraction cis. beta-Branched and short polar residues were somewhat more favorable in stabilizing the cis conformation. Phosphorylation of serine at the i position modestly increases the stability of the cis conformer. In addition, the effect of the i+3 residue was examined in a limited series of peptides TYPZ. NMR data indicated that aromatic residues, Pro, Asn, Ala, and Val at the i+3 residue all favor cis amide bonds, with aromatic residues and Asn favoring more compact phi at Tyr(cis) and Ala and Pro favoring more extended phi at Tyr(cis). D-Alanine at the i+3 position particularly disfavors cis amide bonds.
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Affiliation(s)
- Hai Yun Meng
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
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15
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Aubry C, Oulyadi H, Dutheuil G, Leprince J, Vaudry H, Pannecoucke X, Quirion JC. New synthesis ofcis 5-tert-butyl-L-proline via cuprate. Evaluation as acis proline mimetic in a biological active octapeptide. J Pept Sci 2006; 12:154-60. [PMID: 16138385 DOI: 10.1002/psc.690] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
cis 5-tert-butyl-L-proline (Cbp) was prepared rapidly and efficiently by the addition of low-valent tert-butyl cuprate to an aminal derived from proline. [Cbp(2), D-Leu(5)]-OP was then synthesized, showing a predominant cis peptide bond conformation, as confirmed by NMR.
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Affiliation(s)
- Carine Aubry
- Laboratoire d'Hétérochimie Organique, UMR CNRS 6014, IRCOF, INSA et Université de Rouen, F-76821 Mont-Saint-Aignan, France
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16
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Wittelsberger A, Patiny L, Slaninova J, Barberis C, Mutter M. Introduction of a cis-Prolyl Mimic in Position 7 of the Peptide Hormone Oxytocin Does Not Result in Antagonistic Activity. J Med Chem 2005; 48:6553-62. [PMID: 16220972 DOI: 10.1021/jm049205z] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New insights into the structure-activity relationship of the peptide hormone oxytocin are presented. Incorporation of the novel cis-prolyl mimic 2,2-dimethyl-1,3-thiazolidine-4-carboxylic acid (pseudoproline, PsiPro) at position 7 of the hormone yielded the analogue [Cys(Psi(Me,Me)pro)]7oxytocin (1) that showed a 92-95% induction of the cis peptide bond conformation between Cys6 and PsiPro7, as determined by one- and two-dimensional NMR spectra in water and in DMSO-d6. The impact of the dimethyl moiety regarding conformation and bioactivity was investigated by the synthesis of the corresponding dihydro compound, [Cys(Psi(H,H)pro)]7oxytocin (2). Biological tests of the uterotonic activity, the pressor activity, and the binding affinity to the rat and human oxytocin receptors were carried out. As a most significant result, no antagonistic activities were found for both the cis-constrained analogue 1 and analogue 2, suggesting that a cis conformation between residues 6 and 7 of the molecule does not result in antagonistic activity. However, the about 10-fold reduction in agonistic activity of 1 as compared to oxytocin is consistent with the reduction of the trans conformation from 90% for oxytocin to 5-8% for compound 1. Compound 1 retained a high binding affinity for the oxytocin receptor, with K(i) values of 8.0 and 1.9 nM for the rat and the human receptor, respectively. The correlation between the biological activities and the cis contents obtained from NMR analysis for compounds 1, 2, and oxytocin leads to the hypothesis that a cis/trans conformational change plays an important role in oxytocin receptor binding and activation.
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Affiliation(s)
- Angela Wittelsberger
- Institute of Chemical Sciences and Engineering, Swiss Federal Institute of Technology, EPFL-BCH, CH-1015 Lausanne, Switzerland.
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17
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Wallén EAA, Christiaans JAM, Saarinen TJ, Jarho EM, Forsberg MM, Venäläinen JI, Männistö PT, Gynther J. Conformationally rigid N-acyl-5-alkyl-L-prolyl-pyrrolidines as prolyl oligopeptidase inhibitors. Bioorg Med Chem 2003; 11:3611-9. [PMID: 12901906 DOI: 10.1016/s0968-0896(03)00363-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the N-acyl-L-prolyl-pyrrolidine type of prolyl oligopeptidase inhibitors the L-prolyl group was replaced by different 5-alkyl-L-prolyl groups, resulting in a series of N-acyl-5-alkyl-L-prolyl-pyrrolidines. Since N-amides of 5-alkyl-L-prolines are conformationally more rigid than those of L-proline, the main objective was to make more rigid prolyl oligopeptidase inhibitors. In the series of compounds where the N-acyl group was a Boc group, the 5(R)-tert-butyl group increased the potency strongly. A similar effect was not observed for the 5(S)-tert-butyl group. In the series of compounds where the N-acyl group was a 4-phenylbutanoyl group, the 5(R)-tert-butyl, 5(R)-methyl and 5(S)-methyl groups did not have an effect on the potency [the 5(S)-tert-butyl group was not tested in this series]. As an additional effect, the 5-tert-butyl groups increased the log P of the compounds 1.5 log units, which might be beneficial when targeting the compounds to the brain.
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Affiliation(s)
- Erik A A Wallén
- Department of Pharmaceutical Chemistry, University of Kuopio, PO Box 1627, FIN-70211, Kuopio, Finland.
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18
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Dugave C, Demange L. Cis-trans isomerization of organic molecules and biomolecules: implications and applications. Chem Rev 2003; 103:2475-532. [PMID: 12848578 DOI: 10.1021/cr0104375] [Citation(s) in RCA: 753] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Christophe Dugave
- CEA/Saclay, Département d'Ingénierie et d'Etudes des Protéines (DIEP), Bâtiment 152, 91191 Gif-sur-Yvette, France.
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19
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The stereochemical course of addition of allyltrimethylsilane to protected l-alaninals and l-serinals in the presence of Lewis acids. Total synthesis of cis-(2R,3S)-3-hydroxyproline. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0957-4166(02)00255-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Halab L, Lubell WD. Effect of sequence on peptide geometry in 5-tert-butylprolyl type VI beta-turn mimics. J Am Chem Soc 2002; 124:2474-84. [PMID: 11890796 DOI: 10.1021/ja012442w] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The influence of sequence on turn geometry was examined by incorporating (2S,5R)-5-tert-butylproline (5-(t)BuPro) into a series of dipeptides and tetrapeptides. (2S,5R)-5-tert-Butylproline and proline were respectively introduced at the C-terminal residue of N-acetyl dipeptide N'-methylamides 1 and 2. The conformational analysis of these analogues was performed using NMR and CD spectroscopy as well as X-ray diffraction to examine the factors that control the prolyl amide (in this text, the term "prolyl amide" refers to the tertiary amide composed of the pyrrolidine nitrogen of the prolyl residue and the carbonyl of the N-terminal residue) equilibrium and stabilize type VI beta-turn conformation. The high cis-isomer population with aromatic residues N-terminal to proline was shown to result from a stacking interaction between the partial positive charged prolyl amide nitrogen and the aromatic pi-system as seen in the crystal structure of 1c. The effect of sequence on the prolyl amide equilibrium of 5-(t)BuPro-tetrapeptides (Ac-Xaa-Yaa-5-(t)BuPro-Zaa-XMe, 13 and 14) was studied by varying the amino acids at the Xaa, Yaa, and Zaa positions. High (>80%) cis-isomer populations were obtained with alkyl groups at the Xaa position, an aromatic residue at the Yaa position, and either an alanine or a lysine residue at the Zaa position of the 5-(t)BuPro-tetrapeptide methyl esters in water. Tetrapeptides Ac-Ala-Phe-5-(t)BuPro-Zaa-OMe (Zaa = Ala, Lys), 14d and 14f, with high cis-isomer content adopted type VIa beta-turn conformations as shown by their NMR and CD spectra. Although a pattern of amide proton temperature coefficient values indicative of a hairpin geometry was observed in peptides 14d and 14f, the value magnitudes did not indicate strong hydrogen bonding in water.
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Affiliation(s)
- Liliane Halab
- Département de chimie, Université de Montréal, C. P. 6128, Succursale Centre Ville, Montréal, Québec, Canada H3C 3J7
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21
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Bélec L, Maletinska L, Slaninová J, Lubell WD. The influence of steric interactions on the conformation and biology of oxytocin. Synthesis and analysis of penicillamine(6)-oxytocin and penicillamine(6)-5-tert-butylproline(7)-oxytocin analogs. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2001; 58:263-73. [PMID: 11576333 DOI: 10.1034/j.1399-3011.2001.00932.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Six [Pen(6)]oxytocin analogs were synthesized by substituting penicillamine for cysteine in oxytocin, [Mpa(1)]oxytocin, [dPen(1)]oxytocin, [5-t-BuPro(7)]oxytocin, [Mpa(1), 5-t-BuPro(7)]oxytocin and [dPen(1), 5-t-BuPro(7)]oxytocin. When tested in the uterotonic test in vitro [Pen(6)]oxytocin, [Pen(6), 5-t-BuPro(7)]oxytocin, [Mpa(1), Pen(6)]oxytocin and [Mpa(1), Pen(6), 5-t-BuPro(7)]oxytocin, all were found to possess both agonistic and antagonistic properties. Their agonistic potency ranged from negligible (0.08 IU/mg) to low (5.85 IU/mg) and their antagonistic potency (pA2) was estimated to range from 6.6 to 7.9. [dPen(1), Pen(6)]Oxytocin and [dPen(1), Pen(6), 5-t-BuPro(7)]oxytocin were found to be pure antagonists with similarly high pA2 values of approximately 8.2. Replacement of proline by 5-tert-butylproline increased binding affinity by a factor of two in [Pen(6)]oxytocin and had no influence on the binding affinity of [Mpa(1), Pen(6)]oxytocin and [dPen(1), Pen(6)]oxytocin. Assignment of the proton signals for prolyl amide cis- and trans-isomers by NMR experiments in water indicated that the Pen(6)-5-tert-BuPro(7) peptide bond cis-isomer population was augmented relative to the prolyl peptides and measured, respectively, at 20, 35 and 35% in the 5-tert-butylproline(7) analogs of [Pen(6)]oxytocin, [Mpa(1), Pen(6)]oxytocin and [dPen(1), Pen(6)]oxytocin. This augmentation in cis-isomer population was correlated with a 21-fold reduction in the agonistic potency and 2-fold augmentation in antagonistic potency for [Pen(6), 5-t-BuPro(7)]oxytocin relative to [Pen(6)]oxytocin. Augmentation of cis-isomer population was also correlated to reduced agonist potency without effect on antagonism on conversion of [Mpa(1), Pen(6)]oxytocin to [Mpa(1), Pen(6), 5-t-BuPro(7)]oxytocin. In the potent oxytocin antagonist, [dPen(1), Pen(6)]oxytocin, substitution of 5-tert-butylproline for proline augmented the cis-isomer population without affecting antagonistic potency. The synthesis and evaluation of [Pen(6)]oxytocin and [Pen(6), 5-t-BuPro(7)]oxytocin analogs 1-6 indicated that steric interactions influenced agonist and antagonist activity by modifying peptide conformation. Augmentations in the prolyl cis-isomer population caused by 5-tert-butylproline occurred concurrently with enhanced or maintained antagonistic potency and binding affinity and reduced agonistic potency.
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Affiliation(s)
- L Bélec
- Département de chimie, Université de Montréal, Montréal, Québec, Canada
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22
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Carnazzi E, Aumelas A, Mouillac B, Breton C, Guillou L, Barberis C, Seyer R. Design, synthesis and pharmacological characterization of a potent radioiodinated and photoactivatable peptidic oxytocin antagonist. J Med Chem 2001; 44:3022-30. [PMID: 11520211 DOI: 10.1021/jm010125u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Using a segment strategy, we have synthesized four iodinated photoactivatable cyclic peptidic ligands of oxytocin, bearing a beta-mercapto-betabeta-cyclopentamethylene propionic group (Pmp) on their N-terminus. All the syntheses were RP-HPLC monitored, and the compounds were HPLC purified. They were characterized by 1H NMR, MALDI-TOF, or FAB mass spectrometries. The affinities of Pmp-Tyr(Me)-Ile-Thr-Asn-Cys-Gly-Orn-Phe(3I,4N3)-NH2 (20), Pmp-Tyr-Ile-Thr-Asn-Cys-Gly-Orn-Phe(3I,4N3)-NH2 (21), Pmp-Tyr(Me)-Ile-Thr-Asn-Cys-Pro-Orn-Phe(3I,4N3)-NH2 (22), and Pmp-Tyr-Ile-Thr-Asn-Cys-Pro-Orn-Phe(3I,4N3)-NH2 (23) were evaluated as inhibition constants (K(i), in nM) for the human oxytocin receptor expressed in Chinese hamster ovary cells by displacement of a radioiodinated disulfide-cyclized antagonist (Elands et al. Eur. J. Pharmacol. 1987, 147, 197-207). The most potent of them, compound 22, was synthesized by another method in order to allow its radiolabeling by 125I. Its dissociation constant (K(d)) for the human oxytocin receptor, directly measured in saturation studies, was 0.25 +/- 0.04 nM, and its antagonist properties were determined by inactivation of phospholipase C, thus obtaining an inactivation constant (K(inact)) of 0.18 +/- 0.02 nM, evaluated by inositol phosphate accumulation. This compound is a very good tool for the mapping of peptidic antagonist binding sites in the human oxytocin receptor.
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MESH Headings
- Animals
- Binding, Competitive
- CHO Cells
- Chromatography, High Pressure Liquid
- Cricetinae
- Drug Design
- Humans
- In Vitro Techniques
- Inositol Phosphates/biosynthesis
- Iodine Radioisotopes
- Magnetic Resonance Spectroscopy
- Peptides, Cyclic/chemical synthesis
- Peptides, Cyclic/chemistry
- Peptides, Cyclic/pharmacology
- Photolysis
- Radioligand Assay
- Receptors, Oxytocin/antagonists & inhibitors
- Spectrometry, Mass, Fast Atom Bombardment
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Structure-Activity Relationship
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Affiliation(s)
- E Carnazzi
- CNRS UPR 9023 and INSERM U 469, CCIPE, 141, rue de la Cardonille, 34094 Montpellier Cedex 5, France.
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23
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24
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Pyroglutamic acid as a pseudoproline moiety: a facile method for its introduction into polypeptide chains. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)00981-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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25
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26
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Halab L, Lubell WD. Influence of N-terminal residue stereochemistry on the prolyl amide geometry and the conformation of 5-tert-butylproline type VI beta-turn mimics. J Pept Sci 2001; 7:92-104. [PMID: 11277501 DOI: 10.1002/psc.297] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The effects of N-terminal amino acid stereochemistry on prolyl amide geometry and peptide turn conformation were investigated by coupling both L- and D-amino acids to (2S, 5R)-5-tert-butylproline and L-proline to generate, respectively, N-(acetyl)dipeptide N'-methylamides 1 and 2. Prolyl amide cis- and trans-isomers were, respectively, favored for peptides 1 and 2 as observed by proton NMR spectroscopy in water, DMSO and chloroform. The influence of solvent composition on amide proton chemical shift indicated an intramolecular hydrogen bond between the N'-methylamide proton and the acetamide carbonyl for the major conformer of dipeptides (S)-1, that became less favorable in (R)-1 and 2. The coupling constant (3J(NH,alpha)) values for the cis-isomer of (R)-1 indicated a phi2 dihedral angle value characteristic of a type VIb beta-turn conformation in solution. X-ray crystallographic analysis of N-acetyl-D-leucyl-5-tert-butylproline N'-methylamide (R)-lb showed the prolyl residue in a type VIb beta-turn geometry possessing an amide cis-isomer and psi3-dihedral angle having a value of 157 degrees, which precluded an intramolecular hydrogen bond. Intermolecular hydrogen bonding between the leucyl residues of two turn structures within the unit cell positioned the N-terminal residue in a geometry where their phi2 and psi2 dihedral angle values were not characteristic of an ideal type VIb turn. The circular dichroism spectra of tert-butylprolyl peptides (S)- and (R)-1b were found not to be influenced by changes in solvent composition from water to acetonitrile. The type B spectrum exhibited by (S)-1b has been previously assigned to a type VIa beta-turn conformation [Halab L, Lubell WD. J. Org. Chem. 1999; 64: 3312-3321]. The type C spectrum exhibited by the (R)-lb has previously been associated with type II' beta-turn and alpha-helical conformations in solution and appears now to be also characteristic for a type VIb geometry.
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Affiliation(s)
- L Halab
- Département de chimie, Université de Montréal, Québec, Canada
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27
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Demange L, Cluzeau J, Ménez A, Dugave C. Synthesis of optically pure N-Boc-protected (2R,3R)- and (2R,3S)-3-fluoroprolines. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(00)02030-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Wei L, Lubell WD. Racemization in the use of N-(9-(9-phenylfluorenyl))serine-derived cyclic sulfamidates in the synthesis of delta-keto alpha-amino carboxylates and prolines. Org Lett 2000; 2:2595-8. [PMID: 10990405 DOI: 10.1021/ol006102b] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text]Ring opening of enantiopure N-(9-(9-phenylfluorenyl)serine-derived cyclic sulfamidates with beta-keto esters, beta-keto ketones, and dimethyl malonate gave a variety of gamma-substituted amino acid analogues in racemic form. Investigation of the mechanism for racemization revealed that beta-elimination occurred to form a dehydroalanine intermediate that underwent subsequent Michael addition.
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Affiliation(s)
- L Wei
- Département de chimie, Université de Montréal, Québec, Canada
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