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Zhao W, Han S, Qiu N, Feng W, Lu M, Zhang W, Wang M, Zhou Q, Chen S, Xu W, Du J, Chu X, Yi C, Dai A, Hu L, Shen MY, Sun Y, Zhang Q, Ma Y, Zhong W, Yang D, Wang MW, Wu B, Zhao Q. Structural insights into ligand recognition and selectivity of somatostatin receptors. Cell Res 2022; 32:761-772. [PMID: 35739238 PMCID: PMC9343605 DOI: 10.1038/s41422-022-00679-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/25/2022] [Indexed: 12/12/2022] Open
Abstract
Somatostatin receptors (SSTRs) play versatile roles in inhibiting the secretion of multiple hormones such as growth hormone and thyroid-stimulating hormone, and thus are considered as targets for treating multiple tumors. Despite great progress made in therapeutic development against this diverse receptor family, drugs that target SSTRs still show limited efficacy with preferential binding affinity and conspicuous side-effects. Here, we report five structures of SSTR2 and SSTR4 in different states, including two crystal structures of SSTR2 in complex with a selective peptide antagonist and a non-peptide agonist, respectively, a cryo-electron microscopy (cryo-EM) structure of Gi1-bound SSTR2 in the presence of the endogenous ligand SST-14, as well as two cryo-EM structures of Gi1-bound SSTR4 in complex with SST-14 and a small-molecule agonist J-2156, respectively. By comparison of the SSTR structures in different states, molecular mechanisms of agonism and antagonism were illustrated. Together with computational and functional analyses, the key determinants responsible for ligand recognition and selectivity of different SSTR subtypes and multiform binding modes of peptide and non-peptide ligands were identified. Insights gained in this study will help uncover ligand selectivity of various SSTRs and accelerate the development of new molecules with better efficacy by targeting SSTRs.
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Affiliation(s)
- Wenli Zhao
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Shuo Han
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, Zhejiang, China
| | - Na Qiu
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wenbo Feng
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Mengjie Lu
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wenru Zhang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Mu Wang
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Qingtong Zhou
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Shutian Chen
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Wei Xu
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Juan Du
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, Zhejiang, China
| | - Xiaojing Chu
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Cuiying Yi
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Antao Dai
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | | | | | | | | | - Yingli Ma
- Amgen Asia R&D Center, Shanghai, China
| | - Wenge Zhong
- Amgen Asia R&D Center, Shanghai, China.,Regor Therapeutics, Shanghai, China
| | - Dehua Yang
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China. .,University of Chinese Academy of Sciences, Beijing, China. .,The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
| | - Ming-Wei Wang
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China. .,University of Chinese Academy of Sciences, Beijing, China. .,Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai, China. .,School of Life Science and Technology, ShanghaiTech University, Shanghai, China. .,The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
| | - Beili Wu
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China. .,University of Chinese Academy of Sciences, Beijing, China. .,School of Pharmaceutical Science and Technology, Hangzhou Institute for Advanced Study, UCAS, Hangzhou, Zhejiang, China. .,School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
| | - Qiang Zhao
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China. .,University of Chinese Academy of Sciences, Beijing, China. .,School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China. .,Zhongshan Institute of Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan, Guangdong, China.
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2
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Vu O, Bender BJ, Pankewitz L, Huster D, Beck-Sickinger AG, Meiler J. The Structural Basis of Peptide Binding at Class A G Protein-Coupled Receptors. Molecules 2021; 27:molecules27010210. [PMID: 35011444 PMCID: PMC8746363 DOI: 10.3390/molecules27010210] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 12/15/2021] [Accepted: 12/18/2021] [Indexed: 11/16/2022] Open
Abstract
G protein-coupled receptors (GPCRs) represent the largest membrane protein family and a significant target class for therapeutics. Receptors from GPCRs’ largest class, class A, influence virtually every aspect of human physiology. About 45% of the members of this family endogenously bind flexible peptides or peptides segments within larger protein ligands. While many of these peptides have been structurally characterized in their solution state, the few studies of peptides in their receptor-bound state suggest that these peptides interact with a shared set of residues and undergo significant conformational changes. For the purpose of understanding binding dynamics and the development of peptidomimetic drug compounds, further studies should investigate the peptide ligands that are complexed to their cognate receptor.
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Affiliation(s)
- Oanh Vu
- Deparment of Chemistry, Vanderbilt University, Nashville, TN 37235, USA;
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA; (B.J.B.); (L.P.)
| | - Brian Joseph Bender
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA; (B.J.B.); (L.P.)
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Lisa Pankewitz
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA; (B.J.B.); (L.P.)
| | - Daniel Huster
- Institute for Medical Physics and Biophysics, Medical Department, Leipzig University, Härtelstr. 16–18, D-04107 Leipzig, Germany;
| | - Annette G. Beck-Sickinger
- Faculty of Life Sciences, Institute of Biochemistry, Leipzig University, Brüderstr. 34, D-04103 Leipzig, Germany;
| | - Jens Meiler
- Deparment of Chemistry, Vanderbilt University, Nashville, TN 37235, USA;
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA; (B.J.B.); (L.P.)
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
- Leipzig University Medical Center, Institute for Drug Discovery, Departments of Chemistry and Computer Science, Leipzig University, Brüderstr. 34, D-04103 Leipzig, Germany
- Correspondence:
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3
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Structure-based design of a Cortistatin analogue with immunomodulatory activity in models of inflammatory bowel disease. Nat Commun 2021; 12:1869. [PMID: 33767180 PMCID: PMC7994712 DOI: 10.1038/s41467-021-22076-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/24/2021] [Indexed: 12/11/2022] Open
Abstract
Ulcerative colitis and Crohn’s disease are forms of inflammatory bowel disease whose incidence and prevalence are increasing worldwide. These diseases lead to chronic inflammation of the gastrointestinal tract as a result of an abnormal response of the immune system. Recent studies positioned Cortistatin, which shows low stability in plasma, as a candidate for IBD treatment. Here, using NMR structural information, we design five Cortistatin analogues adopting selected native Cortistatin conformations in solution. One of them, A5, preserves the anti-inflammatory and immunomodulatory activities of Cortistatin in vitro and in mouse models of the disease. Additionally, A5 displays an increased half-life in serum and a unique receptor binding profile, thereby overcoming the limitations of the native Cortistatin as a therapeutic agent. This study provides an efficient approach to the rational design of Cortistatin analogues and opens up new possibilities for the treatment of patients that fail to respond to other therapies. Inflammatory bowel disease is caused by chronic inflammation of the gastrointestinal tract and disturbed immune responses. Here the authors present examination of Cortistatin analogues that display enhanced half-life stability whilst maintaining immunomodulatory functionality.
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4
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Shenoy PA, Kuo A, Khan N, Gorham L, Nicholson JR, Corradini L, Vetter I, Smith MT. The Somatostatin Receptor-4 Agonist J-2156 Alleviates Mechanical Hypersensitivity in a Rat Model of Breast Cancer Induced Bone Pain. Front Pharmacol 2018; 9:495. [PMID: 29867498 PMCID: PMC5962878 DOI: 10.3389/fphar.2018.00495] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 04/25/2018] [Indexed: 12/12/2022] Open
Abstract
In the majority of patients with breast cancer in the advanced stages, skeletal metastases are common, which may cause excruciating pain. Currently available drug treatments for relief of breast cancer-induced bone pain (BCIBP) include non-steroidal anti-inflammatory drugs and strong opioid analgesics along with inhibitors of osteoclast activity such as bisphosphonates and monoclonal antibodies such as denosumab. However, these medications often lack efficacy and/or they may produce serious dose-limiting side effects. In the present study, we show that J-2156, a somatostatin receptor type 4 (SST4 receptor) selective agonist, reverses pain-like behaviors in a rat model of BCIBP induced by unilateral intra-tibial injection of Walker 256 breast cancer cells. Following intraperitoneal administration, the ED50 of J-2156 for the relief of mechanical allodynia and mechanical hyperalgesia in the ipsilateral hindpaws was 3.7 and 8.0 mg/kg, respectively. Importantly, the vast majority of somatosensory neurons in the dorsal root ganglia including small diameter C-fibers and medium-large diameter fibers, that play a crucial role in cancer pain hypersensitivities, expressed the SST4 receptor. J-2156 mediated pain relief in BCIBP-rats was confirmed by observations of a reduction in the levels of phosphorylated extracellular signal-regulated kinase (pERK), a protein essential for central sensitization and persistent pain, in the spinal dorsal horn. Our results demonstrate the potential of the SST4 receptor as a pharmacological target for relief of BCIBP and we anticipate the present work to be a starting point for further mechanism-based studies.
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Affiliation(s)
- Priyank A Shenoy
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Andy Kuo
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Nemat Khan
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Louise Gorham
- Department of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Janet R Nicholson
- Department of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Laura Corradini
- Department of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.,Faculty of Health and Behavioural Sciences, School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
| | - Maree T Smith
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia.,Faculty of Health and Behavioural Sciences, School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
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5
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Peptide aromatic interactions modulated by fluorinated residues: Synthesis, structure and biological activity of Somatostatin analogs containing 3-(3',5'difluorophenyl)-alanine. Sci Rep 2016; 6:27285. [PMID: 27271737 PMCID: PMC4895178 DOI: 10.1038/srep27285] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 05/17/2016] [Indexed: 12/18/2022] Open
Abstract
Somatostatin is a 14-residue peptide hormone that regulates the endocrine system by binding to five G-protein-coupled receptors (SSTR1–5). We have designed six new Somatostatin analogs with L-3-(3′,5′-difluorophenyl)-alanine (Dfp) as a substitute of Phe and studied the effect of an electron-poor aromatic ring in the network of aromatic interactions present in Somatostatin. Replacement of each of the Phe residues (positions 6, 7 and 11) by Dfp and use of a D-Trp8 yielded peptides whose main conformations could be characterized in aqueous solution by NMR. Receptor binding studies revealed that the analog with Dfp at position 7 displayed a remarkable affinity to SSTR2 and SSTR3. Analogs with Dfp at positions 6 or 11 displayed a π-π interaction with the Phe present at 11 or 6, respectively. Interestingly, these analogs, particularly [D-Trp8,L-Dfp11]-SRIF, showed high selectivity towards SSTR2, with a higher value than that of Octreotide and a similar one to that of native Somatostatin.
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6
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The production of recombinant 15N, 13C-labelled somatostatin 14 for NMR spectroscopy. Protein Expr Purif 2014; 99:78-86. [DOI: 10.1016/j.pep.2014.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 03/12/2014] [Accepted: 03/19/2014] [Indexed: 01/29/2023]
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7
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Martín-Gago P, Aragón E, Gomez-Caminals M, Fernández-Carneado J, Ramón R, Martin-Malpartida P, Verdaguer X, López-Ruiz P, Colás B, Cortes MA, Ponsati B, Macias MJ, Riera A. Insights into structure-activity relationships of somatostatin analogs containing mesitylalanine. Molecules 2013; 18:14564-84. [PMID: 24287991 PMCID: PMC6270305 DOI: 10.3390/molecules181214564] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 12/29/2022] Open
Abstract
The non-natural amino acid mesitylalanine (2,4,6-trimethyl-L-phenylalanine; Msa) has an electron-richer and a more conformationally restricted side-chain than that of its natural phenylalanine counterpart. Taking these properties into account, we have synthesized ten somatostatin analogs containing Msa residues in different key positions to modify the intrinsic conformational flexibility of the natural hormone. We have measured the binding affinity of these analogs and correlated it with the main conformations they populate in solution. NMR and computational analysis revealed that analogs containing one Msa residue were conformationally more restricted than somatostatin under similar experimental conditions. Furthermore, we were able to characterize the presence of a hairpin at the pharmacophore region and a non-covalent interaction between aromatic residues 6 and 11. In all cases, the inclusion of a D-Trp in the eighth position further stabilized the main conformation. Some of these peptides bound selectively to one or two somatostatin receptors with similar or even higher affinity than the natural hormone. However, we also found that multiple incorporations of Msa residues increased the life span of the peptides in serum but with a loss of conformational rigidity and binding affinity.
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Affiliation(s)
- Pablo Martín-Gago
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
| | - Eric Aragón
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
| | - Marc Gomez-Caminals
- BCN Peptides S.A. Pol.Ind. Els Vinyets-Els Fogars, Sector II. Ctra. Comarcal 244, Km. 22, 08777 Sant Quintí de Mediona, Barcelona 08777, Spain; E-Mails: (M.G.-C.); (J.F.-C.); (B.P.)
| | - Jimena Fernández-Carneado
- BCN Peptides S.A. Pol.Ind. Els Vinyets-Els Fogars, Sector II. Ctra. Comarcal 244, Km. 22, 08777 Sant Quintí de Mediona, Barcelona 08777, Spain; E-Mails: (M.G.-C.); (J.F.-C.); (B.P.)
| | - Rosario Ramón
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
- Departament de Química Orgànica, Universitat de Barcelona, Martí i Franqués, 1-11, Barcelona 08028, Spain
| | - Pau Martin-Malpartida
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
| | - Xavier Verdaguer
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
- Departament de Química Orgànica, Universitat de Barcelona, Martí i Franqués, 1-11, Barcelona 08028, Spain
| | - Pilar López-Ruiz
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Facultad de Medicina, Madrid 28871, Spain; E-Mails: (P.L.-R.); (B.C.); (M.A.C.)
| | - Begoña Colás
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Facultad de Medicina, Madrid 28871, Spain; E-Mails: (P.L.-R.); (B.C.); (M.A.C.)
| | - María Alicia Cortes
- Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá de Henares, Facultad de Medicina, Madrid 28871, Spain; E-Mails: (P.L.-R.); (B.C.); (M.A.C.)
| | - Berta Ponsati
- BCN Peptides S.A. Pol.Ind. Els Vinyets-Els Fogars, Sector II. Ctra. Comarcal 244, Km. 22, 08777 Sant Quintí de Mediona, Barcelona 08777, Spain; E-Mails: (M.G.-C.); (J.F.-C.); (B.P.)
| | - Maria J. Macias
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluis Companys, 23, Barcelona 08010, Spain
- Authors to whom correspondence should be addressed; E-Mails: (M.J.M.); (A.R.); Tel.: +34-934-037-189 (M.J.M.); Fax: +34-934-047-095 (M.J.M.); Tel. +34-934-047-093 (A.R.); Fax: +34-934-047-095 (A.R)
| | - Antoni Riera
- Institute for Research in Biomedicine (IRB Barcelona) Baldiri Reixac, 10, Barcelona 08028, Spain; E-Mails: (P.M.-G.); (E.A.); (R.R.); (P.M.-M.); (X.V.)
- Departament de Química Orgànica, Universitat de Barcelona, Martí i Franqués, 1-11, Barcelona 08028, Spain
- Authors to whom correspondence should be addressed; E-Mails: (M.J.M.); (A.R.); Tel.: +34-934-037-189 (M.J.M.); Fax: +34-934-047-095 (M.J.M.); Tel. +34-934-047-093 (A.R.); Fax: +34-934-047-095 (A.R)
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8
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Erchegyi J, Cescato R, Waser B, Rivier JE, Reubi JC. N-imidazolebenzyl-histidine substitution in somatostatin and in its octapeptide analogue modulates receptor selectivity and function. J Med Chem 2011; 54:5981-7. [PMID: 21806016 DOI: 10.1021/jm200307v] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Despite 3 decades of focused chemical, biological, structural, and clinical developments, unusual properties of somatostatin (SRIF, 1) analogues are still being uncovered. Here we report the unexpected functional properties of 1 and the octapeptide cyclo(3-14)H-Cys-Phe-Phe-Trp(8)-Lys-Thr-Phe-Cys-OH (somatostatin numbering; OLT-8, 9) substituted by imBzl-l- or -d-His at position 8. These analogues were tested for their binding affinity to the five human somatostatin receptors (sst(1-5)), as well as for their functional properties (or functionalities) in an sst(3) internalization assay and in an sst(3) luciferase reporter gene assay. While substitution of Trp(8) in somatostatin by imBzl-l- or -d-His(8) results in sst(3) selectivity, substitution of Trp(8) in the octapeptide 9 by imBzl-l- or -d-His(8) results in loss of binding affinity for sst(1,2,4,5) and a radical functional switch from agonist to antagonist.
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Affiliation(s)
- Judit Erchegyi
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, 10010 N. Torrey Pines Road, La Jolla, California 92037, USA
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9
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Di Cianni A, Carotenuto A, Brancaccio D, Novellino E, Reubi JC, Beetschen K, Papini AM, Ginanneschi M. Novel Octreotide Dicarba-analogues with High Affinity and Different Selectivity for Somatostatin Receptors. J Med Chem 2010; 53:6188-97. [DOI: 10.1021/jm1005868] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Alessandra Di Cianni
- Laboratory of Peptides & Proteins, Chemistry & Biology, University of Firenze, Via della Lastruccia 13, I-50019 Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Firenze, Via della Lastruccia 5-13, I-50019, Sesto Fiorentino, Italy
| | - Alfonso Carotenuto
- Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, I-80131 Napoli, Italy
| | - Diego Brancaccio
- Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, I-80131 Napoli, Italy
| | - Ettore Novellino
- Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, I-80131 Napoli, Italy
| | - Jean Claude Reubi
- Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31, CH-3010 Berne, Switzerland
| | - Karin Beetschen
- Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31, CH-3010 Berne, Switzerland
| | - Anna Maria Papini
- Laboratory of Peptides & Proteins, Chemistry & Biology, University of Firenze, Via della Lastruccia 13, I-50019 Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Firenze, Via della Lastruccia 5-13, I-50019, Sesto Fiorentino, Italy
| | - Mauro Ginanneschi
- Laboratory of Peptides & Proteins, Chemistry & Biology, University of Firenze, Via della Lastruccia 13, I-50019 Sesto Fiorentino, Italy
- Department of Chemistry “Ugo Schiff”, University of Firenze, Via della Lastruccia 5-13, I-50019, Sesto Fiorentino, Italy
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10
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Ovadia O, Greenberg S, Laufer B, Gilon C, Hoffman A, Kessler H. Improvement of drug-like properties of peptides: the somatostatin paradigm. Expert Opin Drug Discov 2010; 5:655-71. [DOI: 10.1517/17460441.2010.493935] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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11
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Beierle J, Horne W, van Maarseveen J, Waser B, Reubi J, Ghadiri M. Conformationally Homogeneous Heterocyclic Pseudotetrapeptides as Three‐Dimensional Scaffolds for Rational Drug Design: Receptor‐Selective Somatostatin Analogues. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200805901] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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12
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Erchegyi J, Cescato R, Grace CRR, Waser B, Piccand V, Hoyer D, Riek R, Rivier JE, Reubi JC. Novel, potent, and radio-iodinatable somatostatin receptor 1 (sst1) selective analogues. J Med Chem 2009; 52:2733-46. [PMID: 19351180 DOI: 10.1021/jm801314f] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The proposed sst(1) pharmacophore (J. Med. Chem. 2005, 48, 523-533) derived from the NMR structures of a family of mono- and dicyclic undecamers was used to design octa-, hepta-, and hexamers with high affinity and selectivity for the somatostatin sst(1) receptor. These compounds were tested for their in vitro binding properties to all five somatostatin (SRIF) receptors using receptor autoradiography; those with high SRIF receptor subtype 1 (sst(1)) affinity and selectivity were shown to be agonists when tested functionally in a luciferase reporter gene assay. Des-AA(1,4-6,10,12,13)-[DTyr(2),DAgl(NMe,2naphthoyl)(8),IAmp(9)]-SRIF-Thr-NH(2) (25) was radio-iodinated ((125)I-25) and specifically labeled sst(1)-expressing cells and tissues. 3D NMR structures were calculated for des-AA(1,4-6,10,12,13)-[DPhe(2),DTrp(8),IAmp(9)]-SRIF-Thr-NH(2) (16), des-AA(1,2,4-6,10,12,13)-[DAgl(NMe,2naphthoyl)(8),IAmp(9)]-SRIF-Thr-NH(2) (23), and des-AA(1,2,4-6,10,12,13)-[DAgl(NMe,2naphthoyl)(8),IAmp(9),Tyr(11)]-SRIF-NH(2) (27) in DMSO. Though the analogues have the sst(1) pharmacophore residues at the previously determined distances from each other, the positioning of the aromatic residues in 16, 23, and 27 is different from that described earlier, suggesting an induced fit mechanism for sst(1) binding of these novel, less constrained sst(1)-selective family members.
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Affiliation(s)
- Judit Erchegyi
- The Clayton Foundation Laboratories for Peptide Biology, La Jolla, California 92037, USA
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13
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Beierle JM, Horne WS, van Maarseveen JH, Waser B, Reubi JC, Reza Ghadiri M. Conformationally homogeneous heterocyclic pseudotetrapeptides as three-dimensional scaffolds for rational drug design: receptor-selective somatostatin analogues. Angew Chem Int Ed Engl 2009; 48:4725-9. [PMID: 19266506 PMCID: PMC3080139 DOI: 10.1002/anie.200805901] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A would-be amide: A 1,4-disubstituted 1,2,3-triazole was used as a surrogate for a trans amide bond to create a library of 16 diastereomeric pseudotetrapeptides as beta-turn mimetics. High-resolution structural analysis indicated that these scaffolds adopt distinct, rigid, conformationally homogeneous beta-turn-like structures (see example), some of which bind somatostatin receptor subtypes selectively, and some of which show broad-spectrum activity.
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Affiliation(s)
- John M. Beierle
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - W. Seth Horne
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Jan H. van Maarseveen
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
| | - Beatrice Waser
- Division of Cell Biology and Experimental Cancer Research University of Berne Berne, Switzerland 3010
| | - Jean Claude Reubi
- Division of Cell Biology and Experimental Cancer Research University of Berne Berne, Switzerland 3010
| | - M. Reza Ghadiri
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037 (USA)
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14
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Grace CRR, Erchegyi J, Reubi JC, Rivier JE, Riek R. Three-dimensional consensus structure of sst2-selective somatostatin (SRIF) antagonists by NMR. Biopolymers 2008; 89:1077-87. [PMID: 18655144 DOI: 10.1002/bip.21060] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The three-dimensional NMR structures of seven octapeptide analogs of somatostatin (SRIF), based on octreotide, with the basic sequence H-Cpa/Phe2-c[DCys3-Xxx7-DTrp/DAph(Cbm)8-Lys9-Thr10-Cys14]-Yyy-NH2 (the numbering refers to the position in native SRIF), with Xxx7 being Aph(Cbm)/Tyr/Agl(NMe,benzoyl) and Yyy being Nal/DTyr/Thr, are presented here. Most of these analogs exhibit potent and highly selective binding to sst2 receptors, and all of the analogs are antagonists inhibiting receptor signaling. Based on their consensus 3D structure, the pharmacophore of the sst2-selective antagonist has been defined. The pharmacophore involves the side chains of Cpa2, DTrp/DAph(Cbm)8, and Lys9, with the backbone for most of the sst2-selective antagonists comprised a Type-II' beta-turn. Hence, the sst2-selective antagonist pharmacophore is very similar to the sst2-selective agonist pharmacophore previously described.
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Affiliation(s)
- Christy Rani R Grace
- Structural Biology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
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15
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Feytens D, De Vlaeminck M, Cescato R, Tourwé D, Reubi JC. Highly Potent 4-Amino-indolo[2,3-c]azepin-3-one-Containing Somatostatin Mimetics with a Range of sst Receptor Selectivities. J Med Chem 2008; 52:95-104. [DOI: 10.1021/jm801205x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Debby Feytens
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Berne, Switzerland
| | - Magali De Vlaeminck
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Berne, Switzerland
| | - Renzo Cescato
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Berne, Switzerland
| | - Dirk Tourwé
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Berne, Switzerland
| | - Jean Claude Reubi
- Department of Organic Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Berne, Switzerland
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16
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Moore SB, Grant M, Rew Y, Bosa E, Fabbri M, Kumar U, Goodman M. Synthesis and biologic activity of conformationally constrained analogs of L-363,301. ACTA ACUST UNITED AC 2008; 66:404-22. [PMID: 16316457 DOI: 10.1111/j.1399-3011.2005.00309.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the synthesis, biological activity and conformational analysis of analogs of the cyclic hexapeptide L-363,301, c[Pro6-Phe7-D-Trp8-Lys9-Thr10-Phe11] (numbering as in the native hormone somatostatin-14). The d-Trp in position 8 was replaced with (2R,3S)- and (2R,3R)-beta-MeTrp respectively, with an added methyl group in the beta position of Trp. The objective of our study was to determine the potency and selectivity generated by the added constraint in the beta position of the d-Trp upon binding to human somatostatin receptors hsst1-5. We synthesized the building blocks enantioselectively and incorporated them into the peptides by SPPS. Competition binding assays revealed that both compounds 2 and 3 were selective for hsst2 over hsst5. The (2R,3S) analog 2 was approximately 30 times more potent at hsst2 than the (2R,3R) analog 3. Interestingly, the (2R,3R) compound showed no binding affinity at hsst5.
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Affiliation(s)
- S B Moore
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0343, USA.
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17
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Seebach D, Dubost E, Mathad R, Jaun B, Limbach M, Löweneck M, Flögel O, Gardiner J, Capone S, Beck A, Widmer H, Langenegger D, Monna D, Hoyer D. New Open-Chain and Cyclic Tetrapeptides, Consisting ofα-,β2-, andβ3-Amino-Acid Residues, as Somatostatin Mimics - A Survey. Helv Chim Acta 2008. [DOI: 10.1002/hlca.200890190] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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18
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Erchegyi J, Grace CRR, Samant M, Cescato R, Piccand V, Riek R, Reubi JC, Rivier JE. Ring size of somatostatin analogues (ODT-8) modulates receptor selectivity and binding affinity. J Med Chem 2008; 51:2668-75. [PMID: 18410084 PMCID: PMC2782568 DOI: 10.1021/jm701444y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The synthesis, biological testing, and NMR studies of several analogues of H-c[Cys (3)-Phe (6)-Phe (7)-DTrp (8)-Lys (9)-Thr (10)-Phe (11)-Cys (14)]-OH (ODT-8, a pan-somatostatin analogue, 1) have been performed to assess the effect of changing the stereochemistry and the number of atoms in the disulfide bridge on binding affinity. Cysteine at positions 3 and/or 14 (somatostatin numbering) were/was substituted with d-cysteine, norcysteine, D-norcysteine, homocysteine, and/or D-homocysteine. The 3D structure analysis of selected partially selective, bioactive analogues (3, 18, 19, and 21) was carried out in dimethylsulfoxide. Interestingly and not unexpectedly, the 3D structures of these analogues comprised the pharmacophore for which the analogues had the highest binding affinities (i.e., sst 4 in all cases).
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Affiliation(s)
- Judit Erchegyi
- The Clayton Foundation Laboratories for Peptide Biology and Structural Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, California 92037, USA
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19
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D’Addona D, Carotenuto A, Novellino E, Piccand V, Reubi JC, Di Cianni A, Gori F, Papini AM, Ginanneschi M. Novel sst5-Selective Somatostatin Dicarba-Analogues: Synthesis and Conformation−Affinity Relationships. J Med Chem 2008; 51:512-20. [DOI: 10.1021/jm070886i] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Debora D’Addona
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
| | - Alfonso Carotenuto
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
| | - Ettore Novellino
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
| | - Véronique Piccand
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
| | - Jean Claude Reubi
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
| | - Alessandra Di Cianni
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
| | - Francesca Gori
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
| | - Anna Maria Papini
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
| | - Mauro Ginanneschi
- Laboratory of Peptides and Proteins, Chemistry and Biology, Department of Organic Chemistry, University of Firenze, Via Lastruccia 13 I-50019, Sesto Fiorentino, Italy, Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano 49, Italy, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Murtenstrasse 31 CH-3010 Berne, Switzerland, and Laboratory of Peptides and Proteins, Chemistry and Biology, Department of
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20
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Grace CRR, Cervini L, Gulyas J, Rivier J, Riek R. Astressin-amide and astressin-acid are structurally different in dimethylsulfoxide. Biopolymers 2007; 87:196-205. [PMID: 17657708 DOI: 10.1002/bip.20818] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The C-terminally amidated CRF antagonist astressin binds to CRF-R1 or CRF-R2 receptors with low nanomolar affinity while the corresponding astressin-acid has >100 times less affinity. To understand the role of the amide group in binding, the conformations of astressin-amide and astressin-acid were studied in DMSO using NMR techniques. The 3D NMR structures show that the backbones of both analogs prefer an alpha-helical conformation, with a small kink around Gln(26). However, astressin-amide has a well-defined helical structure from Leu(27) to Ile(41) and a conformation very similar to the bioactive conformation reported by our group (Grace et al., Proc Natl Acad Sci USA 2007, 104, 4858-4863). In contrast, astressin-acid has an irregular helical conformation from Arg(35) onward, including a rearrangement of the side chains in that region. This structural difference highlights the crucial role of the C-terminal amidation for stabilization of astressin's bioactive conformation.
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Affiliation(s)
- Christy Rani R Grace
- Structural Biology Laboratory, The Salk Institute for Biological Studies, LA Jolla, CA 92037, USA
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21
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Nikiforovich GV, Marshall GR, Achilefu S. Molecular modeling suggests conformational scaffolds specifically targeting five subtypes of somatostatin receptors. Chem Biol Drug Des 2007; 69:163-9. [PMID: 17441902 DOI: 10.1111/j.1747-0285.2007.00493.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Several analogs of somatostatin with conformational constraints in their peptide backbones have been modeled to determine energetically feasible conformations. Comparison of low-energy backbone structures of these peptides suggested unique conformations of the central Phe/Ala(i)-D-Trp(i+1)-Lys(i+2)-Thr(i+3) fragment characteristic for specific interactions of somatostatin with each of the five distinct subtypes of somatostatin receptors (SSTRs). The conformations obtained were in good agreement with experimental data obtained earlier by NMR measurements and/or X-ray crystallography. The results help rationalize experimental observations on the specificity of binding of various somatostatin analogs with different subtypes of the SSTRs. They also serve as templates for the design of conformationally constrained non-peptide scaffolds that effectively and selectively interact with different subtypes of SSTRs. Such scaffolds can be convenient carriers of radiolabels and near-infrared labels in specific agents for imaging tumors expressing different SSTR subtypes.
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Affiliation(s)
- Gregory V Nikiforovich
- Department of Biochemistry and Molecular Biology, Washington University Medical School, St. Louis, MO 63110, USA.
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Grace CRR, Erchegyi J, Koerber SC, Reubi JC, Rivier J, Riek R. Novel sst2-selective somatostatin agonists. Three-dimensional consensus structure by NMR. J Med Chem 2006; 49:4487-96. [PMID: 16854054 PMCID: PMC2515173 DOI: 10.1021/jm060363v] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The 3D NMR structures of six octapeptide agonist analogues of somatostatin (SRIF) in the free form are described. These analogues, with the basic sequence H-DPhe/Phe2-c[Cys3-Xxx7-DTrp8-Lys9-Thr10-Cys14]-Thr-NH2 (the numbering refers to the position in native SRIF), with Xxx7 being Ala/Aph, exhibit potent and highly selective binding to human SRIF type 2 (sst2) receptors. The backbone of these sst2-selective analogues have the usual type-II' beta-turn reported in the literature for sst2/3/5-subtype-selective analogues. Correlating the biological results and NMR studies led to the identification of the side chains of DPhe2, DTrp8, and Lys9 as the necessary components of the sst2 pharmacophore. This is the first study to show that the aromatic ring at position 7 (Phe7) is not critical for sst2 binding and that it plays an important role in sst3 and sst5 binding. This pharmacophore is, therefore, different from that proposed by others for sst2/3/5 analogues.
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Affiliation(s)
- Christy Rani R. Grace
- Structural Biology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Judit Erchegyi
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Steven C. Koerber
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jean Claude Reubi
- Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, Berne, Switzerland
| | - Jean Rivier
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
- Corresponding author: Jean Rivier The Salk Institute The Clayton Foundation Laboratories for Peptide Biology 10010 N. Torrey Pines Road La Jolla, CA 92037 (858) 453−4100 Fax: (858) 552−1546
| | - Roland Riek
- Structural Biology Laboratory, The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
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Gairí M, Saiz P, Madurga S, Roig X, Erchegyi J, Koerber SC, Reubi JC, Rivier JE, Giralt E. Conformational analysis of a potent SSTR3-selective somatostatin analogue by NMR in water solution. J Pept Sci 2006; 12:82-91. [PMID: 16365912 DOI: 10.1002/psc.743] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The three-dimensional structure of a potent SSTR3-selective analogue of somatostatin, cyclo(3-14)H-Cys(3)-Phe(6)-Tyr(7)-D-Agl(8)(N(beta) Me, 2-naphthoyl)-Lys(9)-Thr(10)-Phe(11)-Cys(14)-OH (des-AA(1, 2, 4, 5, 12, 13)[Tyr(7), D-Agl(8)(N(beta) Me, 2-naphthoyl)]-SRIF) (peptide 1) has been determined by (1)H NMR in water and molecular dynamics (MD) simulations. The peptide exists in two conformational isomers differing mainly by the cis/trans isomerization of the side chain in residue 8. The structure of 1 is compared with the consensus structural motifs of other somatostatin analogues that bind predominantly to SSTR1, SSTR2/SSTR5 and SSTR4 receptors, and to the 3D structure of a non-selective SRIF analogue, cyclo(3-14)H-Cys(3)-Phe(6)-Tyr(7)-D-2Nal(8)-Lys(9)-Thr(10)-Phe(11)-Cys(14)-OH (des-AA(1, 2, 4, 5, 12, 13)[Tyr(7), D-2Nal(8)]-SRIF) (peptide 2). The structural determinant factors that could explain selectivity of peptide 1 for SSTR3 receptors are discussed.
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Affiliation(s)
- Margarida Gairí
- NMR Facility, Serveis Cientificotècnics, University of Barcelona, Barcelona Science Park, Josep Samitier 1-5, 08028 Barcelona, Spain
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Rivier J, Erchegyi J, Hoeger C, Miller C, Low W, Wenger S, Waser B, Schaer JC, Reubi JC. Novel sst(4)-selective somatostatin (SRIF) agonists. 1. Lead identification using a betide scan. J Med Chem 2004; 46:5579-86. [PMID: 14667212 DOI: 10.1021/jm030243c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Hypothesizing that structural constraints in somatostatin (SRIF) analogues may result in receptor selectivity, and aiming to characterize the bioactive conformation of somatostatin at each of its five receptors, we carried out an N(beta)-methylated aminoglycine (Agl) scan of the octapeptide H-c[Cys(3)-Phe(6)-Phe(7)-dTrp(8)-Lys(9)-Thr(10)-Phe(11)-Cys(14)]-OH (SRIF numbering) (ODT-8) that is potent at all SRIF receptor subtypes (sst's) but sst(1). We found that H-c[Cys-LAgl(N(beta)Me,benzoyl)-Phe-DTrp-Lys-Thr-Phe-Cys]-OH (4), H-c[Cys-Phe-LAgl(N(beta)Me,benzoyl)-Trp-Lys-Thr-Phe-Cys]-OH (6), H-c[Cys-Phe-LAgl(N(beta)Me,benzoyl)-dTrp-Lys-Thr-Phe-Cys]-OH (8), and H-c[DCys-Phe-LAgl(N(beta)Me,benzoyl)-DTrp-Lys-Thr-Phe-Cys]-OH (10) had high affinity (IC(50) = 14.3, 5.4, 5.2, and 3.4 nM, respectively) and selectivity for sst(4) (>50-fold over the other receptors). The l-configuration at positions 7 and 8 (l(7), l(8)) yields greater sst(4) selectivity than the l(7), d(8) configuration (6 versus 8). Peptides with the d(7), l(8) (7) and d(7), d(8) (9) configurations are significantly less potent at all receptors. H-c[Cys-Phe-Phe-DTrp-LAgl(betaAla)-Thr-Phe-Cys]-OH (16), H-c[Cys-Phe-Phe-DTrp-DAgl(betaAla)-Thr-Phe-Cys]-OH (17), and their N(beta)Me derivatives at position 9 (18, 19) were essentially inactive. Potent but less sst(4)-selective were members of the Agl-scan at positions 10, H-c[Cys-Phe-Phe-dTrp-Lys-lAgl(N(beta)Me,HO-Ac)-Phe-Cys]-OH (20, IC(50) = 6.5 nM), and 11, H-c[Cys-Phe-Phe-DTrp-Lys-Thr-LAgl(N(beta)Me,benzoyl)-Cys]-OH (22, IC(50) = 6.9 nM), while the d-configuration at positions 10 (21) and 11 (23) led to reduced affinity. One of our best analogues, 8, is an agonist when tested for its ability to inhibit forskolin-stimulated cAMP accumulation in sst(4)-transfected CCL39 cells (EC(50) = 1.01 nM). All Agl-containing analogues were first synthesized using unresolved Fmoc-Agl(N(beta)Me,Boc)-OH, and the diastereomers were separated using HPLC. Chiral assignment at the Agl-containing residue was subsequently done using enzymatic degradation and by de novo synthesis in the cases of H-c[Cys-Phe-DAgl(N(beta)Me,benzoyl)-DTrp-Lys-Thr-Phe-Cys]-OH (9) and H-c[DCys-Phe-DAgl(N(beta)Me,benzoyl)-DTrp-Lys-Thr-Phe-Cys]-OH (11), starting with the papain-resolved Fmoc-DAgl(Boc). These results suggested that the orientation of side chains at position 6, 7, or 11 with respect to the side chains of residues 8 and 9 may be independently responsible for sst(4) selectivity.
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Affiliation(s)
- Jean Rivier
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Erchegyi J, Waser B, Schaer JC, Cescato R, Brazeau JF, Rivier J, Reubi JC. Novel sst(4)-selective somatostatin (SRIF) agonists. 3. Analogues amenable to radiolabeling. J Med Chem 2004; 46:5597-605. [PMID: 14667214 DOI: 10.1021/jm030245x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
After our discovery that H-c[Cys-Phe-Phe-DNal-Lys-Thr-Phe-Cys]-OH (ODN-8) had high affinity and marginal selectivity for human sst(3) (part 2 of this series: Erchegyi et al. J. Med. Chem., preceding paper in this issue)(11) and that H-c[Cys-Phe-Phe-DTrp-Lys-Thr-Phe-Cys]-OH (ODT-8, 3) had high affinity and marginal selectivity for human sst(4), that H-c[Cys-Phe-Tyr-D-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH had high affinity for all sst's except for sst(1), and that H-c[Cys-Phe-Tyr-L-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH had high affinity for sst(4) (IC(50) = 2.1 nM), with more than 50-fold selectivity toward the other receptors (parts 1 and 2 of this series: Rivier et al. and Erchegyi et al. J. Med. Chem., preceding papers in this issue), we found H-c[Cys-Phe-Phe-Trp-Lys-Thr-Phe-Cys]-OH (OLT-8, 2), H-c[Cys-Phe-Phe-L-threo-beta-MeTrp-Lys-Thr-Phe-Cys]-OH (4) and H-c[Cys-Phe-Phe-D-threo-beta-MeTrp-Lys-Thr-Phe-Cys]-OH (5) to have very high affinity for sst(4) (IC(50) = 0.7, 1.8, and 4.0 nM, respectively) and 5- to 10-fold selectivity versus the other sst's. From earlier work, we concluded that an l-amino acid at position 8 and a tyrosine or 4-aminophenylalanine substitution at position 7 may lead to high sst(4) selectivity. In fact, [Tyr(7)]-2 (6) and [Tyr(7)]-3 (7) show ca. 5-fold selectivity for sst(4), and [Aph(7)]-2 (8) and [Aph(7)]-3 (9) have high sst(4) affinity (IC(50) = 1.2 and 0.88 nM, respectively) and selectivity, suggesting that indeed an l-residue at position 8 will direct selectivity toward sst(4). Unexpectedly, [Ala(7)]-2 (10) and [Ala(7)]-3 (11) have very high sst(4) affinity (IC(50) = 0.84 and 0.98 nM, respectively) and selectivity (>600- and 200-fold, respectively). The combination of Tyr(2) and dTrp(8) in analogues 14 and 22 did not affect the affinity of the analogues for sst(4) (IC(50) = 1.2 and 1.1 nM, respectively) but resulted in loss of selectivity, whereas the combination of Tyr(2) and LTrp(8) in H-Tyr-c[Cys-Phe-Aph-Trp-Lys-Thr-Phe-Cys]-OH (13) and H-Tyr-c[Cys-Phe-Ala-Trp-Lys-Thr-Phe-Cys]-OH(19) retained high affinity (IC(50) = 1.9 and 1.98 nM, respectively) and sst(4) selectivity (>50 and >250, respectively). Interestingly, the same substitutions at positions 2 and 7, with l-threo-beta-MeTrp at position 8, yielded a much less selective analogue (20). Carbamoylation of the N-terminus of most of these analogues resulted in slightly improved affinity, selectivity, or both. Other amino acid substitutions in this series, such as those with Amp (25, 26), Orn (27), or IAmp (29) at position 7, were also tolerated but with a 2- to 3-fold loss of affinity and concomitant loss of selectivity. Analogous peptides with a tyrosine at position 11 (31-36) were less selective than the corresponding peptides with a tyrosine at position 2. Several analogues in this series compared favorably with the non-peptide L-803,087 (37) in terms of affinity and selectivity. Analogues 8, 10, and 21 potently inhibited the forskolin-stimulated cAMP production in sst(4)-transfected cells, therefore acting as full agonists. Cold monoiodination of 19 yielded 21, with retention of high sst(4) selectivity and affinity (IC(50) = 3.5 nM). (125)Iodinated 19 selectively binds to sst(4)-transfected cells but not to sst(1-3)- or sst(5)-transfected cells. Binding in sst(4)-transfected cells was completely displaced by SRIF-28 or the sst(4)-selective L-803,087.
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Affiliation(s)
- Judit Erchegyi
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
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Erchegyi J, Penke B, Simon L, Michaelson S, Wenger S, Waser B, Cescato R, Schaer JC, Reubi JC, Rivier J. Novel sst(4)-selective somatostatin (SRIF) agonists. 2. Analogues with beta-methyl-3-(2-naphthyl)alanine substitutions at position 8. J Med Chem 2004; 46:5587-96. [PMID: 14667213 DOI: 10.1021/jm0302445] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We present a family of human sst(4)-selective, high-affinity (IC(50) = 2-4 nM) cyclic somatostatin (SRIF) octapeptides. These peptides result from the substitution of dTrp(8) in H-c[Cys(3)-Phe(6)-Phe(7)-DTrp(8)-Lys(9)-Thr(10)-Phe(11)-Cys(14)]-OH (SRIF numbering) (ODT-8) by one of the four conformationally biased stereoisomers of beta-methyl-3-(2-naphthyl)alanine (beta-Me2Nal). Whereas H-c[Cys-Phe-Phe-DNal-Lys-Thr-Phe-Cys]-OH (ODN-8, 2) has high affinity and marginal selectivity for human sst(3) (Reubi et al., Proc. Natl. Acad. Sci. U.S.A. 2000, 97, 13973-13978), H-c[Cys-Phe-Tyr-D-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH (5) has high affinity for all sst's except for sst(1); H-c[Cys-Phe-Tyr-L-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH (6) has high affinity for sst(4) (IC(50) = 2.1 nM), with more than 50-fold selectivity toward the other receptors. Analogues 7 and 8, containing d- and l-erythro-beta-Me2Nal instead of the corresponding threo derivatives at position 8, are essentially inactive at all receptors. Substitution of Tyr(7) in 5 and 6 by Aph(7) resulted in 9 and 10 with similar affinity patterns overall yet lowered affinity. The substitution of DCys(3) for Cys(3) in 5 and 6 yielded H-c[DCys-Phe-Tyr-D-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH (11) and H-c[DCys-Phe-Tyr-L-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH (12), with biological profiles almost identical to those of their parents 5 and 6 (i.e., high affinity for sst(2-5) for 11 and high affinity and selectivity for sst(4) for 12). Analogue 12, with high sst(4) affinity combined with the highest sst(4) selectivity among all tested compounds, is an agonist in the cAMP accumulation assay (EC(50) = 1.29 nM). Cold monoiodination of 12 yielded 14, with loss of sst(4) selectivity and loss of high affinity (IC(50) = 21 nM). Introduction of Tyr(2) in 9 and 10 and substitution of Cys(3) by dCys(3), to yield 15 and 16 (IC(50) = 9.8 and 61 nM, respectively, for sst(4) and limited selectivity), failed to generate a high-affinity (125)iodinatable sst(4)-selective ligand. Substitution of Phe by Tyr at position 11 in H-c[DCys-Phe-Phe-L-threo-beta-Me2Nal-Lys-Thr-Phe-Cys]-OH yielded 18 (IC(50) = 11.8 nM at sst(4)), with limited sst(4) selectivity (30-fold or greater at the other receptors) yet only slightly improved affinity over that of 14. Cold monoiodination of 18 yielded 20 (IC(50) = 30 nM at sst(4) and high selectivity). Whereas we were able, in this study, to identify a new family of sst(4)-selective, high-affinity compounds, our additional goal, to identify highly potent and sst(4)-selective ligands amenable to (125)iodination, could not be achieved satisfactorily. On the other hand, some of the diastereomers identified in this study, such as 5, 11, 17, and 19, are very potent ligands at all receptors but sst(1).
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Affiliation(s)
- Judit Erchegyi
- The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
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