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Fetse J, Zhao Z, Liu H, Mamani UF, Mustafa B, Adhikary P, Ibrahim M, Liu Y, Patel P, Nakhjiri M, Alahmari M, Li G, Cheng K. Discovery of Cyclic Peptide Inhibitors Targeting PD-L1 for Cancer Immunotherapy. J Med Chem 2022; 65:12002-12013. [PMID: 36067356 PMCID: PMC10671706 DOI: 10.1021/acs.jmedchem.2c00539] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Blockade of the interaction between programmed cell death ligand-1 (PD-L1) and its receptor PD-1 has shown great success in cancer immunotherapy. Peptides possess unique characteristics that give them significant advantages as immune checkpoint inhibitors. However, unfavorable physicochemical properties and proteolytic stability profiles limit the translation of bioactive peptides as therapeutic agents. Studies have revealed that cyclization improves the biological activity and stability of linear peptides. In this study, we report the use of macrocyclization scanning for the discovery of cyclic anti-PD-L1 peptides with improved bioactivity. The cyclic peptides demonstrated up to a 34-fold improvement in the PD-1/PD-L1 blocking activity and significant in vivo anti-tumor activity. Our results demonstrate that macrocyclization scanning is an effective way to improve the serum stability and bioactivity of the anti-PD-L1 linear peptide. This strategy can be employed in the optimization of other bioactive peptides, particularly those for protein-protein interaction modulation.
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Affiliation(s)
- John Fetse
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Zhen Zhao
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Hao Liu
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Umar-Farouk Mamani
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Bahaa Mustafa
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Pratik Adhikary
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Mohammed Ibrahim
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Yanli Liu
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Pratikkumar Patel
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Maryam Nakhjiri
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Mohammed Alahmari
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
| | - Guangfu Li
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, One Hospital Drive, Columbia, MO 65212, USA
| | - Kun Cheng
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108, USA
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Sanner MF, Zoghebi K, Hanna S, Mozaffari S, Rahighi S, Tiwari RK, Parang K. Cyclic Peptides as Protein Kinase Inhibitors: Structure-Activity Relationship and Molecular Modeling. J Chem Inf Model 2021; 61:3015-3026. [PMID: 34000187 DOI: 10.1021/acs.jcim.1c00320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Under-expression or overexpression of protein kinases has been shown to be associated with unregulated cell signal transduction in cancer cells. Therefore, there is major interest in designing protein kinase inhibitors as anticancer agents. We have previously reported [WR]5, a peptide containing alternative arginine (R) and tryptophan (W) residues as a non-competitive c-Src tyrosine kinase inhibitor. A number of larger cyclic peptides containing alternative hydrophobic and positively charged residues [WR]x (x = 6-9) and hybrid cyclic-linear peptides, [R6K]W6 and [R5K]W7, containing R and W residues were evaluated for their protein kinase inhibitory potency. Among all the peptides, cyclic peptide [WR]9 was found to be the most potent tyrosine kinase inhibitor. [WR]9 showed higher inhibitory activity (IC50 = 0.21 μM) than [WR]5, [WR]6, [WR]7, and [WR]8 with IC50 values of 0.81, 0.57, 0.35, and 0.33 μM, respectively, against c-Src kinase as determined by a radioactive assay using [γ-33P]ATP. Consistent with the result above, [WR]9 inhibited other protein kinases such as Abl kinase activity with an IC50 value of 0.35 μM, showing 2.2-fold higher inhibition than [WR]5 (IC50 = 0.79 μM). [WR]9 also inhibited PKCa kinase activity with an IC50 value of 2.86 μM, approximately threefold higher inhibition than [WR]5 (IC50 = 8.52 μM). A similar pattern was observed against Braf, c-Src, Cdk2/cyclin A1, and Lck. [WR]9 exhibited IC50 values of <0.25 μM against Akt1, Alk, and Btk. These data suggest that [WR]9 is consistently more potent than other cyclic peptides with a smaller ring size and hybrid cyclic-linear peptides [R6K]W6 and [R5K]W7 against selected protein kinases. Thus, the presence of R and W residues in the ring, ring size, and the number of amino acids in the structure of the cyclic peptide were found to be critical in protein kinase inhibitory potency. We identified three putative binding pockets through automated blind docking of cyclic peptides [WR](5-9). The most populated pocket is located between the SH2, SH3, and N-lobe domains on the opposite side of the ATP binding site. The second putative pocket is formed by the same domains and located on the ATP binding site side of the protein. Finally, a third pocket was identified between the SH2 and SH3 domains. These results are consistent with the non-competitive nature of the inhibition displayed by these molecules. Molecular dynamics simulations of the protein-peptide complexes indicate that the presence of either [WR]5 or [WR]9 affects the plasticity of the protein and in particular the volume of the ATP binding site pocket in different ways. These results suggest that the second pocket is most likely the site where these peptides bind and offer a plausible rationale for the increased affinity of [WR]9.
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Affiliation(s)
- Michel F Sanner
- The Scripps Research Institute, La Jolla, California 92037, United States
| | - Khalid Zoghebi
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, Irvine, California 92618, United States.,Department of Pharmaceutical Chemistry, College of Pharmacy, Jazan University, P.O. Box 114, Jazan 45142, Saudi Arabia
| | - Samara Hanna
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, Irvine, California 92618, United States
| | - Saghar Mozaffari
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, Irvine, California 92618, United States
| | - Simin Rahighi
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, Irvine, California 92618, United States
| | - Rakesh K Tiwari
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, Irvine, California 92618, United States
| | - Keykavous Parang
- Center for Targeted Drug Delivery, Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, Irvine, California 92618, United States
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Kotynia A, Janek T, Czyżnikowska Ż, Bielińska S, Kamysz W, Brasuń J. The Analysis of Cu(II)/Zn(II) Cyclopeptide System as Potential Cu,ZnSOD Mimic Center. Int J Pept Res Ther 2017; 23:431-439. [PMID: 29170621 PMCID: PMC5681615 DOI: 10.1007/s10989-017-9574-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2017] [Indexed: 01/24/2023]
Abstract
In this paper are presented the features of copper (II) and zinc (II) heteronuclear complexes of the cyclic peptide—c(HKHGPG)2. The coordination properties of ligand were studied by potentiometric, UV–Vis and CD spectroscopic methods. These experiments were carried out in aqueous solutions at 298 K depending on pH. It turned out that in a physiological pH dominates Cu(II)/Zn(II) complex ([CuZnL]4+) which could mimic the active center of superoxide dismutase (Cu,ZnSOD). In next step we performed in vitro research on Cu,ZnSOD activity for [CuZnL]4+ complex existing in 7.4 pH by the method of reduction of nitroblue tetrazolium (NBT). Also mono- and di-nuclear copper (II) complexes of this ligand were examined. The ability of inhibition free radical reaction were compared for all complexes. The results of these studies show that Cu(II) mono-, di-nuclear and Cu(II)/Zn(II) complexes becoming to new promising synthetic superoxide dismutase mimetics, and should be considered for further biological assays.
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Affiliation(s)
- Aleksandra Kotynia
- Department of Inorganic Chemistry, Wroclaw Medical University, Borowska 211a, 50-552 Wroclaw, Poland
| | - Tomasz Janek
- Department of Inorganic Chemistry, Wroclaw Medical University, Borowska 211a, 50-552 Wroclaw, Poland
| | - Żaneta Czyżnikowska
- Department of Inorganic Chemistry, Wroclaw Medical University, Borowska 211a, 50-552 Wroclaw, Poland
| | - Sylwia Bielińska
- Department of Inorganic Chemistry, Medical University of Gdansk, 80-416 Gdansk, Poland
| | - Wojciech Kamysz
- Department of Inorganic Chemistry, Medical University of Gdansk, 80-416 Gdansk, Poland
| | - Justyna Brasuń
- Department of Inorganic Chemistry, Wroclaw Medical University, Borowska 211a, 50-552 Wroclaw, Poland
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Hanold LE, Fulton MD, Kennedy EJ. Targeting kinase signaling pathways with constrained peptide scaffolds. Pharmacol Ther 2017; 173:159-170. [PMID: 28185915 DOI: 10.1016/j.pharmthera.2017.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Kinases are amongst the largest families in the human proteome and serve as critical mediators of a myriad of cell signaling pathways. Since altered kinase activity is implicated in a variety of pathological diseases, kinases have become a prominent class of proteins for targeted inhibition. Although numerous small molecule and antibody-based inhibitors have already received clinical approval, several challenges may still exist with these strategies including resistance, target selection, inhibitor potency and in vivo activity profiles. Constrained peptide inhibitors have emerged as an alternative strategy for kinase inhibition. Distinct from small molecule inhibitors, peptides can provide a large binding surface area that allows them to bind shallow protein surfaces rather than defined pockets within the target protein structure. By including chemical constraints within the peptide sequence, additional benefits can be bestowed onto the peptide scaffold such as improved target affinity and target selectivity, cell permeability and proteolytic resistance. In this review, we highlight examples of diverse chemistries that are being employed to constrain kinase-targeting peptide scaffolds and highlight their application to modulate kinase signaling as well as their potential clinical implications.
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Affiliation(s)
- Laura E Hanold
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, United States
| | - Melody D Fulton
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, United States
| | - Eileen J Kennedy
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602, United States.
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5
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Affiliation(s)
- Ramesh Chingle
- Département de Chimie, Université de Montréal, C.P.
6128, Succursale Centre-Ville, Montréal, Québec Canada H3C 3J7
| | - William D. Lubell
- Département de Chimie, Université de Montréal, C.P.
6128, Succursale Centre-Ville, Montréal, Québec Canada H3C 3J7
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Nasrolahi Shirazi A, Tiwari RK, Brown A, Mandal D, Sun G, Parang K. Cyclic peptides containing tryptophan and arginine as Src kinase inhibitors. Bioorg Med Chem Lett 2013; 23:3230-4. [PMID: 23602444 PMCID: PMC3660729 DOI: 10.1016/j.bmcl.2013.03.124] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 03/23/2013] [Accepted: 03/27/2013] [Indexed: 11/27/2022]
Abstract
A number of cyclic and linear peptides containing various combinations of amino acids were evaluated for their Src kinase inhibitory potency. Among all the peptides, cyclic decapeptide C[RW]5 containing alternative arginine (R) and tryptophan (W) residues was found to be the most potent Src kinase inhibitor. C[RW]5 showed higher inhibitory activity (IC50=2.8 μM) than C[KW]5, L(KW)5, C[RW]4, and C[RW]3 with IC50 values of 46.9, 69.1, 21.5, and 25.0 μM, respectively, as determined in a fluorescence intensity-based assay. Thus, the cyclic nature, the presence of arginine, ring size, and the number of amino acids in the structure of the peptide were found to be critical in Src kinase inhibitory potency. The IC50 value of C[RW]5 was found to be 0.8 μM in a radioactive assay using [γ-(32)P]-ATP and polyE4Y as the substrate. C[RW]5 was a noncompetitive Src kinase inhibitor, showing approximately fourfold more selectivity towards Src than Abl.
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Affiliation(s)
- Amir Nasrolahi Shirazi
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
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Flexible or fixed: a comparative review of linear and cyclic cancer-targeting peptides. Future Med Chem 2012; 4:1601-18. [PMID: 22917248 DOI: 10.4155/fmc.12.75] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Peptides can serve as versatile cancer-targeting ligands and have been used for clinically relevant applications such as cancer imaging and therapy. A current and long-standing focus within peptide research is the creation of structurally constrained peptides generated through cyclization. Cyclization is envisioned to enhance the selective binding, uptake, potency and stability of linear precursors. This review compares closely related linear and cyclic peptides in these respects. Peptide cyclization generally improves the selective binding and stability of linear precursors; however, not all cyclization strategies and constrained geometries enhance these properties to the same extent. In some instances, linear analogues actually have better cancer-targeting properties compared with their cyclic counterparts. Although cyclization does not necessarily improve the cancer-targeting properties of linear analogues, cyclic peptides may obtain properties that allow them to be used for additional applications. This review aims to convey the advantages and limitations of cyclic cancer-targeting peptides.
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8
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Rafinejad A, Fallah-Tafti A, Tiwari R, Shirazi AN, Mandal D, Shafiee A, Parang K, Foroumadi A, Akbarzadeh T. 4-Aryl-4H-naphthopyrans derivatives: one-pot synthesis, evaluation of Src kinase inhibitory and anti-proliferative activities. ACTA ACUST UNITED AC 2012; 20:100. [PMID: 23351304 PMCID: PMC3599540 DOI: 10.1186/2008-2231-20-100] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 12/21/2012] [Indexed: 11/14/2022]
Abstract
Background A series of 2-amino-4-aryl-4H-benzo[h or f]chromene-3-carbonitrile derivatives were synthesized and evaluated for inhibition of Src kinase and cell proliferation in breast carcinoma (BT-20) cell lines. Methods The one-pot, three-component reaction of α or β-naphthol, malonitrile and an aromatic aldehyde in the presence of diammonium hydrogen phosphate was afforded the corresponding 2-amino-4-aryl-4H-benzo[h or f]chromene-3-carbonitrile derivatives, All target compounds were evaluated for inhibition of Src kinase and cell proliferation in breast carcinoma (BT-20) cell lines. Results Among all tested compounds, unsubstituted 4-phenyl analog 4a showed Src kinas inhibitory effect with IC50 value of 28.1 μM and was the most potent compound in this series. In general, the compounds were moderately active against BT-20. 3-Nitro-phenyl 4e and 3-pyridinyl 4h derivatives inhibited the cell proliferation of BT-20 cells by 33% and 31.5%, respectively, and found to be more potent compared to doxorubicin (25% inhibition of cell growth). Conclusion The data indicate that 4-aryl-4H-naphthopyrans scaffold has the potential to be optimized further for designing more potent Src kinase inhibitors and/or anticancer lead compounds.
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Affiliation(s)
- Ali Rafinejad
- Department of Medicinal Chemistry, Faculty of Pharmacy and Drug Design & Development Research Center, Tehran University of Medical Sciences, Tehran, Iran.
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Thiazolyl N-benzyl-substituted acetamide derivatives: synthesis, Src kinase inhibitory and anticancer activities. Eur J Med Chem 2011; 46:4853-8. [PMID: 21852023 DOI: 10.1016/j.ejmech.2011.07.050] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 06/12/2011] [Accepted: 07/14/2011] [Indexed: 11/23/2022]
Abstract
KX2-391 (KX-01/Kinex Pharmaceuticals), N-benzyl-2-(5-(4-(2-morpholinoethoxy)phenyl)pyridin-2-yl)acetamide, is a highly selective Src substrate binding site inhibitor. To understand better the role of pyridine ring and N-benzylsubstitution in KX2-391 and establish the structure-activity relationship, a number of N-benzyl substituted (((2-morpholinoethoxy)phenyl)thiazol-4-yl)acetamide derivatives containing thiazole instead of pyridine were synthesized and evaluated for Src kinase inhibitory activities. The unsubstituted N-benzyl derivative (8a) showed the inhibition of c-Src kinase with GI(50) values of 1.34 μM and 2.30 μM in NIH3T3/c-Src527F and SYF/c-Src527F cells, respectively. All the synthesized compounds were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), breast carcinoma (BT-20), and leukemia (CCRF-CEM) cells. 4-Fluorobenzylthiazolyl derivative 8b exhibited 64-71% inhibition in the cell proliferation of BT-20 and CCRF cells at concentration of 50 μM.
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3-substitued indoles: one-pot synthesis and evaluation of anticancer and Src kinase inhibitory activities. Bioorg Med Chem Lett 2011; 21:3511-4. [PMID: 21612925 DOI: 10.1016/j.bmcl.2011.05.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 05/02/2011] [Indexed: 11/22/2022]
Abstract
An efficient and economical method was developed for the synthesis of 3-substituted indoles by one-pot three-component coupling reaction of a substituted or unsubstituted benzaldehyde, N-methylaniline, and indole or N-methylindole using Yb(OTf)(3)-SiO(2) as a catalyst. All the synthesized compounds were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), human ovarian adenocarcinoma (SK-OV-3), and c-Src kinase activity. The 4-methylphenyl (4o and 4p) and 4-methoxyphenyl (4q) indole derivatives inhibited the cell proliferation of SK-OV-3 and HT-29 cells by 70-77% at a concentration of 50 μM. The unsubstituted phenyl (4d) and 3-nitrophenyl (4l) derivatives showed the inhibition of c-Src kinase with IC(50) values of 50.6 and 58.3 μM, respectively.
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Kumar A, Ahmad I, Chhikara BS, Tiwari R, Mandal D, Parang K. Synthesis of 3-phenylpyrazolopyrimidine-1,2,3-triazole conjugates and evaluation of their Src kinase inhibitory and anticancer activities. Bioorg Med Chem Lett 2011; 21:1342-6. [PMID: 21300544 DOI: 10.1016/j.bmcl.2011.01.047] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Revised: 01/10/2011] [Accepted: 01/12/2011] [Indexed: 11/24/2022]
Abstract
A series of two classes of 3-phenylpyrazolopyrimidine-1,2,3-triazole conjugates were synthesized using click chemistry approach. All compounds were evaluated for inhibition of Src kinase and human ovarian adenocarcinoma (SK-Ov-3), breast carcinoma (MDA-MB-361), and colon adenocarcinoma (HT-29). Hexyl triazolyl-substituted 3-phenylpyrazolopyrimidine exhibited inhibition of Src kinase with an IC(50) value of 5.6 μM. 4-Methoxyphenyl triazolyl-substituted 3-phenylpyrazolopyrimidine inhibited the cell proliferation of HT-29 and SK-Ov-3 by 73% and 58%, respectively, at a concentration of 50 μM.
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Affiliation(s)
- Anil Kumar
- Department of Chemistry, Birla Institute of Technology and Science, Pilani, Rajasthan, India
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Jagasia R, Holub JM, Bollinger M, Kirshenbaum K, Finn MG. Peptide cyclization and cyclodimerization by Cu(I)-mediated azide-alkyne cycloaddition. J Org Chem 2009; 74:2964-74. [PMID: 19309103 PMCID: PMC2677176 DOI: 10.1021/jo802097m] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Head-to-tail cyclodimerization of resin-bound oligopeptides bearing azide and alkyne groups occurs readily by 1,3-dipolar cycloaddition upon treatment with Cu(I). The process was found to be independent of peptide sequence, sensitive to the proximity of the alkyne to the resin, sensitive to solvent composition, facile for alpha- and beta-peptides but not for gamma-peptides, and inhibited by the inclusion of tertiary amide linkages. Peptides shorter than hexamers were predominantly converted to cyclic monomers. Oligoglycine and oligo(beta-alanine) chains underwent oligomerization by 1,3-dipolar cycloaddition in the absence of a copper catalyst. These results suggest that cyclodimerization depends on the ability of the azido-alkyne peptide to form in-frame hydrogen bonds between chains in order to place the reacting groups in close proximity and lower the entropic penalty for dimerization. The properties of the resin and solvent are crucial, giving rise to a productive balance between swelling and interstrand H-bonding. These findings allow for the design of optimal substrates for triazole-forming ring closure and for the course of the reaction to be controlled by the choice of conditions.
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Affiliation(s)
- Reshma Jagasia
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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Harrison S, Das K, Karim F, Maclean D, Mendel D. Non-ATP-competitive kinase inhibitors – enhancing selectivity through new inhibition strategies. Expert Opin Drug Discov 2008; 3:761-74. [DOI: 10.1517/17460441.3.7.761] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Kumar A, Wang Y, Lin X, Sun G, Parang K. Synthesis and Evaluation of 3-Phenylpyrazolo[3,4-d]pyrimidine-Peptide Conjugates as Src Kinase Inhibitors. ChemMedChem 2007; 2:1346-60. [PMID: 17530729 DOI: 10.1002/cmdc.200700074] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
3-Phenylpyrazolo[3,4-d]pyrimidine (PhPP) derivatives substituted with an alkyl or aryl carboxylic acid at the N1-endocyclic amine, such as PhPP-CH(2)COOH (IC(50)=250 microM), and peptides Ac-CIYKYY (IC(50)=400 microM) and Ac-YIYGSFK (IC(50)=570 microM) were weak inhibitors of polyE(4)Y phosphorylation by active c-Src. A series of PhPP-peptide conjugates were synthesized using PhPP as an ATP mimic and CIYKYY or YIYGSFK as a peptide substrate to improve the inhibitory potency against active c-Src kinase. PhPP derivatives were attached to the N terminus or the side chain of amino acids in the peptide template. Two N-terminal substituted conjugates, PhPP-CH(2)CO-CIYKYY (IC(50)=0.38 microM) and PhPP-CH(2)CO-YIYGSFK (IC(50)=2.7 microM), inhibited the polyE(4)Y phosphorylation by active c-Src significantly higher than that of the parent compounds. The conjugation of PhPP with the peptides produced a synergistic inhibition effect possibly through creation of favorable interactions between the conjugate and the kinase domain as shown by molecular modeling studies.
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Affiliation(s)
- Anil Kumar
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, 41 Lower College Road, Kingston, Rhode Island 02881, USA
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Ahmadibeni Y, Hanley M, White M, Ayrapetov M, Lin X, Sun G, Parang K. Metal-Binding Properties of a Dicysteine-Containing Motif in Protein Tyrosine Kinases. Chembiochem 2007; 8:1592-605. [PMID: 17674392 DOI: 10.1002/cbic.200700242] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Studying the structural consequences of the direct binding of arsenite, cadmium, cobalt, nickel, and lead to a number of protein tyrosine kinases led to the discovery of the metal-binding properties of a dicysteine-containing motif in the C-terminal (CT) lobe of the kinases. Of all the synthesized peptides derived from different domains of c-Src and Csk, only peptides based on a dicysteine-containing motif located in the CT lobe of the kinase domain-CPESLHDLMCQC and CPESLHDLMC in c-Src, and CPPAVYDVMKNC in Csk-exhibited significant conformational changes in the presence of all metals, as shown by circular dichroism (CD) analyses. Furthermore, CD analysis of natural enzymes c-Src, Csk, Fyn, c-Abl, Lck, EGFR, and c-Src domains containing the CT lobe in the presence of metals showed a significant concentration-dependent conformational change. ICP-MS, (113)Cd NMR, (33)S NMR, and/or molecular modeling studies of CPESLHDLMC and CPPAVYDVMKNC confirmed the binding between the free sulfhydryl groups of the cysteine residues and Cd(II) or As(III). UV-titration studies suggested a high-affinity interaction between Cd(II) and As(III) and the peptides (K(d) values in the range of 0.6-18.3 nM).
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Affiliation(s)
- Yousef Ahmadibeni
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, 41 Lower College Road, Kingston, RI 02879, USA
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