51
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Smith SJ, Du K, Radford RJ, Tezcan FA. Functional, metal-based crosslinkers for α-helix induction in short peptides. Chem Sci 2013; 4:3740-3747. [PMID: 24156013 PMCID: PMC3800689 DOI: 10.1039/c3sc50858g] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Many protein-protein interactions that play a central role in cellular processes involve α-helical domains. Consequently, there has been great interest in developing strategies for stabilizing short peptides in α-helical conformations toward the inhibition and interrogation of protein-protein interactions. Here, we show that tridentate Hybrid Coordination Motifs (HCMs), which consist of a natural (histidine, His) and an unnatural (8-hydroxyquinoline, Quin) metal binding functionality, can bind divalent metal ions with high affinity and thereby induce/stabilize an α-helical configuration in short peptide sequences. The Quin functionality is readily introduced onto peptide platforms both during or after solid-state peptide synthesis, demonstrating the preparative versatility of HCMs. A systematic study involving a series of HCM-bearing peptides has revealed the critical importance of the length of the linkage between the Quin moiety and the peptide backbone as well as the metal coordination geometry in determining the extent of α-helix induction. Through ZnII coordination or modification with ReI(Quin)(CO)3, the HCM-bearing peptides can be rendered luminescent in the visible region, thus showing that HCMs can be exploited to simultaneously introduce structure and functionality into short peptides.
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Affiliation(s)
- Sarah J Smith
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0356
| | - Kang Du
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0356
| | - Robert J Radford
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0356
| | - F Akif Tezcan
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0356
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52
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Haney CM, Horne WS. Oxime side-chain cross-links in an α-helical coiled-coil protein: structure, thermodynamics, and folding-templated synthesis of bicyclic species. Chemistry 2013; 19:11342-51. [PMID: 23843311 DOI: 10.1002/chem.201300506] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Indexed: 01/11/2023]
Abstract
Covalent side-chain cross-links are a versatile method to control peptide folding, particularly when α-helical secondary structure is the target. Here, we examine the application of oxime bridges, formed by the chemoselective reaction between aminooxy and aldehyde side chains, for the stabilization of a helical peptide involved in a protein-protein complex. A series of sequence variants of the dimeric coiled coil GCN4-p1 bearing oxime bridges at solvent-exposed positions were prepared and biophysically characterized. Triggered unmasking of a side-chain aldehyde in situ and subsequent cyclization proceed rapidly and cleanly at pH 7 in the folded protein complex. Comparison of folding thermodynamics among a series of different oxime bridges show that the cross links are consistently stabilizing to the coiled coil, with the extent of stabilization sensitive to the exact size and structure of the macrocycle. X-ray crystallographic analysis of a coiled coil with the best cross link in place and a second structure of its linear precursor show how the bridge is accommodated into an α-helix. Preparation of a bicyclic oligomer by simultaneous formation of two linkages in situ demonstrates the potential use of triggered oxime formation to both trap and stabilize a particular peptide folded conformation in the bound state.
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Affiliation(s)
- Conor M Haney
- Department of Chemistry, University of Pittsburgh, 219 Parkman Ave., Pittsburgh, PA 15260, USA
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53
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Jamieson AG, Boutard N, Sabatino D, Lubell WD. Peptide scanning for studying structure-activity relationships in drug discovery. Chem Biol Drug Des 2013; 81:148-65. [PMID: 23253136 DOI: 10.1111/cbdd.12042] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Peptide-based therapeutics have grown in importance over the last few decades. Furthermore, peptides have been extensively used as lead compounds in the drug discovery process to investigate the nature of chemical space required for molecular recognition and activity at a variety of targets. This critical commentary reviews scanning techniques, which employ natural and non-proteinogenic amino acids to facilitate understanding of structural requirements for peptide biological activity. The value of sequence analysis by such methods is highlighted by examples, in which the elements for peptide affinity and activity have been elucidated and employed to prepare peptidomimetic leads for drug development.
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Affiliation(s)
- Andrew G Jamieson
- Department of Chemistry, University of Leicester, Leicester LE1 7RH, UK
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54
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Jo H, Meinhardt N, Wu Y, Kulkarni S, Hu X, Low KE, Davies PL, DeGrado WF, Greenbaum DC. Development of α-helical calpain probes by mimicking a natural protein-protein interaction. J Am Chem Soc 2012; 134:17704-13. [PMID: 22998171 PMCID: PMC3523126 DOI: 10.1021/ja307599z] [Citation(s) in RCA: 210] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We have designed a highly specific inhibitor of calpain by mimicking a natural protein-protein interaction between calpain and its endogenous inhibitor calpastatin. To enable this goal we established a new method of stabilizing an α-helix in a small peptide by screening 24 commercially available cross-linkers for successful cysteine alkylation in a model peptide sequence. The effects of cross-linking on the α-helicity of selected peptides were examined by CD and NMR spectroscopy, and revealed structurally rigid cross-linkers to be the best at stabilizing α-helices. We applied this strategy to the design of inhibitors of calpain that are based on calpastatin, an intrinsically unstable polypeptide that becomes structured upon binding to the enzyme. A two-turn α-helix that binds proximal to the active site cleft was stabilized, resulting in a potent and selective inhibitor for calpain. We further expanded the utility of this inhibitor by developing irreversible calpain family activity-based probes (ABPs), which retained the specificity of the stabilized helical inhibitor. We believe the inhibitor and ABPs will be useful for future investigation of calpains, while the cross-linking technique will enable exploration of other protein-protein interactions.
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Affiliation(s)
- Hyunil Jo
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94143
| | - Nataline Meinhardt
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104
| | - Yibing Wu
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94143
| | - Swapnil Kulkarni
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104
| | - Xiaozhen Hu
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94143
| | - Kristin E. Low
- Department of Biochemistry and Protein Function Discovery, Kingston, Ontario, K7L 3N6 (Canada)
| | - Peter L. Davies
- Department of Biochemistry and Protein Function Discovery, Kingston, Ontario, K7L 3N6 (Canada)
| | - William F. DeGrado
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94143
| | - Doron C. Greenbaum
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104
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55
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Demizu Y, Nagoya S, Doi M, Sato Y, Tanaka M, Kurihara M. Twisted structure of a cyclic hexapeptide containing a combination of alternating L-Leu-D-Leu-Aib segments. J Org Chem 2012; 77:9361-5. [PMID: 23006337 DOI: 10.1021/jo301509c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We designed and synthesized a C(2)-symmetric cyclic hexapeptide, cyclo(L-Leu-D-Leu-Aib)(2) (2), which contains L- and D-amino acids and achiral Aib residues. The conformation of 2 was analyzed in the crystalline state and in solution, which was a unique figure-eight-shaped conformation.
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Affiliation(s)
- Yosuke Demizu
- Division of Organic Chemistry, National Institute of Health Sciences, Tokyo 158-8501, Japan.
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56
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Cheng RP, Wang WR, Girinath P, Yang PA, Ahmad R, Li JH, Hart P, Kokona B, Fairman R, Kilpatrick C, Argiros A. Effect of Glutamate Side Chain Length on Intrahelical Glutamate–Lysine Ion Pairing Interactions. Biochemistry 2012; 51:7157-72. [DOI: 10.1021/bi300655z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Richard P. Cheng
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Wei-Ren Wang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Prashant Girinath
- Department of Chemistry, University
at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
| | - Po-An Yang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Raheel Ahmad
- Department of Chemistry, University
at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
| | - Jhe-Hao Li
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Pier Hart
- Department of Biology, Haverford College, Haverford, Pennsylvania 19041, United
States
| | - Bashkim Kokona
- Department of Biology, Haverford College, Haverford, Pennsylvania 19041, United
States
| | - Robert Fairman
- Department of Biology, Haverford College, Haverford, Pennsylvania 19041, United
States
| | - Casey Kilpatrick
- Department of Chemistry, University
at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
| | - Annmarie Argiros
- Department of Chemistry, University
at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
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57
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Abstract
Developing short peptides into useful probes and therapeutic leads remains a difficult challenge. Structural rigidification is a proven method for improving the properties of short peptides. In this work, we report a strategy for stabilizing peptide macrocycles by introducing side-chain-to-side-chain staples to produce peptide bicycles with higher affinity, selectivity, and resistance to degradation. We have applied this strategy to G1, an 11-residue peptide macrocycle that binds the Src homology 2 (SH2) domain of growth-factor-bound protein 2 (Grb2). Several homodetic peptide bicycles were synthesized entirely on-resin with high yields. Two rounds of iterative design produced peptide bicycle BC1, which is 60 times more potent than G1 and 200 times more selective. Moreover, BC1 is completely intact after 24 hours in buffered human serum, conditions under which G1 is completely degraded. Our peptide-bicycle approach holds promise for the development of selective inhibitors of SH2 domains and other phosophotyrosine (pTyr)-binding proteins, as well as inhibitors of many other protein-protein interactions.
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Affiliation(s)
- Justin S. Quartararo
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
| | - Pianpian Wu
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
| | - Joshua A. Kritzer
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
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58
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Abstract
Recent success stories concerning the targeting of protein-protein interactions (PPIs) have led to an increased focus on this challenging target class for drug discovery. This article explores various avenues to assess the druggability of PPIs and describes a druggability decision flow chart, which can be applied to any PPI target. This flow chart not only covers small molecules but also peptidomimetics, peptides and conformationally restricted peptides as potential modalities for targeting PPIs. Additionally, a retrospective analysis of PPI druggability using various computational tools is summarized. The application of a systematic approach as presented in this paper will increase confidence that modulators (e.g., small organic molecules or peptides) can ultimately be identified for a particular target before a decision is made to commit significant discovery resources.
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59
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Mahon AB, Arora PS. End-Capped α-Helices as Modulators of Protein Function. DRUG DISCOVERY TODAY. TECHNOLOGIES 2012; 9:e1-e70. [PMID: 22712023 DOI: 10.1016/j.ddtec.2011.07.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Examination of complexes of proteins with other biomolecules reveals that proteins tend to interact with partners via folded sub-domains, in which the backbone possesses secondary structure. α-Helices, the largest class of protein secondary structures, play fundamental roles in a multitude of highly specific protein-protein and protein-nucleic acids interactions. Herein, we describe the potential of a helix nucleation strategy to afford modulators of protein-protein interactions.
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Affiliation(s)
- Andrew B Mahon
- Department of Chemistry, New York University, New York, NY 10003
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60
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Almeida AM, Li R, Gellman SH. Parallel β-sheet secondary structure is stabilized and terminated by interstrand disulfide cross-linking. J Am Chem Soc 2012; 134:75-8. [PMID: 22148521 PMCID: PMC3266109 DOI: 10.1021/ja208856c] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Disulfide bonds between Cys residues in adjacent strands of parallel β-sheets are rare among proteins, which suggests that parallel β-sheet structure is not stabilized by such disulfide cross-links. We report experimental results that show, surprisingly, that an interstrand disulfide bond can stabilize parallel β-sheets formed by an autonomously folding peptide in aqueous solution. NMR analysis reveals that parallel β-sheet structure is terminated beyond the disulfide bond, which causes deviation from the extended backbone conformation at one of the Cys residues.
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Affiliation(s)
- Aaron M. Almeida
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wi, 53706 (USA)
| | - Rebecca Li
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wi, 53706 (USA)
| | - Samuel H. Gellman
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Ave., Madison, Wi, 53706 (USA)
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61
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Huber K, Ghosh S, Hardy JA. Inhibition of caspase-9 by stabilized peptides targeting the dimerization interface. Biopolymers 2012; 98:451-65. [PMID: 23203690 PMCID: PMC3544179 DOI: 10.1002/bip.22080] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/29/2012] [Accepted: 04/04/2012] [Indexed: 11/09/2022]
Abstract
Caspases comprise a family of dimeric cysteine proteases that control apoptotic programmed cell death and are therefore critical in both organismal development and disease. Specific inhibition of individual caspases has been repeatedly attempted, but has not yet been attained. Caspase-9 is an upstream or initiator caspase that is regulated differently from all other caspases, as interaction with natural inhibitor X-linked inhibitor of apoptosis protein (XIAP)-baculovirus inhibitory repeat 3 (BIR3) occurs at the dimer interface maintaining caspase-9 in an inactive monomeric state. One route to caspase-9-specific inhibition is to mimic this interaction, which has been localized to the α5 helix of XIAP-BIR3. We have developed three types of stabilized peptides derived from the α5 helix, using incorporation of aminoisobutyric acid, the avian pancreatic polypeptide (aPP)-scaffold or aliphatic staples. The stabilized peptides are helical in solution and achieve up to 32 μM inhibition, indicating that this allosteric site at the caspase-9 dimerization interface is regulatable with low-molecular weight synthetic ligands and is thus a druggable site. The most potent peptides against caspase-9 activity are the aPP-scaffolded peptides. Other caspases, which are not regulated by dimerization, should not be inactivated by these peptides. Given that all of the peptides attain helical structures but cannot recapitulate the high-affinity inhibition of the intact BIR3 domain, it has become clear that interactions of caspase-9 with the BIR3 exosite are essential for high-affinity binding. These results explain why the full XIAP-BIR3 domain is required for maximal inhibition and suggest a path forward for achieving allosteric inhibition at the dimerization interface using peptides or small molecules.
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Affiliation(s)
- Kristen Huber
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003
| | | | - Jeanne A. Hardy
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003
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62
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Mahon AB, Miller SE, Joy ST, Arora PS. Rational Design Strategies for Developing Synthetic Inhibitors of Helical Protein Interfaces. TOPICS IN MEDICINAL CHEMISTRY 2012. [DOI: 10.1007/978-3-642-28965-1_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
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63
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Conjugation of spermine enhances cellular uptake of the stapled peptide-based inhibitors of p53-Mdm2 interaction. Bioorg Med Chem Lett 2011; 21:7412-5. [PMID: 22047690 DOI: 10.1016/j.bmcl.2011.10.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/30/2011] [Accepted: 10/04/2011] [Indexed: 11/23/2022]
Abstract
We report the first synthesis of the C-terminally spermine-conjugated stapled peptide-based inhibitors of the p53-Mdm2 interaction. Subsequent biological, biophysical and cellular uptake assays with the spermine-conjugated stapled peptides revealed that spermine conjugation minimally affects biological activity while significantly increases peptide helicity and cellular uptake without apparent cytotoxicity.
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64
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Enantioselective epoxidation of α,β-unsaturated ketones catalyzed by stapled helical l-Leu-based peptides. Tetrahedron 2011. [DOI: 10.1016/j.tet.2011.06.075] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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65
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Estieu-Gionnet K, Guichard G. Stabilized helical peptides: overview of the technologies and therapeutic promises. Expert Opin Drug Discov 2011; 6:937-63. [PMID: 22646216 DOI: 10.1517/17460441.2011.603723] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Helical structures in proteins and naturally occurring peptides play a major role in a variety of biological processes by mediating interactions with proteins and other macromolecules such as nucleic acids and lipid membranes. The use of short synthetic peptides encompassing helical segments to modulate or disrupt such interactions, when associated with human diseases, represents great pharmacological interest. AREAS COVERED Multiple chemical approaches have been developed to increase the conformational and metabolic stabilities of helical peptides and to improve their biomedical potential. After a brief overview of these technologies and the most recent developments, this review will focus on the main therapeutic areas and targets and will discuss their promise. EXPERT OPINION Potential benefits associated with increased helix stability extend beyond simple affinity enhancement. Some peptidomimetic helices are being endowed with features desirable for cellular activity such as increased resistance to proteolysis and/or cell permeability. Recent advances in the field of peptide and related peptidomimetic helices are not just conceptual, but are likely to be of practical utility in the process of optimizing peptides as clinical candidates, and developing medium-size therapeutics.
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Affiliation(s)
- Karine Estieu-Gionnet
- Institut Européen de Chimie et Biologie , Université de Bordeaux, CNRS UMR 5248, CBMN, 2 rue R. Escarpit, 33607 Pessac , France
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66
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Muppidi A, Wang Z, Li X, Chen J, Lin Q. Achieving cell penetration with distance-matching cysteine cross-linkers: a facile route to cell-permeable peptide dual inhibitors of Mdm2/Mdmx. Chem Commun (Camb) 2011; 47:9396-8. [PMID: 21773579 DOI: 10.1039/c1cc13320a] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the design of bisarylmethylene bromides as a new class of rigid, distance-matching cysteine cross-linkers. By cross-linking a peptide dual inhibitor of Mdm2/Mdmx containing cysteines at i,i+7 positions, dramatic enhancement in cell permeability was achieved, along with increased helicity and biological activity.
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Affiliation(s)
- Avinash Muppidi
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260, USA
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67
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Abstract
Many "new generation" peptidomimetics are designed to present amino acid side chains only; they do not have structural features that resemble peptide main chains. These types of molecules have frequently been presented in the literature as mimics of specific secondary structures. However, many "side-chain only" peptidomimetics do not rest in single conformational states, but exist in a limited number of freely interconverting forms. These different conformations may resemble different secondary structures, so referring to them as, for instance, turn- or helical-mimics understates the ways they could adapt to various binding situations. Sets of scaffolds that can be used to mimic aspects of nearly every secondary structure, i.e. universal peptidomimetics, can be constructed. These may assume a privileged place in library design, particularly in high throughput screening for pharmacological probes for which binding conformations, or even the target itself, is unknown at the time the library is designed (critical review, 101 references).
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Affiliation(s)
- Eunhwa Ko
- Texas A & M University, Chemistry Department, P.O. Box 30012, College Station, Texas 77842, USA
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68
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Lee TK, Ahn JM. Solid-phase synthesis of tris-benzamides as α-helix mimetics. ACS COMBINATORIAL SCIENCE 2011; 13:107-11. [PMID: 21395339 DOI: 10.1021/co100056c] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Small molecules mimicking α-helices are of great interest since numerous protein-protein interactions use helical structures at the interface. With a goal of generating libraries of α-helix mimetics, an efficient solid-phase synthetic method was developed to produce tris-benzamides. The tris-benzamide scaffold was designed to place three side-chain functional groups found at the i, i + 4, and i + 7 positions of an α-helix, emulating one helical face. The synthetic strategy involves simple and iterative reactions of removal of an allyl ester, formation of an amide bond via an O → N acyl migration, and an O-alkylation. A small library of twenty tris-benzamides containing a variety of functional groups was prepared in high purity (83-99%) to demonstrate the versatility of the synthetic approach. This methodology allowed the facile and rapid construction of α-helix mimetics that would facilitate the identification of small molecules for target proteins.
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Affiliation(s)
- Tae-Kyung Lee
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Jung-Mo Ahn
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
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69
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Guarracino DA, Bullock BN, Arora PS. Mini review: protein-protein interactions in transcription: a fertile ground for helix mimetics. Biopolymers 2011; 95:1-7. [PMID: 20882600 DOI: 10.1002/bip.21546] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Designed ligands that inhibit protein-protein interactions involved in gene expression are valuable as reagents for genomics research and as leads for drug discovery efforts. Selective modulation of protein-protein interactions has proven to be a daunting task for synthetic ligands; however, the last decade has seen significant advances in inhibitor design, especially for helical protein interfaces. This review discusses examples of transcriptional complexes targeted by designer helices.
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70
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Yamagata N, Demizu Y, Sato Y, Doi M, Tanaka M, Nagasawa K, Okuda H, Kurihara M. Design of a stabilized short helical peptide and its application to catalytic enantioselective epoxidation of (E)-chalcone. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2010.12.030] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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71
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Jacobsen Ø, Maekawa H, Ge NH, Görbitz CH, Rongved P, Ottersen OP, Amiry-Moghaddam M, Klaveness J. Stapling of a 310-Helix with Click Chemistry. J Org Chem 2011; 76:1228-38. [DOI: 10.1021/jo101670a] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Øyvind Jacobsen
- School of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316 Oslo, Norway
| | - Hiroaki Maekawa
- Department of Chemistry, University of California at Irvine, Irvine, California 92697-2025, United States
| | - Nien-Hui Ge
- Department of Chemistry, University of California at Irvine, Irvine, California 92697-2025, United States
| | - Carl Henrik Görbitz
- Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, 0315 Oslo, Norway
| | - Pål Rongved
- School of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316 Oslo, Norway
| | - Ole Petter Ottersen
- Centre for Molecular Biology and Neuroscience, University of Oslo, P.O. Box 1105 Blindern, 0317 Oslo, Norway
| | - Mahmood Amiry-Moghaddam
- Centre for Molecular Biology and Neuroscience, University of Oslo, P.O. Box 1105 Blindern, 0317 Oslo, Norway
| | - Jo Klaveness
- School of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, 0316 Oslo, Norway
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72
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Madden MM, Muppidi A, Li Z, Li X, Chen J, Lin Q. Synthesis of cell-permeable stapled peptide dual inhibitors of the p53-Mdm2/Mdmx interactions via photoinduced cycloaddition. Bioorg Med Chem Lett 2011; 21:1472-5. [PMID: 21277201 DOI: 10.1016/j.bmcl.2011.01.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Revised: 12/27/2010] [Accepted: 01/03/2011] [Indexed: 11/19/2022]
Abstract
We report the first application of a photoinduced 1,3-dipolar cycloaddition reaction to 'staple' a peptide dual inhibitor of the p53-Mdm2/Mdmx interactions. A series of stapled peptide inhibitors were efficiently synthesized and showed excellent dual inhibitory activity in ELISA assay. Furthermore, the positively charged, stapled peptides showed enhanced cellular uptake along with modest in vivo activity.
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Affiliation(s)
- Michael M Madden
- Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14260, USA
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73
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Abstract
This paper concerns peptidomimetic scaffolds that can present side chains in conformations resembling those of amino acids in secondary structures without incurring excessive entropic or enthalpic penalties. Compounds of this type are referred to here as minimalist mimics. The core hypothesis of this paper is that small sets of such scaffolds can be designed to analogue local pairs of amino acids (including noncontiguous ones) in any secondary structure; i.e., they are universal peptidomimetics. To illustrate this concept, we designed a set of four peptidomimetic scaffolds. Libraries based on them were made bearing side chains corresponding to many of the protein-derived amino acids. Modeling experiments were performed to give an indication of kinetic and thermodynamic accessibilities of conformations that can mimic secondary structures. Together, peptidomimetics based on these four scaffolds can adopt conformations that resemble almost any combination of local amino acid side chains in any secondary structure. Universal peptidomimetics of this kind are likely to be most useful in the design of libraries for high-throughput screening against diverse targets. Consequently, data arising from submission of these molecules to the NIH Molecular Libraries Small Molecule Repository (MLSMR) are outlined.
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Affiliation(s)
- Eunhwa Ko
- Department of Chemistry and Laboratory for Molecular Simulation, Texas A&M University, Box 30012, College Station, Texas 77842, United States
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74
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Patgiri A, Menzenski MZ, Mahon AB, Arora PS. Solid-phase synthesis of short α-helices stabilized by the hydrogen bond surrogate approach. Nat Protoc 2010; 5:1857-65. [PMID: 21030960 DOI: 10.1038/nprot.2010.146] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Stabilized α-helices and nonpeptidic helix mimetics have emerged as powerful molecular scaffolds for the discovery of protein-protein interaction inhibitors. Protein-protein interactions often involve large contact areas, which are often difficult for small molecules to target with high specificity. The hypothesis behind the design of stabilized helices and helix mimetics is that these medium-sized molecules may pursue their targets with higher specificity because of a larger number of contacts. This protocol describes an optimized synthetic strategy for the preparation of stabilized α-helices that feature a carbon-carbon linkage in place of the characteristic N-terminal main-chain hydrogen bond of canonical helices. Formation of the carbon-carbon bond is enabled by a microwave-assisted ring-closing metathesis reaction between two terminal olefins on the peptide chain. The outlined strategy allows the synthesis and purification of a hydrogen bond surrogate (HBS) α-helix in ∼ 1 week.
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Affiliation(s)
- Anupam Patgiri
- Department of Chemistry, New York University, New York, USA
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75
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Helix Induction by Dirhodium: Access to Biocompatible Metallopeptides with Defined Secondary Structure. Chemistry 2010; 16:6651-9. [DOI: 10.1002/chem.200903092] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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76
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Norton RS. Mu-conotoxins as leads in the development of new analgesics. Molecules 2010; 15:2825-44. [PMID: 20428082 PMCID: PMC6257286 DOI: 10.3390/molecules15042825] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 04/06/2010] [Accepted: 04/12/2010] [Indexed: 02/02/2023] Open
Abstract
Voltage-gated sodium channels (VGSCs) contain a specific binding site for a family of cone shell toxins known as mu-conotoxins. As some VGSCs are involved in pain perception and mu-conotoxins are able to block these channels, mu-conotoxins show considerable potential as analgesics. Recent studies have advanced our understanding of the three-dimensional structures and structure-function relationships of the mu-conotoxins, including their interaction with VGSCs. Truncated peptide analogues of the native toxins have been created in which secondary structure elements are stabilized by non-native linkers such as lactam bridges. Ultimately, it would be desirable to capture the favourable analgesic properties of the native toxins, in particular their potency and channel sub-type selectivity, in non-peptide mimetics. Such mimetics would constitute lead compounds in the development of new therapeutics for the treatment of pain.
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Affiliation(s)
- Raymond S Norton
- Walter and Eliza Hall Institute of Medical Research, Victoria, Australia.
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77
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Hyun S, Na J, Lee SJ, Park S, Yu J. RNA Grooves Can Accommodate Disulfide-Bridged Bundles of α-Helical Peptides. Chembiochem 2010; 11:767-70. [DOI: 10.1002/cbic.201000072] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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78
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Madden MM, Vera CIR, Song W, Lin Q. Facile synthesis of stapled, structurally reinforced peptide helices via a photoinduced intramolecular 1,3-dipolar cycloaddition reaction. Chem Commun (Camb) 2009:5588-90. [PMID: 19753366 PMCID: PMC2765658 DOI: 10.1039/b912094g] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We report the first use of a photoinduced 1,3-dipolar cycloaddition reaction in "stapling" peptide sidechains to reinforce a model peptide helical structure with moderate to excellent yields; the resulting pyrazoline "staplers" exhibit unique fluorescence useful in a cell permeability study.
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Affiliation(s)
- Michael M. Madden
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260 USA
| | - Claudia I. Rivera Vera
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260 USA
| | - Wenjiao Song
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260 USA
| | - Qing Lin
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260 USA
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79
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Affiliation(s)
- V. Haridas
- Department of Chemistry and School of Biological Sciences, Indian Institute of Technology‐Delhi (IIT‐D), New Delhi‐110 016, India
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80
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Marimganti S, Cheemala MN, Ahn JM. Novel Amphiphilic α-Helix Mimetics Based on a Bis-benzamide Scaffold. Org Lett 2009; 11:4418-21. [PMID: 19719090 DOI: 10.1021/ol901785v] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Srinivasa Marimganti
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080
| | - Murthy N. Cheemala
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080
| | - Jung-Mo Ahn
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080
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81
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Kutchukian PS, Yang JS, Verdine GL, Shakhnovich EI. All-atom model for stabilization of alpha-helical structure in peptides by hydrocarbon staples. J Am Chem Soc 2009; 131:4622-7. [PMID: 19334772 DOI: 10.1021/ja805037p] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent work has shown that the incorporation of an all-hydrocarbon "staple" into peptides can greatly increase their alpha-helix propensity, leading to an improvement in pharmaceutical properties such as proteolytic stability, receptor affinity, and cell permeability. Stapled peptides thus show promise as a new class of drugs capable of accessing intractable targets such as those that engage in intracellular protein-protein interactions. The extent of alpha-helix stabilization provided by stapling has proven to be substantially context dependent, requiring cumbersome screening to identify the optimal site for staple incorporation. In certain cases, a staple encompassing one turn of the helix (attached at residues i and i+4) furnishes greater helix stabilization than one encompassing two turns (i,i+7 staple), which runs counter to expectation based on polymer theory. These findings highlight the need for a more thorough understanding of the forces that underlie helix stabilization by hydrocarbon staples. Here we report all-atom Monte Carlo folding simulations comparing unmodified peptides derived from RNase A and BID BH3 with various i,i+4 and i,i+7 stapled versions thereof. The results of these simulations were found to be in quantitative agreement with experimentally determined helix propensities. We also discovered that staples can stabilize quasi-stable decoy conformations, and that the removal of these states plays a major role in determining the helix stability of stapled peptides. Finally, we critically investigate why our method works, exposing the underlying physical forces that stabilize stapled peptides.
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Affiliation(s)
- Peter S Kutchukian
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, USA
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82
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Development of a bacteriophage-based system for the selection of structured peptides. Anal Biochem 2009; 388:122-7. [DOI: 10.1016/j.ab.2009.01.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 01/28/2009] [Accepted: 01/29/2009] [Indexed: 02/05/2023]
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83
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Nishikawa H, Nakamura S, Kodama E, Ito S, Kajiwara K, Izumi K, Sakagami Y, Oishi S, Ohkubo T, Kobayashi Y, Otaka A, Fujii N, Matsuoka M. Electrostatically constrained α-helical peptide inhibits replication of HIV-1 resistant to enfuvirtide. Int J Biochem Cell Biol 2009; 41:891-9. [DOI: 10.1016/j.biocel.2008.08.039] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 08/19/2008] [Accepted: 08/22/2008] [Indexed: 11/25/2022]
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84
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PATGIRI ANUPAM, JOCHIM ANDREAL, ARORA PARAMJITS. A hydrogen bond surrogate approach for stabilization of short peptide sequences in alpha-helical conformation. Acc Chem Res 2008; 41:1289-300. [PMID: 18630933 PMCID: PMC7189275 DOI: 10.1021/ar700264k] [Citation(s) in RCA: 200] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alpha-helices constitute the largest class of protein secondary structures and play a major role in mediating protein-protein interactions. Development of stable mimics of short alpha-helices would be invaluable for inhibition of protein-protein interactions. This Account describes our efforts in developing a general approach for constraining short peptides in alpha-helical conformations by a main-chain hydrogen bond surrogate (HBS) strategy. The HBS alpha-helices feature a carbon-carbon bond derived from a ring-closing metathesis reaction in place of an N-terminal intramolecular hydrogen bond between the peptide i and i + 4 residues. Our approach is centered on the helix-coil transition theory in peptides, which suggests that the energetically demanding organization of three consecutive amino acids into the helical orientation inherently limits the stability of short alpha-helices. The HBS method affords preorganized alpha-turns to overcome this intrinsic nucleation barrier and initiate helix formation. The HBS approach is an attractive strategy for generation of ligands for protein receptors because placement of the cross-link on the inside of the helix does not block solvent-exposed molecular recognition surfaces of the molecule. Our metathesis-based synthetic strategy utilizes standard Fmoc solid phase peptide synthesis methodology, resins, and reagents and provides HBS helices in sufficient amounts for subsequent biophysical and biological analyses. Extensive conformational analysis of HBS alpha-helices with 2D NMR, circular dichroism spectroscopies and X-ray crystallography confirms the alpha-helical structure in these compounds. The crystal structure indicates that all i and i + 4 C=O and NH hydrogen-bonding partners fall within distances and angles expected for a fully hydrogen-bonded alpha-helix. The backbone conformation of HBS alpha-helix in the crystal structure superimposes with an rms difference of 0.75 A onto the backbone conformation of a model alpha-helix. Significantly, the backbone torsion angles for the HBS helix residues fall within the range expected for a canonical alpha-helix. Thermal and chemical denaturation studies suggest that the HBS approach provides exceptionally stable alpha-helices from a variety of short sequences, which retain their helical conformation in aqueous buffers at exceptionally high temperatures. The high degree of thermal stability observed for HBS helices is consistent with the theoretical predictions for a nucleated helix. The HBS approach was devised to afford internally constrained helices so that the molecular recognition surface of the helix and its protein binding properties are not compromised by the constraining moiety. Notably, our preliminary studies illustrate that HBS helices can target their expected protein receptors with high affinity.
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Affiliation(s)
- ANUPAM PATGIRI
- Department of Chemistry, New York University, New York, New York 10003
| | - ANDREA L. JOCHIM
- Department of Chemistry, New York University, New York, New York 10003
| | - PARAMJIT S. ARORA
- Department of Chemistry, New York University, New York, New York 10003
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85
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Henchey LK, Jochim AL, Arora PS. Contemporary strategies for the stabilization of peptides in the alpha-helical conformation. Curr Opin Chem Biol 2008; 12:692-7. [PMID: 18793750 DOI: 10.1016/j.cbpa.2008.08.019] [Citation(s) in RCA: 237] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 08/01/2008] [Accepted: 08/07/2008] [Indexed: 11/19/2022]
Abstract
Herein we review contemporary synthetic and protein design strategies to stabilize the alpha-helical motif in short peptides and miniature proteins. Advances in organometallic catalyst design, specifically for the olefin metathesis reaction, enable the use of hydrocarbon bridges to either crosslink side chains of specific residues or mimic intramolecular hydrogen bonds with carbon-carbon bonds. The resulting hydrocarbon-stapled and hydrogen bond surrogate alpha-helices provide unique synthetic ligands for targeting biomolecules. In the protein design realm, several classes of miniature proteins that display stable helical domains have been engineered and manipulated with powerful in vitro selection technologies to yield libraries of sequences that retain their helical folds. Rational re-design of these scaffolds provide distinctive reagents for the modulation of protein-protein interactions.
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Affiliation(s)
- Laura K Henchey
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, USA
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86
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Hoang HN, Bryant GK, Kelso MJ, Beyer RL, Appleton TG, Fairlie DP. Linkage isomerism in the binding of pentapeptide Ac-His(Ala)3His-NH2 to (ethylenediamine)palladium(II): effect of the binding mode on peptide conformation. Inorg Chem 2008; 47:9439-49. [PMID: 18788796 DOI: 10.1021/ic800970p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction of the pentapeptide Ac-His1-Ala2-Ala3-Ala4-His5-NH2 (AcHAAAHNH2) (1) with [Pd(en)(ONO2)2] (en = NH2CH2CH2NH2) in either DMF-d(7) or H2O:D2O (90%:10%) gave three linkage isomers of [Pd(en)(AcHAAAHNH2)](2+) (2), 2a, 2b, and 2c, which differ only in which pair of imidazole nitrogen atoms bind to Pd. In the most abundant isomer, 2a, Pd is bound by N1 from each of the two imidazole rings. In the minor isomers 2b and 2c, Pd is bound by N1(His1) and N3(His5) and by N3(His1) and N1(His5), respectively. The reactions of [Pd(en)(ONO2)2] with the N-methylated peptides Ac-(N3-MeHis)-Ala-Ala-Ala-(N3-MeHis)-NH2 (AcH*AAAH*NH2) (3), Ac-(N3-MeHis)-Ala-Ala-Ala-(N1-MeHis)-NH2 (AcH(*)AAAH(#)NH2) (4), and Ac-(N1-MeHis)-Ala-Ala-Ala-(N3-Me-His)-NH2 (AcH(#)AAAH(*)NH2) (5) each gave a single species [Pd(en)(peptide)](2+) in N,N-dimethylformamide (DMF) or aqueous solution, 7, 8, and 9, respectively, with Pd bound by the two nonmethylated imidazole nitrogen atoms in each case. These complexes were analogous to 2a, 2b, and 2c, respectively. Ac-(N1-MeHis)-Ala-Ala-Ala-(N1-MeHis)-NH2 (AcH(#)AAAH(#)NH2) (6) with [Pd(en)(ONO2)2] in DMF slowly gave a single product, [Pd(en)(AcH(#)AAAH(#)NH2)](2+) (10), in which Pd was bound by the N3 of each imidazole ring. The corresponding linkage isomer of 2 was not observed. Complex 10 was also the major product in aqueous solution, but other species were also present. All compounds were exhaustively characterized in solution by multinuclear 1D ((1)H , (13)C, and, with (15)N-labeled ethylenediamine, (15)N) and 2D (correlation spectroscopy, total correlation spectroscopy, transverse rotating-frame Overhauser effect spectroscopy (T-ROESY), heteronuclear multiple-bond correlation, and heteronuclear single quantum coherence) NMR spectra, circular dichroism (CD) spectra, electrospray mass spectroscopy, and reversed-phase high-performance liquid chromatography. ROESY spectra were used to calculate the structure of 2a, which contained a single turn of a peptide alpha helix in both DMF and water, the helix being better defined in DMF. The Pd(en)(2+) moiety was not used in structure calculations, but its location and coordination by one imidazole N1 from each histidine to form a 22-membered metallocycle were unambiguously established. Convergence of the structures was greatest when calculated with two hydrogen-bond constraints (Ala4 peptide NH...OC acetyl and His5 peptide NH...OC-His1) that were indicated by the low temperature dependence of these NH chemical shifts. Vicinal HN-CHalpha coupling constants and chemical shifts of alpha-H atoms were also consistent with a helical conformation. Similar long-range ROE correlations were observed for [Pd(en)(AcH(*)AAAH(*)NH2)](2+) (7), which displayed a CD spectrum in aqueous solution that suggested the presence of some helicity. Long-range ROE correlations were not observed for 8, 9, or 10, but a combination of NMR data and CD spectroscopy was interpreted in terms of the conformational behavior of the coordinated pentapeptide. Only for the linkage isomer [Pd(en)(AcH(*)AAAH(#)NH2)](2+) (8) was there evidence of a contribution from a helical conformation. The data for 8 were interpreted as interconversion between the helix and random coil conformations. Zn(2+) with peptides gave broad NMR peaks attributed to lability of this metal ion, while reactions of cis-[Pt(NH3)2(ONO2)2] were slow, giving a complex mixture of products rather than the macrochelate ring observed with Pd(en)(2+). In summary, these studies indicate that Pd(en)(2+) coordinates to histidine with similar preference for each of the two imidazole nitrogens, enabling the formation of up to four linkage isomers in its complexes with pentapeptides His-xxx-His. Only the N1-N1 linkage isomer that forms a 22-membered macrochelate ring is able to induce an alpha-helical peptide conformation, whereas the 20- and 21-membered rings of linkage isomers do not. This suggests that linkage isomeric mixtures may compromise histidine coordination to metal ions and reduce alpha-helicity.
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Affiliation(s)
- Huy N Hoang
- Centre for Metals in Biology, School of Molecular & Microbial Sciences, The University of Queensland, Brisbane, Qld., Australia 4072
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87
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88
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Matsuzaki K, Okada T, Tsukuda M, Ikeda K, Sohma Y, Chiyomori Y, Taniguchi A, Nakamura S, Ito N, Hayashi Y, Kiso Y. Design, synthesis, and biophysical properties of a helical Aβ1–42 analog: Inhibition of fibrillogenesis and cytotoxicity. Biochem Biophys Res Commun 2008; 371:777-80. [DOI: 10.1016/j.bbrc.2008.04.158] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 04/24/2008] [Indexed: 10/22/2022]
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89
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Che Y, Marshall GR. Privileged scaffolds targeting reverse-turn and helix recognition. Expert Opin Ther Targets 2008; 12:101-14. [PMID: 18076374 DOI: 10.1517/14728222.12.1.101] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Protein-protein interactions dominate molecular recognition in biologic systems. One major challenge for drug discovery arises from the very large surfaces that are characteristic of many protein-protein interactions. OBJECTIVES To identify 'drug-like' small molecule leads capable of modulating protein-protein interactions based on common protein-recognition motifs, such as alpha-helices, beta-strands, reverse-turns and polyproline motifs for example. OVERVIEW Many proteins/peptides are unstructured under physiologic conditions and only fold into ordered structures on binding to their cellular targets. Therefore, preorganization of an inhibitor into its protein-bound conformation reduces the entropy of binding and enhances the relative affinity of the inhibitor. Accordingly, this review describes a general strategy to address the challenge based on the 'privileged structure hypothesis' [Che, PhD thesis, Washington University, 2003] that chemical templates capable of mimicking surfaces of protein-recognition motifs are potential privileged scaffolds as small-molecule inhibitors of protein-protein interactions. The authors highlight recent advances in the design of privileged scaffolds targeting reverse-turn and helical recognition. CONCLUSIONS Privileged scaffolds targeting common protein-recognition motifs are useful to help elucidate the receptor-bound conformation and to provide non-peptidic, bioavailable substructures suitable for optimization to modulate protein-protein interactions.
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Affiliation(s)
- Ye Che
- Washington University, Center for Computational Biology and Department of Biochemistry and Molecular Biophysics, St. Louis, MO 63110, USA
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90
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Liu J, Wang D, Zheng Q, Lu M, Arora PS. Atomic Structure of a Short α-Helix Stabilized by a Main Chain Hydrogen-Bond Surrogate. J Am Chem Soc 2008; 130:4334-7. [DOI: 10.1021/ja077704u] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jie Liu
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021, and Department of Chemistry, New York University, New York, New York 10003
| | - Deyun Wang
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021, and Department of Chemistry, New York University, New York, New York 10003
| | - Qi Zheng
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021, and Department of Chemistry, New York University, New York, New York 10003
| | - Min Lu
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021, and Department of Chemistry, New York University, New York, New York 10003
| | - Paramjit S. Arora
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10021, and Department of Chemistry, New York University, New York, New York 10003
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91
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Zhang H, Zhao Q, Bhattacharya S, Waheed AA, Tong X, Hong A, Heck S, Curreli F, Goger M, Cowburn D, Freed EO, Debnath AK. A cell-penetrating helical peptide as a potential HIV-1 inhibitor. J Mol Biol 2008; 378:565-80. [PMID: 18374356 DOI: 10.1016/j.jmb.2008.02.066] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 02/27/2008] [Accepted: 02/28/2008] [Indexed: 10/22/2022]
Abstract
The capsid domain of the human immunodeficiency virus type 1 (HIV-1) Gag polyprotein is a critical determinant of virus assembly, and is therefore a potential target for developing drugs for AIDS therapy. Recently, a 12-mer alpha-helical peptide (CAI) was reported to disrupt immature- and mature-like capsid particle assembly in vitro; however, it failed to inhibit HIV-1 in cell culture due to its inability to penetrate cells. The same group reported the X-ray crystal structure of CAI in complex with the C-terminal domain of capsid (C-CA) at a resolution of 1.7 A. Using this structural information, we have utilized a structure-based rational design approach to stabilize the alpha-helical structure of CAI and convert it to a cell-penetrating peptide (CPP). The modified peptide (NYAD-1) showed enhanced alpha-helicity. Experiments with laser scanning confocal microscopy indicated that NYAD-1 penetrated cells and colocalized with the Gag polyprotein during its trafficking to the plasma membrane where virus assembly takes place. NYAD-1 disrupted the assembly of both immature- and mature-like virus particles in cell-free and cell-based in vitro systems. NMR chemical shift perturbation analysis mapped the binding site of NYAD-1 to residues 169-191 of the C-terminal domain of HIV-1 capsid encompassing the hydrophobic cavity and the critical dimerization domain with an improved binding affinity over CAI. Furthermore, experimental data indicate that NYAD-1 most likely targets capsid at a post-entry stage. Most significantly, NYAD-1 inhibited a large panel of HIV-1 isolates in cell culture at low micromolar potency. Our study demonstrates how a structure-based rational design strategy can be used to convert a cell-impermeable peptide to a cell-permeable peptide that displays activity in cell-based assays without compromising its mechanism of action. This proof-of-concept cell-penetrating peptide may aid validation of capsid as an anti-HIV-1 drug target and may help in designing peptidomimetics and small molecule drugs targeted to this protein.
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Affiliation(s)
- Hongtao Zhang
- Laboratory of Molecular Modeling and Drug Design, Lindsley F. Kimball Research Institute of the New York Blood Center, 310 E 67th Street, New York, NY 10021, USA
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92
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Synthesis and biophysical characterization of stabilized alpha-helices of BCL-2 domains. Methods Enzymol 2008; 446:369-86. [PMID: 18603134 DOI: 10.1016/s0076-6879(08)01622-4] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Rational design of compounds to mimic the functional domains of BCL-2 family proteins requires chemical reproduction of the biologic complexity afforded by the relatively large and folded surfaces of BCL-2 homology (BH) domain peptide alpha-helices. Because the intermolecular handshakes of BCL-2 proteins are so critical to controlling cellular fate, we undertook the development of a toolbox of peptidic ligands that harness the natural potency and specificity of BH alpha-helices to interrogate and potentially medicate the deregulated apoptotic pathways of human disease. To overcome the classic deficiencies of peptide reagents, including loss of bioactive structure in solution, rapid proteolytic degradation in vivo, and cellular impermeability, we developed a new class of compounds based on hydrocarbon stapling of BH3 death domain peptides. Here we describe the chemical synthesis of Stabilized Alpha-Helices of BCL-2 domains or SAHBs, and the analytical methods used to characterize their secondary structure, proteolytic stability, and cellular penetrance.
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93
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Zhang F, Sadovski O, Xin SJ, Woolley GA. Stabilization of Folded Peptide and Protein Structures via Distance Matching with a Long, Rigid Cross-Linker. J Am Chem Soc 2007; 129:14154-5. [DOI: 10.1021/ja075829t] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fuzhong Zhang
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Oleg Sadovski
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Steven J. Xin
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - G. Andrew Woolley
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
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94
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Wang D, Chen K, Kulp Iii JL, Arora PS. Evaluation of biologically relevant short alpha-helices stabilized by a main-chain hydrogen-bond surrogate. J Am Chem Soc 2007; 128:9248-56. [PMID: 16834399 PMCID: PMC1828873 DOI: 10.1021/ja062710w] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We previously reported the design and synthesis of a new class of artificial alpha-helices in which an N-terminal main-chain hydrogen bond is replaced by a carbon-carbon bond derived from a ring-closing metathesis reaction [Chapman, R. N.; Dimartino, G.; Arora, P. S. J. Am. Chem. Soc. 2004, 126, 12252-12253]. Our initial study utilized an alanine-rich sequence; in the present manuscript we evaluate the potential of this method for the synthesis of very short (10 residues) alpha-helices representing two different biologically relevant alpha-helical domains. We extensively characterized these two sets of artificial helices by NMR and circular dichroism spectroscopies and find that the hydrogen-bond surrogate approach can afford well-defined short alpha-helical structures from sequences that do not spontaneously form alpha-helical conformations.
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Affiliation(s)
- Deyun Wang
- Department of Chemistry, New York University, New York, New York 10003, USA
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95
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Boal AK, Guryanov I, Moretto A, Crisma M, Lanni EL, Toniolo C, Grubbs RH, O'Leary DJ. Facile and E-selective intramolecular ring-closing metathesis reactions in 3(10)-helical peptides: a 3D structural study. J Am Chem Soc 2007; 129:6986-7. [PMID: 17497781 DOI: 10.1021/ja071148m] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Amie K Boal
- Department of Chemistry, Pomona College, Claremont, California 91711, USA
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96
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Wang D, Chen K, Dimartino G, Arora PS. Nucleation and stability of hydrogen-bond surrogate-based alpha-helices. Org Biomol Chem 2007; 4:4074-81. [PMID: 17312961 PMCID: PMC1807155 DOI: 10.1039/b612891b] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have reported a new class of artificial alpha-helices in which a pre-organized alpha-turn nucleates the helical conformation [R. N. Chapman, G. Dimartino, and P. S. Arora, J Am. Chem. Soc., 2004, 126, 12252 and D. Wang, K. Chen, J. L. Kulp, III, and P. S. Arora, J. Am. Chem. Soc., 2006, 128, 9248]. This manuscript describes the effect of the core nucleation template on the overall helicity of the peptides and demonstrates that the macrocycle which most closely mimics the 13-membered hydrogen-bonded alpha-turn in canonical alpha-helices also affords the most stable artificial alpha-helix. We also investigate the stability of these synthetic helices through classical helix-coil parameters and find that the denaturation behavior of HBS alpha-helices agrees with the theoretical properties of a peptide with a well-defined and stable helix nucleus.
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Affiliation(s)
- Deyun Wang
- Department of Chemistry, New York University, New York, NY 10003, USA
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97
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Hamacher K, Hübsch A, McCammon JA. A minimal model for stabilization of biomolecules by hydrocarbon cross-linking. J Chem Phys 2006; 124:164907. [PMID: 16674170 DOI: 10.1063/1.2185645] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Programmed cell death regulating protein motifs play an essential role in the development of an organism, its immune response, and disease-related cellular mechanisms. Among those motifs the BH3 domain of the BCL-2 family is found to be of crucial importance. Recent experiments showed how the isolated, otherwise unstructured BH3 peptide can be modified by a hydrocarbon linkage to regain function. We parametrized a reduced, dynamic model for the stability effects of such covalent cross-linking and confirmed that the model reproduces the reinforcement of the structural stability of the BH3 motif by cross-linking. We show that an analytically solvable model for thermostability around the native state is not capable of reproducing the stabilization effect. This points to the crucial importance of the peptide dynamics and the fluctuations neglected in the analytic model for the cross-linking system to function properly. This conclusion is supported by a thorough analysis of a simulated Go model. The resulting model is suitable for rational design of generic cross-linking systems in silicio.
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Affiliation(s)
- K Hamacher
- Center for Theoretical Biological Physics, University of California at San Diego, La Jolla, California 92093-0374, USA
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98
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Ji H, Shekhtman A, Ghose R, McDonnell JM, Cowburn D. NMR determination that an extended BH3 motif of pro-apoptotic BID is specifically bound to BCL-XL. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2006; 44 Spec No:S101-7. [PMID: 16826547 PMCID: PMC2365746 DOI: 10.1002/mrc.1856] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The BH3 motif of the pro-survival family of proteins, BCL, is also present in pro-apoptotic proteins like BID and BAX. Homo- and hetero-oligomerization interactions of the BH3 motif are generally recognized as the critical component of their apoptotic activities. In full-length BID, the putative hydrophobic binding surface of its BH3 motif is substantially occluded by intramolecular contacts, many of which are removed on BID's transformation to tBID by cleavage with caspase 8, required for tBID's pro-apoptotic action on mitochondria, thereby releasing cytochrome c.
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Affiliation(s)
| | | | | | | | - David Cowburn
- *Correspondence to: David Cowburn, The New York Structural Biology Center, 89 Convent Avenue, New York, NY 10027, USA. E-mail:
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99
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Abstract
The discovery of B-cell lymphoma-2 (BCL-2) over 20 years ago revealed a new paradigm in cancer biology: the development and persistence of cancer can be driven by molecular roadblocks along the natural pathway to cell death. The subsequent identification of an expansive family of BCL-2 proteins provoked an intensive investigation of the interplay among these critical regulators of cell death. What emerged was a compelling tale of guardians and executioners, each participating in a molecular choreography that dictates cell fate. Ten years into the BCL-2 era, structural details defined how certain BCL-2 family proteins interact, and molecular targeting of the BCL-2 family has since become a pharmacological quest. Although many facets of BCL-2 family death signaling remain a mechanistic mystery, small molecules and peptides that effectively target BCL-2 are eliminating the roadblock to cell death, raising hopes for a medical breakthrough in cancer and other diseases of deregulated apoptosis.
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Affiliation(s)
- L D Walensky
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
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100
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Che Y, Brooks BR, Marshall GR. Development of small molecules designed to modulate protein-protein interactions. J Comput Aided Mol Des 2006; 20:109-30. [PMID: 16622794 DOI: 10.1007/s10822-006-9040-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2005] [Accepted: 02/13/2006] [Indexed: 01/25/2023]
Abstract
Protein-protein interactions are ubiquitous, essential to almost all known biological processes, and offer attractive opportunities for therapeutic intervention. Developing small molecules that modulate protein-protein interactions is challenging, owing to the large size of protein-complex interface, the lack of well-defined binding pockets, etc. We describe a general approach based on the "privileged-structure hypothesis" [Che, Ph.D. Thesis, Washington University, 2003] - that any organic templates capable of mimicking surfaces of protein-recognition motifs are potential privileged scaffolds as protein-complex antagonists--to address the challenges inherent in the discovery of small-molecule inhibitors of protein-protein interactions.
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Affiliation(s)
- Ye Che
- Laboratory of Computational Biology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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