1
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Platonov M, Maximyuk O, Rayevsky A, Hurmach V, Iegorova O, Naumchyk V, Bulgakov E, Cherninskyi A, Ozheredov D, Ryabukhin SV, Krishtal O, Volochnyuk DM. 4-(Azolyl)-Benzamidines as a Novel Chemotype for ASIC1a Inhibitors. Int J Mol Sci 2024; 25:3584. [PMID: 38612396 PMCID: PMC11011685 DOI: 10.3390/ijms25073584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 03/03/2024] [Accepted: 03/13/2024] [Indexed: 04/14/2024] Open
Abstract
Acid-sensing ion channels (ASICs) play a key role in the perception and response to extracellular acidification changes. These proton-gated cation channels are critical for neuronal functions, like learning and memory, fear, mechanosensation and internal adjustments like synaptic plasticity. Moreover, they play a key role in neuronal degeneration, ischemic neuronal injury, seizure termination, pain-sensing, etc. Functional ASICs are homo or heterotrimers formed with (ASIC1-ASIC3) homologous subunits. ASIC1a, a major ASIC isoform in the central nervous system (CNS), possesses an acidic pocket in the extracellular region, which is a key regulator of channel gating. Growing data suggest that ASIC1a channels are a potential therapeutic target for treating a variety of neurological disorders, including stroke, epilepsy and pain. Many studies were aimed at identifying allosteric modulators of ASIC channels. However, the regulation of ASICs remains poorly understood. Using all available crystal structures, which correspond to different functional states of ASIC1, and a molecular dynamics simulation (MD) protocol, we analyzed the process of channel inactivation. Then we applied a molecular docking procedure to predict the protein conformation suitable for the amiloride binding. To confirm the effect of its sole active blocker against the ASIC1 state transition route we studied the complex with another MD simulation run. Further experiments evaluated various compounds in the Enamine library that emerge with a detectable ASIC inhibitory activity. We performed a detailed analysis of the structural basis of ASIC1a inhibition by amiloride, using a combination of in silico approaches to visualize its interaction with the ion pore in the open state. An artificial activation (otherwise, expansion of the central pore) causes a complex modification of the channel structure, namely its transmembrane domain. The output protein conformations were used as a set of docking models, suitable for a high-throughput virtual screening of the Enamine chemical library. The outcome of the virtual screening was confirmed by electrophysiological assays with the best results shown for three hit compounds.
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Affiliation(s)
- Maksym Platonov
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Zabolotnogo Str., 150, 03143 Kyiv, Ukraine; (M.P.); (V.H.)
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
| | - Oleksandr Maximyuk
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., 01024 Kyiv, Ukraine; (O.M.); (O.I.); (A.C.); (O.K.)
| | - Alexey Rayevsky
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Zabolotnogo Str., 150, 03143 Kyiv, Ukraine; (M.P.); (V.H.)
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Osypovskoho Str., 2A, 04123 Kyiv, Ukraine;
| | - Vasyl Hurmach
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Zabolotnogo Str., 150, 03143 Kyiv, Ukraine; (M.P.); (V.H.)
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
| | - Olena Iegorova
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., 01024 Kyiv, Ukraine; (O.M.); (O.I.); (A.C.); (O.K.)
| | - Vasyl Naumchyk
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of High Technologies, Taras Shevchenko National University of Kyiv, Volodymyrska Street 60, 01601 Kyiv, Ukraine
| | - Elijah Bulgakov
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Osypovskoho Str., 2A, 04123 Kyiv, Ukraine;
| | - Andrii Cherninskyi
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., 01024 Kyiv, Ukraine; (O.M.); (O.I.); (A.C.); (O.K.)
| | - Danil Ozheredov
- Institute of Food Biotechnology and Genomics, National Academy of Sciences of Ukraine, Osypovskoho Str., 2A, 04123 Kyiv, Ukraine;
| | - Serhiy V. Ryabukhin
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of High Technologies, Taras Shevchenko National University of Kyiv, Volodymyrska Street 60, 01601 Kyiv, Ukraine
- Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Academik Kukhar Str., 02660 Kyiv, Ukraine
| | - Oleg Krishtal
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., 01024 Kyiv, Ukraine; (O.M.); (O.I.); (A.C.); (O.K.)
| | - Dmytro M. Volochnyuk
- Enamine Ltd., 78 Winston Churchill Str., 02660 Kyiv, Ukraine; (V.N.); (E.B.); (D.M.V.)
- Institute of High Technologies, Taras Shevchenko National University of Kyiv, Volodymyrska Street 60, 01601 Kyiv, Ukraine
- Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Academik Kukhar Str., 02660 Kyiv, Ukraine
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2
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Thakkar R, Upreti D, Ishiguro S, Tamura M, Comer J. Computational design of a cyclic peptide that inhibits the CTLA4 immune checkpoint. RSC Med Chem 2023; 14:658-670. [PMID: 37122540 PMCID: PMC10131585 DOI: 10.1039/d2md00409g] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
Proteins involved in immune checkpoint pathways, such as CTLA4, PD1, and PD-L1, have become important targets for cancer immunotherapy; however, development of small molecule drugs targeting these pathways has proven difficult due to the nature of their protein-protein interfaces. Here, using a hierarchy of computational techniques, we design a cyclic peptide that binds CTLA4 and follow this with experimental verification of binding and biological activity, using bio-layer interferometry, cell culture, and a mouse tumor model. Beginning from a template excised from the X-ray structure of the CTLA4:B7-2 complex, we generate several peptide sequences using flexible docking and modeling steps. These peptides are cyclized head-to-tail to improve structural and proteolytic stability and screened using molecular dynamics simulation and MM-GBSA calculation. The standard binding free energies for shortlisted peptides are then calculated in explicit-solvent simulation using a rigorous multistep technique. The most promising peptide, cyc(EIDTVLTPTGWVAKRYS), yields the standard free energy -6.6 ± 3.5 kcal mol-1, which corresponds to a dissociation constant of ∼15 μmol L-1. The binding affinity of this peptide for CTLA4 is measured experimentally (31 ± 4 μmol L-1) using bio-layer interferometry. Treatment with this peptide inhibited tumor growth in a co-culture of Lewis lung carcinoma (LLC) cells and antigen primed T cells, as well as in mice with an orthotropic Lewis lung carcinoma allograft model.
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Affiliation(s)
- Ravindra Thakkar
- Department of Anatomy and Physiology, Kansas State University 1620 Denison Avenue Manhattan Kansas USA +1 785 532 6311
| | - Deepa Upreti
- Department of Anatomy and Physiology, Kansas State University 1620 Denison Avenue Manhattan Kansas USA +1 785 532 6311
| | - Susumu Ishiguro
- Department of Anatomy and Physiology, Kansas State University 1620 Denison Avenue Manhattan Kansas USA +1 785 532 6311
| | - Masaaki Tamura
- Department of Anatomy and Physiology, Kansas State University 1620 Denison Avenue Manhattan Kansas USA +1 785 532 6311
| | - Jeffrey Comer
- Department of Anatomy and Physiology, Kansas State University 1620 Denison Avenue Manhattan Kansas USA +1 785 532 6311
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3
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Li NZ, Yu CH, Wu JY, Huang SJ, Huang SL, Cheng RP. Diagonal Interactions between Glutamate and Arginine Analogs with Varying Side-Chain Lengths in a β-Hairpin. Molecules 2023; 28:molecules28072888. [PMID: 37049652 PMCID: PMC10096425 DOI: 10.3390/molecules28072888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/14/2023] [Accepted: 03/14/2023] [Indexed: 04/14/2023] Open
Abstract
Cross-strand interactions are important for the stability of β-sheet structures. Accordingly, cross-strand diagonal interactions between glutamate and arginine analogs with varying side-chain lengths were studied in a series of β-hairpin peptides. The peptides were analyzed by homonuclear two-dimensional nuclear magnetic resonance methods. The fraction folded population and folding free energy of the peptides were derived from the chemical shift data. The fraction folded population trends could be rationalized using the strand propensity of the constituting residues, which was not the case for the peptides with lysine analogs, highlighting the difference between the arginine analogs and lysine analogs. Double-mutant cycle analysis was used to derive the diagonal ion-pairing interaction energetics. The most stabilizing diagonal cross-strand interaction was between the shortest residues (i.e., Asp2-Agp9), most likely due to the least side-chain conformational penalty for ion-pair formation. The diagonal interaction energetics in this study involving the arginine analogs appears to be consistent with and extend beyond our understanding of diagonal ion-pairing interactions involving lysine analogs. The results should be useful for designing β-strand-containing molecules to affect biological processes such as amyloid formation and protein-protein interactions.
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Affiliation(s)
- Nian-Zhi Li
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chen-Hsu Yu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Jhuan-Yu Wu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, Taipei 10617, Taiwan
| | - Shou-Ling Huang
- Instrumentation Center, National Taiwan University, Taipei 10617, Taiwan
| | - Richard P Cheng
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
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4
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Legleiter J, Thakkar R, Velásquez-Silva A, Miranda-Carvajal I, Whitaker S, Tomich J, Comer J. Design of Peptides that Fold and Self-Assemble on Graphite. J Chem Inf Model 2022; 62:4066-4082. [PMID: 35881533 PMCID: PMC9472279 DOI: 10.1021/acs.jcim.2c00419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The graphite-water interface provides a unique environment for polypeptides that generally favors ordered structures more than in solution. Therefore, systems consisting of designed peptides and graphitic carbon might serve as a convenient medium for controlled self-assembly of functional materials. Here, we computationally designed cyclic peptides that spontaneously fold into a β-sheet-like conformation at the graphite-water interface and self-assemble, and we subsequently observed evidence of such assembly by atomic force microscopy. Using a novel protocol, we screened nearly 2000 sequences, optimizing for formation of a unique folded conformation while discouraging unfolded or misfolded conformations. A head-to-tail cyclic peptide with the sequence GTGSGTGGPGGGCGTGTGSGPG showed the greatest apparent propensity to fold spontaneously, and this optimized sequence was selected for larger scale molecular dynamics simulations, rigorous free-energy calculations, and experimental validation. In simulations ranging from hundreds of nanoseconds to a few microseconds, we observed spontaneous folding of this peptide at the graphite-water interface under many different conditions, including multiple temperatures (295 and 370 K), with different initial orientations relative to the graphite surface, and using different molecular dynamics force fields (CHARMM and Amber). The thermodynamic stability of the folded conformation on graphite over a range of temperatures was verified by replica-exchange simulations and free-energy calculations. On the other hand, in free solution, the folded conformation was found to be unstable, unfolding in tens of picoseconds. Intermolecular hydrogen bonds promoted self-assembly of the folded peptides into linear arrangements where the peptide backbone exhibited a tendency to align along one of the six zigzag directions of the graphite basal plane. For the optimized peptide, atomic force microscopy revealed growth of single-molecule-thick linear patterns of 6-fold symmetry, consistent with the simulations, while no such patterns were observed for a control peptide with the same amino acid composition but a scrambled sequence.
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Affiliation(s)
- Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Ravindra Thakkar
- Nanotechnology Innovation Center of Kansas State, Institute of Computational Comparative Medicine, Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506-5802, United States
| | - Astrid Velásquez-Silva
- Facultad de Ciencias de la Salud, Programa de Fisioterapia, Corporación Universitaria Iberoamericana, Calle 67 No. 5-27, 110231 Bogotá, Colombia
| | - Ingrid Miranda-Carvajal
- Centro de Innovación y Tecnología - Instituto Colombiano del Petróleo - Ecopetrol S.A., Km 7 vía Bucaramanga, 681011 Piedecuesta, Colombia
| | - Susan Whitaker
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506-5802, United States
| | - John Tomich
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506-5802, United States
| | - Jeffrey Comer
- Nanotechnology Innovation Center of Kansas State, Institute of Computational Comparative Medicine, Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506-5802, United States
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5
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The Effects of Charged Amino Acid Side-Chain Length on Diagonal Cross-Strand Interactions between Carboxylate- and Ammonium-Containing Residues in a β-Hairpin. Molecules 2022; 27:molecules27134172. [PMID: 35807421 PMCID: PMC9268152 DOI: 10.3390/molecules27134172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 02/02/2023] Open
Abstract
The β-sheet is one of the common protein secondary structures, and the aberrant aggregation of β-sheets is implicated in various neurodegenerative diseases. Cross-strand interactions are an important determinant of β-sheet stability. Accordingly, both diagonal and lateral cross-strand interactions have been studied. Surprisingly, diagonal cross-strand ion-pairing interactions have yet to be investigated. Herein, we present a systematic study on the effects of charged amino acid side-chain length on a diagonal ion-pairing interaction between carboxylate- and ammonium-containing residues in a β-hairpin. To this end, 2D-NMR was used to investigate the conformation of the peptides. The fraction folded population and the folding free energy were derived from the chemical shift data. The fraction folded population for these peptides with potential diagonal ion pairs was mostly lower compared to the corresponding peptide with a potential lateral ion pair. The diagonal ion-pairing interaction energy was derived using double mutant cycle analysis. The Asp2-Dab9 (Asp: one methylene; Dab: two methylenes) interaction was the most stabilizing (−0.79 ± 0.14 kcal/mol), most likely representing an optimal balance between the entropic penalty to enable the ion-pairing interaction and the number of side-chain conformations that can accommodate the interaction. These results should be useful for designing β-sheet containing molecular entities for various applications.
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6
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Albanese KI, Leaver-Fay A, Treacy JW, Park R, Houk KN, Kuhlman B, Waters ML. Comparative Analysis of Sulfonium-π, Ammonium-π, and Sulfur-π Interactions and Relevance to SAM-Dependent Methyltransferases. J Am Chem Soc 2022; 144:2535-2545. [PMID: 35108000 PMCID: PMC8923077 DOI: 10.1021/jacs.1c09902] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the measurement and analysis of sulfonium-π, thioether-π, and ammonium-π interactions in a β-hairpin peptide model system, coupled with computational investigation and PDB analysis. These studies indicated that the sulfonium-π interaction is the strongest and that polarizability contributes to the stronger interaction with sulfonium relative to ammonium. Computational studies demonstrate that differences in solvation of the trimethylsulfonium versus the trimethylammonium group also contribute to the stronger sulfonium-π interaction. In comparing sulfonium-π versus sulfur-π interactions in proteins, analysis of SAM- and SAH-bound enzymes in the PDB suggests that aromatic residues are enriched in close proximity to the sulfur of both SAM and SAH, but the populations of aromatic interactions of the two cofactors are not significantly different, with the exception of the Me-π interactions in SAM, which are the most prevalent interaction in SAM but are not possible for SAH. This suggests that the weaker interaction energies due to loss of the cation-π interaction in going from SAM to SAH may contribute to turnover of the cofactor.
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Affiliation(s)
- Katherine I. Albanese
- Department of Chemistry, CB 3290, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599
| | - Andrew Leaver-Fay
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599
| | - Joseph W. Treacy
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, 90095-1569
| | - Rodney Park
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599
| | - K. N. Houk
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, 90095-1569
| | - Brian Kuhlman
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599
| | - Marcey L. Waters
- Department of Chemistry, CB 3290, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599
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7
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Richaud AD, Zhao G, Hobloss S, Roche SP. Folding in Place: Design of β-Strap Motifs to Stabilize the Folding of Hairpins with Long Loops. J Org Chem 2021; 86:13535-13547. [PMID: 34499510 PMCID: PMC8576641 DOI: 10.1021/acs.joc.1c01442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Despite their pivotal role in defining antibody affinity and protein function, β-hairpins harboring long noncanonical loops remain synthetically challenging because of the large entropic penalty associated with their conformational folding. Little is known about the contribution and impact of stabilizing motifs on the folding of β-hairpins with loops of variable length and plasticity. Here, we report a design of minimalist β-straps (strap = strand + cap) that offset the entropic cost of long-loop folding. The judicious positioning of noncovalent interactions (hydrophobic cluster and salt-bridge) within the novel 8-mer β-strap design RW(V/H)W···WVWE stabilizes hairpins with up to 10-residue loops of varying degrees of plasticity (Tm up to 52 °C; 88 ± 1% folded at 18 °C). This "hyper" thermostable β-strap outperforms the previous gold-standard technology of β-strand-β-cap (16-mer) and provides a foundation for producing new classes of long hairpins as a viable and practical alternative to macrocyclic peptides.
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Affiliation(s)
- Alexis D Richaud
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Guangkuan Zhao
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Samir Hobloss
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Stéphane P Roche
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
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8
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Lella M, Mahalakshmi R. De novo
design of metal‐binding cleft in a
Trp‐Trp
stapled thermostable β‐hairpin peptide. Pept Sci (Hoboken) 2021. [DOI: 10.1002/pep2.24240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Muralikrishna Lella
- Molecular Biophysics Laboratory, Department of Biological Sciences Indian Institute of Science Education and Research Bhopal India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences Indian Institute of Science Education and Research Bhopal India
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9
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Swapping the Positions in a Cross-Strand Lateral Ion-Pairing Interaction between Ammonium- and Carboxylate-Containing Residues in a β-Hairpin. Molecules 2021; 26:molecules26051346. [PMID: 33802596 PMCID: PMC7961788 DOI: 10.3390/molecules26051346] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 11/20/2022] Open
Abstract
Cross-strand lateral ion-pairing interactions are important for antiparallel β-sheet stability. Statistical studies suggested that swapping the position of cross-strand lateral residues should not significantly affect the interaction. Herein, we swapped the position of ammonium- and carboxylate-containing residues with different side-chain lengths in a cross-strand lateral ion-pairing interaction in a β-hairpin. The peptides were analyzed by 2D-NMR. The fraction folded population and folding free energy were derived from the chemical shift data. The ion-pairing interaction energy was derived using double mutant cycle analysis. The general trends for the fraction folded population and interaction energetics remained similar upon swapping the position of the interacting charged residues. The most stabilizing cross-strand interactions were between short residues, similar to the unswapped study. However, the fraction folded populations for most of the swapped peptides were higher compared to the corresponding unswapped peptides. Furthermore, subtle differences in the ion-pairing interaction energy upon swapping were observed, most likely due to the “unleveled” relative positioning of the interacting residues created by the inherent right-handed twist of the structure. These results should be useful for developing functional peptides that rely on lateral ion-pairing interactions across antiparallel β-strands.
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10
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Mishra M, Singh V, Tellis MB, Joshi RS, Pandey KC, Singh S. Cyclic peptide engineered from phytocystatin inhibitory hairpin loop as an effective modulator of falcipains and potent antimalarial. J Biomol Struct Dyn 2020; 40:3642-3654. [PMID: 33292080 DOI: 10.1080/07391102.2020.1848629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Cystatins are classical competitive inhibitors of C1 family cysteine proteases (papain family). Phytocystatin superfamily shares high sequence homology and typical tertiary structure with conserved glutamine-valine-glycine (Q-X-V-X-G) loop blocking the active site of C1 proteases. Here, we develop a cysteine-bounded cyclic peptide (CYS-cIHL) and linear peptide (CYS-IHL), using the conserved inhibitory hairpin loop amino acid sequence. Using an in silico approach based on modeling, protein-peptide docking, molecular dynamics simulations and calculation of free energy of binding, we designed and validated inhibitory peptides against falcipain-2 (FP-2) and -3 (FP-3), cysteine proteases from the malarial parasite Plasmodium falciparum. Falcipains are critical hemoglobinases of P. falciparum that are validated targets for the development of antimalarial therapies. CYS-cIHL was able to bind with micromolar affinity to FP-2 and modulate its binding with its substrate, hemoglobin in in vitro and in vivo assays. CYS-cIHL could effectively block parasite growth and displayed antimalarial activity in culture assays with no cytotoxicity towards human cells. These results indicated that cyclization can substantially increase the peptide affinity to the target. Furthermore, this can be applied as an effective strategy for engineering peptide inhibitory potency against proteases.
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Affiliation(s)
- Manasi Mishra
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Uttar Pradesh, India
| | - Vigyasa Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Meenakshi B Tellis
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
| | - Rakesh S Joshi
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Kailash C Pandey
- Parasite-Host Biology Group, ICMR National Institute of Malaria Research, Dwarka, India
| | - Shailja Singh
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Uttar Pradesh, India.,Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
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11
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Rayevsky A, Platonov M, Hurmach V, Yakovenko A, Volochnyuk D. Peptidyl inhibition of Spt4-Spt5: Protein-protein inhibitors for targeting the transcriptional pathway related to C9orf72 expansion repeats. J Cell Biochem 2020; 121:4922-4930. [PMID: 32628322 DOI: 10.1002/jcb.29820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 05/15/2020] [Accepted: 06/12/2020] [Indexed: 11/09/2022]
Abstract
Spt4/Spt5 is an useful target as it is likely a transcription factor that has implications for long non-coding RNA repeats related to frontotemporal dementia (FTD) found in the C9orf72 disease pathology. Inhibitors for Spt4/Spt5 using peptides as a starting point for assays as a means for developing small molecules, which could likely lead to therapeutic development for inhibition for Spt4/Spt5 with CNS characteristics. To elucidate the specific steps of identification and modification of key interacting residues from Spt4/Spt5 complex with further effect prediction, a set of different computational methods was applied. Newly characterized, theoretically derived peptides docked on Spt4/Spt5 models, based on X-ray crystallography sources, allowed us to complete molecular dynamics simulations and docking studies for peptide libraries that give us high confident set of peptides for use to screen for Spt4/Spt5 inhibition. Several peptides with increased specificity to the Spt4/Spt5 interface were found and can be screened in cell-based assays and enzymatic assays for peptide screens that lead to small molecule campaigns. Spt4/Spt5 comprises an attractive target for neurological diseases, and applying these peptides into a screening campaign will promote the goal of therapeutic searches for FTD drug discovery.
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12
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Horx P, Geyer A. Defining the mobility range of a hinge-type connection using molecular dynamics and metadynamics. PLoS One 2020; 15:e0230962. [PMID: 32282813 PMCID: PMC7153902 DOI: 10.1371/journal.pone.0230962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 03/12/2020] [Indexed: 01/29/2023] Open
Abstract
A designed disulfide-rich β-hairpin peptide that dimerizes spontaneously served as a hinge-type connection between proteins. Here, we analyze the range of dynamics of this hinge dimer with the aim of proposing new applications for the DNA-encodable peptide and establishing guidelines for the computational analysis of other disulfide hinges. A recent structural analysis based on nuclear magnetic resonance spectroscopy and ion mobility spectrometry revealed an averaged conformation in the hinge region which motivated us to investigate the dynamic behavior using a combination of molecular dynamics simulation, metadynamics and free energy surface analysis to characterize the conformational space available to the hinge. Principal component analysis uncovered two slow modes of the peptide, namely, the opening and closing motion and twisting of the two β-hairpins assembling the hinge. Applying a collective variable (CV) that mimics the first dominating mode, led to a major expansion of the conformational space. The description of the dynamics could be achieved by analysis of the opening angle and the twisting of the β-hairpins and, thus, offers a methodology that can also be transferred to other derivatives. It has been demonstrated that the hinge peptide’s lowest energy conformation consists of a large opening angle and strong twist but is separated by small energy barriers and can, thus, adopt a closed and untwisted structure. With the aim of proposing further applications for the hinge peptide, we simulated its behavior in the sterically congested environment of a four-helix bundle. Preliminary investigations show that one helix is pushed out and a three-helix bundle forms. The insights gained into the dynamics of the tetra-disulfide peptide and analytical guidelines developed in this study may contribute to the understanding of the structure and function of more complex hinge-type proteins, such as the IgG antibody family.
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Affiliation(s)
- Philip Horx
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
| | - Armin Geyer
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
- * E-mail:
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13
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Design and structural characterisation of monomeric water-soluble α-helix and β-hairpin peptides: State-of-the-art. Arch Biochem Biophys 2019; 661:149-167. [DOI: 10.1016/j.abb.2018.11.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/06/2018] [Accepted: 11/14/2018] [Indexed: 02/06/2023]
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14
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Schrimpf A, Brödje D, Pfefferle P, Geyer A. A set of conformationally well-defined L/D-peptide epitopes provides a serological bar code for autoantibody subtypes. PLoS One 2018; 13:e0201735. [PMID: 30075018 PMCID: PMC6075753 DOI: 10.1371/journal.pone.0201735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/21/2018] [Indexed: 11/23/2022] Open
Abstract
Which conformational parameters lead to an antibody-affine peptide antigen? And in how many different conformations can we actually present the respective conformational epitope? To provide answers from a chemical point of view, we direct the bending and tethering of peptide backbones by the utilisation of a hydrophobic cluster, disulfides, and d-amino acids. Each mutation is employed pairwise on directly opposite sides of a β-hairpin. In combination, these synthetic modules guide the formation of complementary β-sheet-like structures, whereby the oppositely configured (l/d-)bi-disulfide pairs form with high regioselectivity. The conformational properties of the peptides are assessed by NMR spectroscopy and correlated with their antibody affinity in ELISA. From a pool of thus designed peptide antigens with distinctive complementary affinities against known rheumatoid arthritis (RA) autoantibodies, we select a set of epitopes for an immunoassay with sera of RA patients. We want to put emphasis on the idea, that the different conformational properties of the chosen antigens, containing the same epitope sequence, are mirrored in the distribution of autoantibody subtypes (or of the antibody polyclonality, respectively). Such directly comparable information can only be delivered by a set of peptides, rather than a single one. The hairpin-restriction technology of l/d-configured bi-disulfide amino acid pairs is not limited to RA but applicable to other shape-persistent hairpin motifs which are supposed to identify subgroups of protein receptors.
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Affiliation(s)
- Andreas Schrimpf
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
| | - Dörte Brödje
- Department of Medicine, Philipps-Universität Marburg, Marburg, Germany
| | - Petra Pfefferle
- Comprehensive Biomaterial Bank Marburg (CBBMR), Marburg, Germany
| | - Armin Geyer
- Department of Chemistry, Philipps-Universität Marburg, Marburg, Germany
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15
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Shi YD, Tang Q, Jiang YF, Pei Q, Tan HW, Lu ZL, Gong B. Effective formation of stable and versatile double-stranded β-sheets templated by a hydrogen-bonded duplex. Chem Commun (Camb) 2018; 54:3719-3722. [DOI: 10.1039/c8cc01564c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
An effective approach to construct stable and versatile double-stranded β-sheets composed of tetra- and penta-peptides through a hydrogen-bonded duplex template has been explored.
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Affiliation(s)
- You-Di Shi
- Key Laboratory of Radiopharmaceuticals
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Quan Tang
- Key Laboratory of Radiopharmaceuticals
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Ya-Fei Jiang
- Key Laboratory of Radiopharmaceuticals
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Qiang Pei
- Key Laboratory of Radiopharmaceuticals
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Hong-Wei Tan
- Key Laboratory of Radiopharmaceuticals
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Zhong-Lin Lu
- Key Laboratory of Radiopharmaceuticals
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
| | - Bing Gong
- Key Laboratory of Radiopharmaceuticals
- Ministry of Education
- College of Chemistry
- Beijing Normal University
- Beijing 100875
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16
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Wang L, Xing D, Le Van A, Jerse AE, Wang S. Structure-based design of ferritin nanoparticle immunogens displaying antigenic loops of Neisseria gonorrhoeae. FEBS Open Bio 2017; 7:1196-1207. [PMID: 28781959 PMCID: PMC5537070 DOI: 10.1002/2211-5463.12267] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/12/2017] [Accepted: 06/13/2017] [Indexed: 11/09/2022] Open
Abstract
Effective vaccines are urgently needed to combat gonorrhea, a common sexually transmitted bacterial infection, for which treatment options are diminishing due to rapid emergence of antibiotic resistance. We have used a rational approach to the development of gonorrhea vaccines, and genetically engineered nanoparticles to present antigenic peptides of Neisseria gonorrhoeae, the causative agent of gonorrhea. We hypothesized that the ferritin nanocage could be used as a platform to display an ordered array of N. gonorrhoeae antigenic peptides on its surface. MtrE, the outer membrane channel of the highly conserved gonococcal MtrCDE active efflux pump, is an attractive vaccine target due to its importance in protecting N. gonorrhoeae from host innate effectors and antibiotic resistance. Using computational approaches, we designed constructs that expressed chimeric proteins of the Helicobacter pylori ferritin and antigenic peptides that correspond to the two surface-exposed loops of N. gonorrhoeae MtrE. The peptides were inserted at the N terminus or in a surface-exposed ferritin loop between helices αA and αB. Crystal structures of the chimeric proteins revealed that the proteins assembled correctly into a 24-mer nanocage structure. Although the inserted N. gonorrhoeae peptides were disordered, it was clear that they were displayed on the nanocage surface, but with multiple conformations. Our results confirmed that the ferritin nanoparticle is a robust platform to present antigenic peptides and therefore an ideal system for rational design of immunogens.
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Affiliation(s)
- Liqin Wang
- Department of Biochemistry and Molecular Biology Uniformed Services University of the Health Sciences Bethesda MD USA
| | - Daniel Xing
- Department of Biochemistry and Molecular Biology Uniformed Services University of the Health Sciences Bethesda MD USA
| | - Adriana Le Van
- Department of Microbiology and Immunology Uniformed Services University of the Health Sciences Bethesda MD USA
| | - Ann E Jerse
- Department of Microbiology and Immunology Uniformed Services University of the Health Sciences Bethesda MD USA
| | - Shuishu Wang
- Department of Biochemistry and Molecular Biology Uniformed Services University of the Health Sciences Bethesda MD USA
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17
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Reutzel J, Diogo TM, Geyer A. Reversible Folding of a β-Hairpin Peptide by a Metal-Chelating Amino Acid. Chemistry 2017; 23:8450-8456. [DOI: 10.1002/chem.201700698] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Jan Reutzel
- Department of Chemistry; Philipps-University Marburg; Hans-Meerwein-Str. 4 35032 Marburg Germany
| | - Timm M. Diogo
- Department of Chemistry; Philipps-University Marburg; Hans-Meerwein-Str. 4 35032 Marburg Germany
| | - Armin Geyer
- Department of Chemistry; Philipps-University Marburg; Hans-Meerwein-Str. 4 35032 Marburg Germany
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18
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Schrimpf A, Linne U, Geyer A. Eight at one stroke – a synthetic tetra-disulfide peptide epitope. Org Biomol Chem 2017; 15:2512-2521. [DOI: 10.1039/c6ob02746f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A tetra-disulfide peptide dimer, representing an antiparallel hinge, is synthesised without the need for orthogonal cysteine protecting groups.
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Affiliation(s)
- Andreas Schrimpf
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Uwe Linne
- Mass spectrometry facility of the Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
| | - Armin Geyer
- Department of Chemistry
- Philipps-Universität Marburg
- 35032 Marburg
- Germany
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19
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Schrimpf A, Geyer A. Two Opposing d-Amino Acids Give Zigzag Hairpin Epitopes an Additional Kink to Create Antibody-Selective Peptide Antigens. Chembiochem 2016; 17:2129-2132. [PMID: 27595488 DOI: 10.1002/cbic.201600479] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Indexed: 12/17/2022]
Abstract
We have developed peptides that are able to distinguish between subgroups of polyclonal antibodies. These β-hairpin peptides act as conformational epitopes with specific shape and flexibility; they have been analyzed by NMR and CD spectroscopy, and have been shown to identify known disease markers. As a standalone mini β-sheet, a hairpin is stabilized by alternating pairs of hydrogen-bonded and non-bonded amino acids on its two opposing peptide strands. A single d mutation disrupts this secondary structure, the correlated double-d mutation of two opposing amino acids compensates for this destabilizing effect. The designed kink was introduced into both hydrogen-bonded and -non-bonded positions of an all-l hairpin that is a known conformational epitope in molecular recognition. Our peptides enabled the discrimination of different human rheumatoid arthritis autoantibodies in an ELISA assay.
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Affiliation(s)
- Andreas Schrimpf
- Faculty of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straßsse 4, 35032, Marburg, Germany
| | - Armin Geyer
- Faculty of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straßsse 4, 35032, Marburg, Germany
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20
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Fischer S, Lamping M, Gold M, Röttger Y, Brödje D, Dodel R, Frantz R, Mraheil MA, Chakraborty T, Geyer A. Synthesis of a biological active β-hairpin peptide by addition of two structural motifs. Bioorg Med Chem 2016; 25:603-608. [PMID: 27887962 DOI: 10.1016/j.bmc.2016.11.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/09/2016] [Accepted: 11/13/2016] [Indexed: 12/18/2022]
Abstract
The idea of privileged scaffolds - that there seem to be more bioactive compounds found around some structures than others - is well established for small drug molecules, but has little significance for standalone peptide secondary structures whose adaptable shapes escape the definition of a 3D motif in the absence of a protein scaffold. Here, we joined two independent biological functions in a single highly restricted peptide to support the hypothesis that the β-hairpin shape is the common basis of two otherwise unrelated biological recognition processes. To achieve this, the hydrophobic cluster HWX4LV from the decapeptide cyclic hairpin model peptide C1-C10cyclo-CHWEGNKLVC was included in the bicyclic peptide 2. The designed β-hairpin peptide C4-C17, C8-C13bicyclo-KHQCHWECTZGRCRLVCGRSGS (2, Z=citrulline), serves, on the one hand, as a specific epitope for rheumatoid autoantibodies and, on the other hand, shows a not negligible antibiotic effect against the bacterial strain E. coli AS19.
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Affiliation(s)
- Sabrina Fischer
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Matthias Lamping
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Maike Gold
- Department of Neurology, Philipps-University Marburg, Baldingerstraße, 35043 Marburg, Germany
| | - Yvonne Röttger
- Department of Neurology, Philipps-University Marburg, Baldingerstraße, 35043 Marburg, Germany
| | - Dörte Brödje
- Institute for Medical Microbiology and Hospital Hygiene, University Hospital Giessen and Marburg, Hans-Meerwein-Straße, 35033 Marburg, Germany
| | - Richard Dodel
- Department of Neurology, Philipps-University Marburg, Baldingerstraße, 35043 Marburg, Germany
| | - Renate Frantz
- Institute for Medical Microbiology, Justus-Liebig University, Biomedical Research Facility Seltersberg, Schubertstraße 81, 35392 Giessen, Germany
| | - Mobarak Abu Mraheil
- Institute for Medical Microbiology, Justus-Liebig University, Biomedical Research Facility Seltersberg, Schubertstraße 81, 35392 Giessen, Germany
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Biomedical Research Facility Seltersberg, Schubertstraße 81, 35392 Giessen, Germany
| | - Armin Geyer
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
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21
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Stewart AL, Lorts AR, Seal EL, Takas NJ, Fortenberry RC. The role of sodium ions in the solubility of peptides. Struct Chem 2016. [DOI: 10.1007/s11224-016-0825-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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22
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Xu Z, Luo HH, Tieleman DP. Modifying the OPLS-AA force field to improve hydration free energies for several amino acid side chains using new atomic charges and an off-plane charge model for aromatic residues. J Comput Chem 2016; 28:689-97. [PMID: 17195160 DOI: 10.1002/jcc.20560] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The hydration free energies of amino acid side chains are an important determinant of processes that involve partitioning between different environments, including protein folding, protein complex formation, and protein-membrane interactions. Several recent papers have shown that calculated hydration free energies for polar and aromatic residues (Trp, His, Tyr, Asn, Gln, Asp, Glu) in several common molecular dynamics force fields differ significantly from experimentally measured values. We have attempted to improve the hydration energies for these residues by modifying the partial charges of the OPLS-AA force field based on natural population analysis of density functional theory calculations. The resulting differences between calculated hydration free energies and experimental results for the seven side chain analogs are less than 0.1 kcal/mol. Simulations of the synthetic Trp-rich peptide Trpzip2 show that the new charges lead to significantly improved geometries for interacting Trp-side chains. We also investigated an off-plane charge model for aromatic rings that more closely mimics their electronic configuration. This model results in an improved free energy of hydration for Trp and a somewhat altered benzene-sodium potential of mean force with a more favorable energy for direct benzene-sodium contact.
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Affiliation(s)
- Zhitao Xu
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
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23
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Kier BL, Anderson JM, Andersen NH. Disulfide-Mediated β-Strand Dimers: Hyperstable β-Sheets Lacking Tertiary Interactions and Turns. J Am Chem Soc 2015; 137:5363-71. [PMID: 25835058 PMCID: PMC7450586 DOI: 10.1021/ja5117809] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Disulfide bonds between cysteine residues are essential to the structure and folding of many proteins. Yet their role in the design of structured peptides and proteins has frequently been limited to use as intrachain covalent staples that reinforce existing structure or induce knot-like conformations. In β-hairpins, their placement at non-H-bonding positions across antiparallel strands has proven useful for achieving fully folded positive controls. Here we report a new class of designed β-sheet peptide dimers with strand-central disulfides as a key element. We have found that the mere presence of a disulfide bond near the middle of a short peptide chain is sufficient to nucleate some antiparallel β-sheet structure; addition of β-capping units and other favorable cross-strand interactions yield hyperstable sheets. Strand-central cystines were found to be superior to the best designed reversing turns in terms of nucleating β-sheet structure formation. We have explored the limitations and possibilities of this technique (the use of disulfides as sheet nucleators), and we provide a set of rules and rationales for the application and further design of disulfide-tethered "turnless" β-sheets.
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Affiliation(s)
- Brandon L Kier
- Chemistry Department, University of Washington, Seattle, Washington 98195, United States
| | - Jordan M Anderson
- Chemistry Department, University of Washington, Seattle, Washington 98195, United States
| | - Niels H Andersen
- Chemistry Department, University of Washington, Seattle, Washington 98195, United States
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24
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Körling M, Geyer A. Stabilization of a Natural β-Hairpin by a Twist-Compatible β-Turn Mimetic. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500048] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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25
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Kuo HT, Liu SL, Chiu WC, Fang CJ, Chang HC, Wang WR, Yang PA, Li JH, Huang SJ, Huang SL, Cheng RP. Effect of charged amino acid side chain length on lateral cross-strand interactions between carboxylate- and guanidinium-containing residues in a β-hairpin. Amino Acids 2015; 47:885-98. [PMID: 25646959 DOI: 10.1007/s00726-015-1916-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Accepted: 01/06/2015] [Indexed: 10/24/2022]
Abstract
β-Sheet is one of the major protein secondary structures. Oppositely charged residues are frequently observed across neighboring strands in antiparallel sheets, suggesting the importance of cross-strand ion pairing interactions. The charged amino acids Asp, Glu, Arg, and Lys have different numbers of hydrophobic methylenes linking the charged functionality to the backbone. To investigate the effect of side chain length of guanidinium- and carboxylate-containing residues on lateral cross-strand ion pairing interactions at non-hydrogen-bonded positions, β-hairpin peptides containing Zbb-Agx (Zbb = Asp, Glu, Aad in increasing length; Agx = Agh, Arg, Agb, Agp in decreasing length) sequence patterns were studied by NMR methods. The fraction folded population and folding energy were derived from the chemical shift deviation data. Peptides with high fraction folded populations involved charged residue side chain lengths that supported high strand propensity. Double mutant cycle analysis was used to determine the interaction energy for the potential lateral ion pairs. Minimal interaction was observed between residues with short side chains, most likely due to the diffused positive charge on the guanidinium group, which weakened cross-strand electrostatic interactions with the carboxylate side chain. Only the Aad-Arg/Agh interactions with long side chains clearly exhibited stabilizing energetics, possibly relying on hydrophobics. A survey of a non-redundant protein structure database revealed that the statistical sheet pair propensity followed the trend Asp-Arg < Glu-Arg, implying the need for matching long side chains. This suggested the need for long side chains on both guanidinium-bearing and carboxylate-bearing residues to stabilize the β-hairpin motif.
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Affiliation(s)
- Hsiou-Ting Kuo
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
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26
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Markiewicz BN, Culik RM, Gai F. Tightening up the structure, lighting up the pathway: Application of molecular constraints and light to manipulate protein folding, self-assembly and function. Sci China Chem 2014; 57:1615-1624. [PMID: 25722715 PMCID: PMC4337807 DOI: 10.1007/s11426-014-5225-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Chemical cross-linking provides an effective avenue to reduce the conformational entropy of polypeptide chains and hence has become a popular method to induce or force structural formation in peptides and proteins. Recently, other types of molecular constraints, especially photoresponsive linkers and functional groups, have also found increased use in a wide variety of applications. Herein, we provide a concise review of using various forms of molecular strategies to constrain proteins, thereby stabilizing their native states, gaining insight into their folding mechanisms, and/or providing a handle to trigger a conformational process of interest with light. The applications discussed here cover a wide range of topics, ranging from delineating the details of the protein folding energy landscape to controlling protein assembly and function.
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Affiliation(s)
| | - Robert M. Culik
- Department of Biochemistry and Biophysics, University of Pennsylvania, PA, 19104, USA
| | - Feng Gai
- Department of Chemistry, University of Pennsylvania, PA, 19104, USA
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27
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Makwana KM, Mahalakshmi R. Asymmetric contribution of aromatic interactions stems from spatial positioning of the interacting aryl pairs in β-hairpins. Chembiochem 2014; 15:2357-60. [PMID: 25196944 DOI: 10.1002/cbic.201402340] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Indexed: 11/11/2022]
Abstract
Isolated aromatic interactions in designed octapeptide β-hairpin scaffolds display a near-universal T-shaped face-to-edge geometry in all positional permutations, with the exception of aryl-Trp interactions. The heterogeneous asymmetric indole ring of Trp competes for a "shielding" face geometry, which lowers the scaffold stability in FtE aryl-Trp pairs. Assessment of the contributions of aryl pairs (in the absence of solvent-driven interactions) to the overall β-hairpin structure reveals the superiority of Trp-Phe and Trp-Tyr contributions over the well-established scaffold stabilization by Trp-Trp.
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Affiliation(s)
- Kamlesh Madhusudan Makwana
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh 462023 (India)
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28
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Rouch DA. Evolution of the first genetic cells and the universal genetic code: a hypothesis based on macromolecular coevolution of RNA and proteins. J Theor Biol 2014; 357:220-44. [PMID: 24931677 DOI: 10.1016/j.jtbi.2014.06.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 06/02/2014] [Accepted: 06/03/2014] [Indexed: 11/19/2022]
Abstract
A qualitative hypothesis based on coevolution of protein and nucleic acid macromolecules was developed to explain the evolution of the first genetic cells, from the likely organic chemical-rich environment of early earth, through to the Last Universal Common Ancestor (LUCA). The evolution of the first genetic cell was divided into three phases, proto-genetic cells I, II and III, and the transition to each milestone is described, based on development of chemical cross-catalysis, bio-cross-catalysis, and the universal genetic code, respectively. Selection of macromolecular properties of both peptides and nucleic acids, in response to environmental factors, was likely to be a key aspect of early evolution. The development of hereditable nucleic acids with various key functions; translation, transcription and replication, is described. These functions are envisaged to have coevolved with protein enzymes, from simple organic precursors. Genetically heritable nucleotides may have developed after the local earth environment had cooled below 63 °C. Around this temperature G-C bases would have been preferentially utilized for nucleotide synthesis. Under these conditions RNA type nucleotides were then likely selected from a range of different types of nucleotide backbones through template-based synthesis. Initial development of the genetic coding system was simplified by the availability of proto-messenger RNA sequences that contained only G and C bases, and the need to encode only four amino acids. The step-wise addition of further amino acids to the code was predicted to parallel the growing metabolic complexity of the proto-genetic cell. On completion of this evolutionary process the proto-genetic cell is envisaged to have become the LUCA, the last common ancestor of bacteria, eukaryote and archaea domains. Key issues addressed by the model include: (a) the transition from non-hereditable random sequences of peptides and nucleic acids to specific proteins coded by hereditable nucleotide sequences, (b) the origin of homochiral amino acids and sugars, and (c) the mutation limits on the sizes of early nucleic acid genomes. The first genome was limited to a size of about 200 base pairs.
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Affiliation(s)
- Duncan A Rouch
- Biotechnology and Environmental Biology, RMIT University, PO Box 71, Bundoora, Melbourne, Vic 3083, Australia.
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29
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Razavi AM, Wuest WM, Voelz VA. Computational screening and selection of cyclic peptide hairpin mimetics by molecular simulation and kinetic network models. J Chem Inf Model 2014; 54:1425-32. [PMID: 24754484 DOI: 10.1021/ci500102y] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Designing peptidomimetic compounds to have a preorganized structure in solution is highly nontrivial. To show how simulation-based approaches can help speed this process, we performed an extensive simulation study of designed cyclic peptide mimics of a β-hairpin from bacterial protein LapD involved in a protein-protein interaction (PPI) pertinent to bacterial biofilm formation. We used replica exchange molecular dynamics (REMD) simulation to screen 20 covalently cross-linked designs with varying stereochemistry and selected the most favorable of these for massively parallel simulation on Folding@home in explicit solvent. Markov state models (MSMs) built from the trajectory data reveal how subtle chemical modifications can have a significant effect on conformational populations, leading to the overall stabilization of the target structure. In particular, we identify a key steric interaction between a methyl substituent and a valine side chain that acts to allosterically shift population between native and near-native states, which could be exploited in future designs. Visualization of this mechanism is aided considerably by the tICA method, which identifies degrees of freedom most important in slow conformational transitions. The combination of quantitative detail and human comprehension provided by MSMs suggests such approaches will be increasingly useful for design.
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Affiliation(s)
- Asghar M Razavi
- Department of Chemistry, Temple University , Philadelphia, Pennsylvania 19122, United States
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30
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Markiewicz BN, Yang L, Culik RM, Gao YQ, Gai F. How quickly can a β-hairpin fold from its transition state? J Phys Chem B 2014; 118:3317-25. [PMID: 24611730 PMCID: PMC3969101 DOI: 10.1021/jp500774q] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
![]()
Understanding the structural nature
of the free energy bottleneck(s)
encountered in protein folding is essential to elucidating the underlying
dynamics and mechanism. For this reason, several techniques, including
Φ-value analysis, have previously been developed to infer the
structural characteristics of such high free-energy or transition
states. Herein we propose that one (or few) appropriately placed backbone
and/or side chain cross-linkers, such as disulfides, could be used
to populate a thermodynamically accessible conformational state that
mimics the folding transition state. Specifically, we test this hypothesis
on a model β-hairpin, Trpzip4, as its folding mechanism has
been extensively studied and is well understood. Our results show
that cross-linking the two β-strands near the turn region increases
the folding rate by an order of magnitude, to about (500 ns)−1, whereas cross-linking the termini results in a hyperstable β-hairpin
that has essentially the same folding rate as the uncross-linked peptide.
Taken together, these findings suggest that cross-linking is not only
a useful strategy to manipulate folding free energy barriers, as shown
in other studies, but also, in some cases, it can be used to stabilize
a folding transition state analogue and allow for direct assessment
of the folding process on the downhill side of the free energy barrier.
The calculated free energy landscape of the cross-linked Trpzip4 also
supports this picture. An empirical analysis further suggests, when
folding of β-hairpins does not involve a significant free energy
barrier, the folding time (τ) follows a power law dependence
on the number of hydrogen bonds to be formed (nH), namely, τ = τ0nHα, with
τ0 = 20 ns and α = 2.3.
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Affiliation(s)
- Beatrice N Markiewicz
- Department of Chemistry and ‡Department of Biochemistry and Biophysics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
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31
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Fischer S, Geyer A. Filaggrin Peptides with β-Hairpin Structure Bind Rheumatoid Arthritis Antibodies. Angew Chem Int Ed Engl 2014; 53:3849-53. [DOI: 10.1002/anie.201309873] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/15/2014] [Indexed: 11/11/2022]
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32
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Fischer S, Geyer A. Filaggrin-Peptide mit β-Haarnadel-Struktur binden Rheuma-Antikörper. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309873] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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33
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Makwana KM, Mahalakshmi R. Comparative analysis of cross strand aromatic–Phe interactions in designed peptide β-hairpins. Org Biomol Chem 2014; 12:2053-61. [DOI: 10.1039/c3ob42247j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Examination of the preferential interaction geometries of the aromatic amino acids Phe, Tyr and Trp with the benzyl ring of Phe in designed octapeptide hairpin scaffolds reveals stabilizing contributions of a Trp–Phe pair, even in amphipathic solvents.
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Affiliation(s)
- Kamlesh Madhusudan Makwana
- Molecular Biophysics Laboratory
- Department of Biological Sciences
- Indian Institute of Science Education and Research
- Bhopal, India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory
- Department of Biological Sciences
- Indian Institute of Science Education and Research
- Bhopal, India
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34
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Abstract
Since the first report in 1993 (JACS 115, 5887-5888) of a peptide able to form a monomeric β-hairpin structure in aqueous solution, the design of peptides forming either β-hairpins (two-stranded antiparallel β-sheets) or three-stranded antiparallel β-sheets has become a field of growing interest and activity. These studies have yielded great insights into the principles governing the stability and folding of β-hairpins and antiparallel β-sheets. This chapter provides an overview of the reported β-hairpin/β-sheet peptides focussed on the applied design criteria, reviews briefly the factors contributing to β-hairpin/β-sheet stability, and describes a protocol for the de novo design of β-sheet-forming peptides based on them. Guidelines to select appropriate turn and strand residues and to avoid self-association are provided. The methods employed to check the success of new designed peptides are also summarized. Since NMR is the best technique to that end, NOEs and chemical shifts characteristic of β-hairpins and three-stranded antiparallel β-sheets are given.
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Affiliation(s)
- M Angeles Jiménez
- Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Química Física Rocasolano (IQFR), Serrano 119, 28006, Madrid, Spain,
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35
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Kuo HT, Fang CJ, Tsai HY, Yang MF, Chang HC, Liu SL, Kuo LH, Wang WR, Yang PA, Huang SJ, Huang SL, Cheng RP. Effect of charged amino acid side chain length on lateral cross-strand interactions between carboxylate-containing residues and lysine analogues in a β-hairpin. Biochemistry 2013; 52:9212-22. [PMID: 24328126 DOI: 10.1021/bi400974x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
β-Sheets are one of the fundamental three-dimensional building blocks for protein structures. Oppositely charged amino acids are frequently observed directly across one another in antiparallel sheet structures, suggesting the importance of cross-strand ion pairing interactions. Despite the apparent electrostatic nature of ion pairing interactions, the charged amino acids Asp, Glu, Arg, Lys have different numbers of hydrophobic methylenes linking the charged functionality to the backbone. Accordingly, the effect of charged amino acid side chain length on cross-strand ion pairing interactions at lateral non-hydrogen bonded positions was investigated in a β-hairpin motif. The negatively charged residues with a carboxylate (Asp, Glu, Aad in increasing length) were incorporated at position 4, and the positively charged residues with an ammonium (Dap, Dab, Orn, Lys in increasing length) were incorporated at position 9. The fraction folded population and folding free energy were derived from the chemical shift deviation data. Double mutant cycle analysis was used to determine the interaction energy for the potential lateral ion pairs. Only the Asp/Glu-Dap interactions with shorter side chains and the Aad-Orn/Lys interactions with longer side chains exhibited stabilizing energetics, mostly relying on electrostatics and hydrophobics, respectively. This suggested the need for length matching of the interacting residues to stabilize the β-hairpin motif. A survey of a nonredundant protein structure database revealed that the statistical sheet pair propensity followed the trend Asp-Lys < Glu-Lys, also implying the need for length matching of the oppositely charged residues.
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Affiliation(s)
- Hsiou-Ting Kuo
- Department of Chemistry, National Taiwan University , Taipei 10617, Taiwan
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36
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β-Hairpin protein epitope mimetic technology in drug discovery. DRUG DISCOVERY TODAY. TECHNOLOGIES 2013; 9:e1-e70. [PMID: 24064246 DOI: 10.1016/j.ddtec.2011.07.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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37
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Kuo LH, Li JH, Kuo HT, Hung CY, Tsai HY, Chiu WC, Wu CH, Wang WR, Yang PA, Yao YC, Wong TW, Huang SJ, Huang SL, Cheng RP. Effect of charged amino acid side chain length at non-hydrogen bonded strand positions on β-hairpin stability. Biochemistry 2013; 52:7785-97. [PMID: 24156236 DOI: 10.1021/bi400911p] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
β-Sheets have been implicated in various neurological disorders, and ∼20% of protein residues adopt a sheet conformation. Therefore, studies on the structural origin of sheet stability can provide fundamental knowledge with potential biomedical applications. Oppositely charged amino acids are frequently observed across one another in antiparallel β-sheets. Interestingly, the side chains of natural charged amino acids Asp, Glu, Arg, Lys have different numbers of hydrophobic methylenes linking the backbone to the hydrophilic charged functionalities. To explore the inherent effect of charged amino acid side chain length on antiparallel sheets, the stability of a designed hairpin motif containing charged amino acids with varying side chain lengths at non-hydrogen bonded positions was studied. Peptides with the guest position on the N-terminal strand and the C-terminal strand were investigated by NMR methods. The charged amino acids (Xaa) included negatively charged residues with a carboxylate group (Asp, Glu, Aad in increasing length), positively charged residues with an ammonium group (Dap, Dab, Orn, Lys in increasing length), and positively charged residues with a guanidinium group (Agp, Agb, Arg, Agh in increasing length). The fraction folded and folding free energy for each peptide were derived from the chemical shift deviation data. The stability of the peptides with the charged residues at the N-terminal guest position followed the trends: Asp > Glu > Aad, Dap < Dab < Orn ∼ Lys, and Agb < Arg < Agh < Agp. The stability of the peptides with the charged residues at the C-terminal guest position followed the trends: Asp < Glu < Aad, Dap ∼ Dab < Orn ∼ Lys, and Agb < Arg ∼ Agp < Agh. These trends were rationalized by thermodynamic sheet propensity and cross-strand interactions.
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Affiliation(s)
- Li-Hung Kuo
- Department of Chemistry, National Taiwan University , Taipei 10617, Taiwan
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38
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Chitranshi N, Tiwari AK, Somvanshi P, Tripathi PK, Seth PK. Investigating the function of single nucleotide polymorphisms in the CTSB gene: a computational approach. FUTURE NEUROLOGY 2013. [DOI: 10.2217/fnl.13.26] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aim: Recent genome-wide association studies have revealed large numbers of single nucleotide polymorphisms (SNPs) related to Alzheimer’s disease. Here, we have investigated the gene CTSB, which plays a crucial role in encoding CTSB, a lysosomal cysteine proteinase protein. CTSB is also involved in the proteolytic processing of amyloid precursor protein (APP), which is believed to be a causative factor in Alzheimer’s disease. Materials & methods: Several bioinformatics algorithms such as, Sorting Intolerant from Tolerant (SIFT), Polymorphism Phenotyping (PolyPhen) and CUPSAT could identify the synonymous SNPs and nonsynonymous SNPs (nsSNPs), which are predicted to be deleterious and nondeleterious, respectively. Similar tools were used to predict the impact of single amino acid substitutions on CTSB protein activity. The FASTSNP server and UTRscan were used to predict the influence on splicing regulations. The stability and solvent-accessible surface area of modeled mutated proteins were analyzed using PBEQ solver and NetASA view. Furthermore, the DSP program was used to determine the secondary structures of the modeled protein. Results: A total of 999 SNPs in CTSB were retrieved from the SNP database; 55 nsSNPs, 35 synonymous SNPs, 165 mRNA were found in the 3´untranslated region SNPs, 12 SNPs were found in the 5´untranslated region in addition to 732 intronic SNPs. Potential functions of SNPs in the CTSB gene were identified using different web servers. For example, SIFT, PolyPhen and CUPSAT servers predicted ten nsSNPs to be intolerant, three nsSNPs to be damaging and eight nsSNPs to have the potential to destabilize protein structure. The FASTSNP server predicted 12 SNPs to influence splicing regulation, whereas two SNPs could predict a risk in the range of 3–4 (medium to high). Furthermore, mutant proteins were modeled and the total energy values were compared with the native CTSB protein. It was observed that on the surface of the protein, a mutation from threonine to serine at position 235 (rs17573) caused the greatest impact on stability. Conclusion: The genome-wide association studies database has already found rs7003814 of the CTSB gene reported against Alzheimer’s disease. Our study demonstrates the presence of other deleterious nsSNPs, which may play a crucial role in predicting Alzheimer’s disease risk.
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Affiliation(s)
- Nitin Chitranshi
- Gautam Buddh Technical University, Lucknow 227202, Uttar Pradesh, India
- Bioinformatics Centre, Biotech Park, Sector-G, Jankipuram, Lucknow-226021, Uttar Pradesh, India.
| | - Amit K Tiwari
- Department of Biomedical Sciences, College of Veterinary Medicine, Nursing & Allied Health, Tuskegee University, Tuskegee, AL 36088, USA
| | - Pallavi Somvanshi
- Department of Biotechnology, TERI University, 10, Institutional Area, Vasantkunj, New Delhi 110070, India
| | | | - Prahlad K Seth
- Bioinformatics Centre, Biotech Park, Sector-G, Jankipuram, Lucknow-226021, Uttar Pradesh, India
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39
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Haworth NL, Wouters MA. Between-strand disulfides: forbidden disulfides linking adjacent β-strands. RSC Adv 2013. [DOI: 10.1039/c3ra42486c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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40
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Clark GA, Baleja JD, Kumar K. Cross-strand interactions of fluorinated amino acids in β-hairpin constructs. J Am Chem Soc 2012; 134:17912-21. [PMID: 23078597 DOI: 10.1021/ja212080f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We describe herein the design, synthesis, and thermodynamic characterization of fluorinated β-hairpin constructs. Introduction of hexafluoroleucine (Hfl) did not perturb β-hairpin formation, as judged by (1)H NMR structures of four peptides determined to <1 Å backbone RMSDs, allowing direct comparison of thermodynamic stabilities of fluorinated peptides to their hydrocarbon counterparts. Judicious fluorination of peptides often results in increased thermal and chemical stability of the resultant folded structures. However, we found that when cross-strand residue partners were varied, the side-chain interaction energies followed the order Leu-Leu > Hfl-Leu > Hfl-Hfl. All peptides were more structured in 90% MeOH than in aqueous buffers. The peptides with Hfl-Leu or Hfl-Hfl cross-strand partners showed increased interaction energies in this solvent compared to those in water, in contrast to the insignificant effect on Leu-Leu. Our results inform the binding and assembly of peptides containing Hfl in the context of β-sheet structures and may be useful in interpreting binding of fluorinated ligands and peptides to biological targets.
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Affiliation(s)
- Ginevra A Clark
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
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41
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Hudecová J, Horníček J, Buděšínský M, Šebestík J, Šafařík M, Zhang G, Keiderling TA, Bouř P. Three types of induced tryptophan optical activity compared in model dipeptides: theory and experiment. Chemphyschem 2012; 13:2748-60. [PMID: 22706803 DOI: 10.1002/cphc.201200201] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Revised: 04/27/2012] [Indexed: 11/08/2022]
Abstract
The tryptophan (Trp) aromatic residue in chiral matrices often exhibits a large optical activity and thus provides valuable structural information. However, it can also obscure spectral contributions from other peptide parts. To better understand the induced chirality, electronic circular dichroism (ECD), vibrational circular dichroism (VCD), and Raman optical activity (ROA) spectra of Trp-containing cyclic dipeptides c-(Trp-X) (where X = Gly, Ala, Trp, Leu, nLeu, and Pro) are analyzed on the basis of experimental spectra and density functional theory (DFT) computations. The results provide valuable insight into the molecular conformational and spectroscopic behavior of Trp. Whereas the ECD is dominated by Trp π-π* transitions, VCD is dominated by the amide modes, well separated from minor Trp contributions. The ROA signal is the most complex. However, an ROA marker band at 1554 cm(-1) indicates the local χ(2) angle value in this residue, in accordance with previous theoretical predictions. The spectra and computations also indicate that the peptide ring is nonplanar, with a shallow potential so that the nonplanarity is primarily induced by the side chains. Dispersion-corrected DFT calculations provide better results than plain DFT, but comparison with experiment suggests that they overestimate the stability of the folded conformers. Molecular dynamics simulations and NMR results also confirm a limited accuracy of the dispersion-DFT model in nonaqueous solvents. Combination of chiral spectroscopies with theoretical analysis thus significantly enhances the information that can be obtained from the induced chirality of the Trp aromatic residue.
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Affiliation(s)
- Jana Hudecová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo náměstí 2, 16610 Prague 6, Czech Republic.
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42
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Culik RM, Jo H, DeGrado WF, Gai F. Using thioamides to site-specifically interrogate the dynamics of hydrogen bond formation in β-sheet folding. J Am Chem Soc 2012; 134:8026-9. [PMID: 22540162 PMCID: PMC3354031 DOI: 10.1021/ja301681v] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Thioamides are sterically almost identical to their oxoamide counterparts, but they are weaker hydrogen bond acceptors. Therefore, thioamide amino acids are excellent candidates for perturbing the energetics of backbone-backbone H-bonds in proteins and hence should be useful in elucidating protein folding mechanisms in a site-specific manner. Herein, we validate this approach by applying it to probe the dynamic role of interstrand H-bond formation in the folding kinetics of a well-studied β-hairpin, tryptophan zipper. Our results show that reducing the strength of the peptide's backbone-backbone H-bonds, except the one directly next to the β-turn, does not change the folding rate, suggesting that most native interstrand H-bonds in β-hairpins are formed only after the folding transition state.
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Affiliation(s)
- Robert M Culik
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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43
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Wu X, Yang G, Zu Y, Zhou L. Molecular dynamics studies of β-hairpin folding with the presence of the sodium ion. Comput Biol Chem 2012; 38:1-9. [PMID: 22487489 DOI: 10.1016/j.compbiolchem.2012.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 01/20/2012] [Accepted: 02/14/2012] [Indexed: 11/19/2022]
Abstract
Metal ions are ubiquitous in protein systems and play a significant role during their folding processes. Nineteen independent structures were determined for the Na(+)/β-hairpin interacting systems, and their folding pathways are different. (i) For Na(S47), the turn is rapidly shaped with the help of Na(+) and acts as the folding nucleus for the rest regions. Two intermediate states are observed and the resulted structure is the most folded. (ii) For Na(B41), Na(B52), Na(B54), Na(S55) and Na(B56), the inclusive Na(+) ions are anchored by β-strands. The local structures around the Na(+) ions and the turn regions fold simultaneously and serve as two independent folding nuclei. (iii) The other systems have no folding nuclei and correspond to low-folded structures. Long-range electrostatic interactions contribute a lot to the folding, especially from the four negatively charged residues (Glu42, Asp46, Asp47 and Glu56). The initial positions of the Na(+) ions are largely responsible for the different folding behaviors. The interactions with sidechain- rather than backbone-O atoms generally lead to more compact structures. Another factor affecting the folding is whether the O atoms are associated with native H-bonds, and those involved show decreased affinities to metal ions. The addition of water solvent does not induce obvious folding and conformational transitions to the Na(+)/β-hairpin interacting systems.
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Affiliation(s)
- Xiaomin Wu
- Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, PR China
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44
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45
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Wu X, Yang G, Zu Y, Fu Y, Zhou L, Yuan X. Molecular dynamics characterisations of the Trp-cage folding mechanisms: in the absence and presence of water solvents. MOLECULAR SIMULATION 2012. [DOI: 10.1080/08927022.2011.610795] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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46
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Impact ofβ-Turn Sequence onβ-Hairpin Dynamics Studied with Infrared-Detected Temperature Jump. ACTA ACUST UNITED AC 2012. [DOI: 10.1155/2012/102423] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Folding dynamics forβ-structure loss and disordered structure gain were studied in a modelβ-hairpin peptide based on Cochran’s tryptophan zipper peptide Trpzip2, but with an altered Thr-Gly (TG) turn sequence, that is, SWTWETGKWTWK, using laser-induced temperature-jump (T-jump) kinetics with IR detection. As has been shown previously, the TG turn sequence reduces the thermodynamicβ-hairpin stability as compared to the Asn-Gly sequence used in Trpzip2 (TZ2-NG). In this study, we found that the TG-turn slows down the overall relaxation dynamics as compared to TZ2-NG, which were studied at higher temperatures where the time constants show little difference between relaxation of theβ-strand and the disordered conformation. These time constants become equivalent at lower temperatures for TZ2-TG than was seen for TZ2-NG. The correlation of thermodynamic stability and rates of relaxation suggests that the change from NG to TG turn results in a slowing of folding, lowerkf, with less change of the unfolding rate,ku, assuming two state behavior at higher temperatures.
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47
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Wu L, McElheny D, Setnicka V, Hilario J, Keiderling TA. Role of different β-turns in β-hairpin conformation and stability studied by optical spectroscopy. Proteins 2011; 80:44-60. [DOI: 10.1002/prot.23140] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 06/28/2011] [Accepted: 07/21/2011] [Indexed: 12/28/2022]
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48
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Diana D, Basile A, De Rosa L, Di Stasi R, Auriemma S, Arra C, Pedone C, Turco MC, Fattorusso R, D'Andrea LD. β-hairpin peptide that targets vascular endothelial growth factor (VEGF) receptors: design, NMR characterization, and biological activity. J Biol Chem 2011; 286:41680-41691. [PMID: 21969375 DOI: 10.1074/jbc.m111.257402] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
VEGF receptors have been the target of intense research aimed to develop molecules able to inhibit or stimulate angiogenesis. Based on the x-ray structure of the complex placental growth factor-VEGF receptor 1(D2), we designed a VEGF receptor-binding peptide reproducing the placental growth factor β-hairpin region Gln(87)-Val(100) that is involved in receptor recognition. A conformational analysis showed that the designed peptide adopts the expected fold in pure water. Moreover, a combination of NMR interaction analysis and cell binding studies were used to demonstrate that the peptide targets VEGF receptors. The VEGF receptor 1(D2)-interacting residues were characterized at the molecular level, and they correspond to the residues recognizing the placental growth factor sequence Gln(87)-Val(100). Finally, the peptide biological activity was characterized in vitro and in vivo, and it showed a VEGF-like behavior. Indeed, the peptide activated VEGF-dependent intracellular pathways, induced endothelial cell proliferation and rescue from apoptosis, and promoted angiogenesis in vivo. This compound is one of the few peptides known with proangiogenic activity, which makes it a candidate for the development of a novel peptide-based drug for medical applications in therapeutic angiogenesis.
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Affiliation(s)
- Donatella Diana
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, via Mezzocannone 16, 80134 Napoli, Italy
| | - Anna Basile
- Dipartimento di Scienze Farmaceutiche e Biomediche, Università di Salerno, via Ponte don Melillo, 84084 Fisciano (Salerno), Italy
| | - Lucia De Rosa
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, via Mezzocannone 16, 80134 Napoli, Italy
| | - Rossella Di Stasi
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, via Mezzocannone 16, 80134 Napoli, Italy
| | - Sara Auriemma
- Dipartimento delle Scienze Biologiche, Università di Napoli "Federico II," via Mezzocannone 16, 80134 Napoli, Italy
| | - Claudio Arra
- Istituto Nazionale Tumori "Fondazione G. Pascale," via Mariano Semmola 49, 80131 Napoli, Italy
| | - Carlo Pedone
- Dipartimento delle Scienze Biologiche, Università di Napoli "Federico II," via Mezzocannone 16, 80134 Napoli, Italy
| | - Maria Caterina Turco
- Dipartimento di Scienze Farmaceutiche e Biomediche, Università di Salerno, via Ponte don Melillo, 84084 Fisciano (Salerno), Italy
| | - Roberto Fattorusso
- Dipartimento di Scienze Ambientali, Seconda Università di Napoli, via Antonio Vivaldi 43, 81100 Caserta, Italy
| | - Luca Domenico D'Andrea
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, via Mezzocannone 16, 80134 Napoli, Italy.
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49
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Santiveri CM, Jiménez MA. Tryptophan residues: scarce in proteins but strong stabilizers of β-hairpin peptides. Biopolymers 2011; 94:779-90. [PMID: 20564027 DOI: 10.1002/bip.21436] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Tryptophan plays important roles in protein stability and recognition despite its scarcity in proteins. Except as fluorescent groups, they have been used rarely in peptide design. Nevertheless, Trp residues were crucial for the stability of some designed minimal proteins. In 2000, Trp-Trp pairs were shown to contribute more than any other hydrophobic interaction to the stability of β-hairpin peptides. Since then, Trp-Trp pairs have emerged as a paradigm for the design of stable β-hairpins, such as the Trpzip peptides. Here, we analyze the nature of the stabilizing capacity of Trp-Trp pairs by reviewing the β-hairpin peptides containing Trp-Trp pairs described up to now, the spectroscopic features and geometry of the Trp-Trp pairs, and their use as binding sites in β-hairpin peptides. To complete the overview, we briefly go through the other relevant β-hairpin stabilizing Trp-non-Trp interactions and illustrate the use of Trp in the design of short peptides adopting α-helical and mixed α/β motifs. This review is of interest in the field of rational design of proteins, peptides, peptidomimetics, and biomaterials.
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Affiliation(s)
- Clara M Santiveri
- Instituto de Química Física Rocasolano, CSIC, Serrano 119, Madrid 28006, Spain
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50
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Shu I, Stewart JM, Scian M, Kier BL, Andersen NH. β-Sheet 13C structuring shifts appear only at the H-bonded sites of hairpins. J Am Chem Soc 2011; 133:1196-9. [PMID: 21214243 DOI: 10.1021/ja1088953] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The (13)C chemical shifts measured for designed β-hairpins indicate that the structuring shifts (upfield for Cα and C', downfield for Cβ) previously reported as diagnostic for β-structuring in proteins appear only at the H-bonded strand residues. The resulting periodicity of structuring shift magnitudes is not, however, a consequence of H-bonding status; rather, it reflects a previously unrecognized alternation in the backbone torsion angles of β-strands. This feature of hairpins is also likely to be present in proteins. The study provides reference values for the expectation shifts for (13)C sites in β-structures that should prove useful in the characterization of the folding equilibria of β-sheet models.
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Affiliation(s)
- Irene Shu
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
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