1
|
Bressler SG, Mitrany A, Wenger A, Näthke I, Friedler A. The Oligomerization Domains of the APC Protein Mediate Liquid-Liquid Phase Separation That Is Phosphorylation Controlled. Int J Mol Sci 2023; 24:ijms24076478. [PMID: 37047451 PMCID: PMC10095272 DOI: 10.3390/ijms24076478] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/25/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023] Open
Abstract
One of the most important properties of intrinsically disordered proteins is their ability to undergo liquid-liquid phase separation and form droplets. The Adenomatous Polyposis Coli (APC) protein is an IDP that plays a key role in Wnt signaling and mutations in Apc initiate cancer. APC forms droplets via its 20R domains and self-association domain (ASAD) and in the context of Axin. However, the mechanism involved is unknown. Here, we used peptides to study the molecular mechanism and regulation of APC droplet formation. We found that a peptide derived from the ASAD of APC-formed droplets. Peptide array screening showed that the ASAD bound other APC peptides corresponding to the 20R3 and 20R5 domains. We discovered that the 20R3/5 peptides also formed droplets by themselves and mapped specific residues within 20R3/5 that are necessary for droplet formation. When incubated together, the ASAD and 20R3/5 did not form droplets. Thus, the interaction of the ASAD with 20R3 and 20R5 may regulate the droplet formation as a means of regulating different cellular functions. Phosphorylation of 20R3 or 20R5 at specific residues prevented droplet formation of 20R3/5. Our results reveal that phosphorylation and the ability to undergo liquid-liquid phase separation, which are both important properties of intrinsically disordered proteins, are related to each other in APC. Phosphorylation inhibited the liquid-liquid phase separation of APC, acting as an ‘on-off’ switch for droplet formation. Phosphorylation may thus be a common mechanism regulating LLPS in intrinsically disordered proteins.
Collapse
Affiliation(s)
- Shachar G. Bressler
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Amit Mitrany
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Alon Wenger
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
| | - Inke Näthke
- Division of Molecular Cell and Developmental Biology, University of Dundee, Dundee DD1 5AA, Scotland, UK
- Correspondence: (I.N.); (A.F.)
| | - Assaf Friedler
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904, Israel
- Correspondence: (I.N.); (A.F.)
| |
Collapse
|
2
|
Mayer G, Shpilt Z, Kowalski H, Tshuva EY, Friedler A. Targeting Protein Interaction Hotspots Using Structured and Disordered Chimeric Peptide Inhibitors. ACS Chem Biol 2022; 17:1811-1823. [PMID: 35758642 DOI: 10.1021/acschembio.2c00177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The main challenge in inhibiting protein-protein interactions (PPI) for therapeutic purposes is designing molecules that bind specifically to the interaction hotspots. Adding to the complexity, such hotspots can be within both structured and disordered interaction interfaces. To address this, we present a strategy for inhibiting the structured and disordered hotspots of interactions using chimeric peptides that contain both structured and disordered parts. The chimeric peptides we developed are comprised of a cyclic structured part and a disordered part, which target both disordered and structured hotspots. We demonstrate our approach by developing peptide inhibitors for the interactions of the antiapoptotic iASPP protein. First, we developed a structured, α-helical stapled peptide inhibitor, derived from the N-terminal domain of MDM2. The peptide bound two hotspots on iASPP at the low micromolar range and had a cytotoxic effect on A2780 cancer cells with a half-maximal inhibitory concentration (IC50) value of 10 ± 1 μM. We then developed chimeric peptides comprising the structured stapled helical peptide and the disordered p53-derived LinkTer peptide that we previously showed to inhibit iASPP by targeting its disordered RT loop. The chimeric peptide targeted both structured and disordered domains in iASPP with higher affinity compared to the individual structured and disordered peptides and caused cancer cell death. Our strategy overcomes the inherent difficulty in inhibiting the interactions of proteins that possess structured and disordered regions. It does so by using chimeric peptides derived from different interaction partners that together target a much wider interface covering both the structured and disordered domains. This paves the way for developing such inhibitors for therapeutic purposes.
Collapse
Affiliation(s)
- Guy Mayer
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Zohar Shpilt
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Hadar Kowalski
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Edit Y Tshuva
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| | - Assaf Friedler
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel
| |
Collapse
|
3
|
Sohn YS, Losub-Amir A, Cardenas AE, Karmi O, Yahana MD, Gruman T, Rowland L, Marjault HB, Webb LJ, Mittler R, Elber R, Friedler A, Nechushtai R. A peptide-derived strategy for specifically targeting the mitochondria and ER of cancer cells: a new approach in fighting cancer. Chem Sci 2022; 13:6929-6941. [PMID: 35774163 PMCID: PMC9200128 DOI: 10.1039/d2sc01934e] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 04/18/2022] [Indexed: 12/13/2022] Open
Abstract
An effective anti-cancer therapy should exclusively target cancer cells and trigger in them a broad spectrum of cell death pathways that will prevent avoidance. Here, we present a new approach in cancer therapy that specifically targets the mitochondria and ER of cancer cells. We developed a peptide derived from the flexible and transmembrane domains of the human protein NAF-1/CISD2. This peptide (NAF-144-67) specifically permeates through the plasma membranes of human epithelial breast cancer cells, abolishes their mitochondria and ER, and triggers cell death with characteristics of apoptosis, ferroptosis and necroptosis. In vivo analysis revealed that the peptide significantly decreases tumor growth in mice carrying xenograft human tumors. Computational simulations of cancer vs. normal cell membranes reveal that the specificity of the peptide to cancer cells is due to its selective recognition of their membrane composition. NAF-144-67 represents a promising anti-cancer lead compound that acts via a unique mechanism.
Collapse
Affiliation(s)
- Yang Sung Sohn
- The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram Jerusalem 9190401 Israel
| | - Anat Losub-Amir
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram Jerusalem 9190401 Israel
| | - Alfredo E Cardenas
- Institute for Computational Engineering and Science and Department of Chemistry, University of Texas at Austin Austin Texas 78712 USA
| | - Ola Karmi
- The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram Jerusalem 9190401 Israel
- Department of Surgery, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center University of Missouri. 1201 Rollins St Columbia MO 65201 USA
| | - Merav Darash Yahana
- The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram Jerusalem 9190401 Israel
| | - Tal Gruman
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram Jerusalem 9190401 Israel
| | - Linda Rowland
- Department of Surgery, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center University of Missouri. 1201 Rollins St Columbia MO 65201 USA
| | - Henri-Baptiste Marjault
- The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram Jerusalem 9190401 Israel
| | - Lauren J Webb
- Department of Chemistry, The University of Texas at Austin 2506 Speedway STOP A5300 Austin TX 78712 USA
| | - Ron Mittler
- Department of Surgery, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center University of Missouri. 1201 Rollins St Columbia MO 65201 USA
| | - Ron Elber
- Institute for Computational Engineering and Science and Department of Chemistry, University of Texas at Austin Austin Texas 78712 USA
| | - Assaf Friedler
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram Jerusalem 9190401 Israel
| | - Rachel Nechushtai
- The Alexander Silberman Institute of Life Science, The Hebrew University of Jerusalem, Edmond J. Safra Campus at Givat Ram Jerusalem 9190401 Israel
| |
Collapse
|
4
|
Mayer G, Shpilt Z, Bressler S, Marcu O, Schueler-Furman O, Tshuva EY, Friedler A. Targeting an Interaction Between Two Disordered Domains by Using a Designed Peptide. Chemistry 2020; 26:10240-10249. [PMID: 32181542 DOI: 10.1002/chem.202000465] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/14/2020] [Indexed: 11/09/2022]
Abstract
Intrinsically disordered regions in proteins (IDRs) mediate many disease-related protein-protein interactions. However, the unfolded character and continuous conformational changes of IDRs make them difficult to target for therapeutic purposes. Here, we show that a designed peptide based on the disordered p53 linker domain can be used to target a partner IDR from the anti-apoptotic iASPP protein, promoting apoptosis of cancer cells. The p53 linker forms a hairpin-like structure with its two termini in close proximity. We designed a peptide derived from the disordered termini without the hairpin, designated as p53 LinkTer. The LinkTer peptide binds the disordered RT loop of iASPP with the same affinity as the parent p53 linker peptide, and inhibits the p53-iASPP interaction in vitro. The LinkTer peptide shows increased stability to proteolysis, penetrates cancer cells, causes nuclei shrinkage, and compromises the viability of cells. We conclude that a designed peptide comprising only the IDR from a peptide sequence can serve as an improved inhibitor since it binds its target protein without the need for pre-folding, paving the way for therapeutic targeting of IDRs.
Collapse
Affiliation(s)
- Guy Mayer
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel
| | - Zohar Shpilt
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel
| | - Shachar Bressler
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel
| | - Orly Marcu
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Edit Y Tshuva
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel
| | - Assaf Friedler
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel
| |
Collapse
|
5
|
Samarasimhareddy M, Shamir M, Shalev DE, Hurevich M, Friedler A. A Rapid and Efficient Building Block Approach for Click Cyclization of Peptoids. Front Chem 2020; 8:405. [PMID: 32509731 PMCID: PMC7248394 DOI: 10.3389/fchem.2020.00405] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/17/2020] [Indexed: 12/18/2022] Open
Abstract
Cyclic peptide-peptoid hybrids possess improved stability and selectivity over linear peptides and are thus better drug candidates. However, their synthesis is far from trivial and is usually difficult to automate. Here we describe a new rapid and efficient approach for the synthesis of click-based cyclic peptide-peptoid hybrids. Our methodology is based on a combination between easily synthesized building blocks, automated microwave assisted solid phase synthesis and bioorthogonal click cyclization. We proved the concept of this method using the INS peptide, which we have previously shown to activate the HIV-1 integrase enzyme. This strategy enabled the rapid synthesis and biophysical evaluation of a library of cyclic peptide-peptoid hybrids derived from HIV-1 integrase in high yield and purity. The new cyclic hybrids showed improved biological activity and were significantly more stable than the original linear INS peptide.
Collapse
Affiliation(s)
| | - Mai Shamir
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Deborah E. Shalev
- Wolfson Centre for Applied Structural Biology, The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Pharmaceutical Engineering, Azrieli College of Engineering Jerusalem, Jerusalem, Israel
| | - Mattan Hurevich
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Assaf Friedler
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
6
|
Vaňková E, Kašparová P, Dulíčková N, Čeřovský V. Combined effect of lasioglossin LL-III derivative with azoles against Candida albicans virulence factors: biofilm formation, phospholipases, proteases and hemolytic activity. FEMS Yeast Res 2020; 20:5824167. [DOI: 10.1093/femsyr/foaa020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 04/21/2020] [Indexed: 12/18/2022] Open
Abstract
ABSTRACT
Candida albicans has several virulence factors at its disposal, including yeast–hyphal transition associated with biofilm formation, phospholipases, proteases and hemolytic activity, all of which contribute to its pathogenesis. We used synthetic derivative LL-III/43 of antimicrobial peptide lasioglossin LL-III to enhance effect of azoles on attenuation of C. albicans virulence factors. LL-III/43 was able to inhibit initial adhesion or biofilm formation of C. albicans strains at 50 µM. Azoles, however, were ineffective at this concentration. Using fluorescently labeled LL-III/43, we observed that peptide covered C. albicans cells, partially penetrated through their membranes and then accumulated inside cells. LL-III/43 (25 µM) in combination with clotrimazole prevented biofilm formation already at 3.1 µM clotrimazole. Neither LL-III/43 nor azoles were able to significantly inhibit phospholipases, proteases, or hemolytic activity of C. albicans. LL-III/43 (25 µM) and clotrimazole (50 µM) in combination decreased production of these virulence factors, and it completely attenuated its hemolytic activity. Scanning electron microscopy showed that LL-III/43 (50 µM) prevented C. albicans biofilm formation on Ti-6Al-4 V alloy used in orthopedic surgeries and combination of LL-III/43 (25 µM) with clotrimazole (3.1 µM) prevented biofilm formation on urinary catheters. Therefore, mixture of LL-III/43 and clotrimazole is suitable candidate for future pharmaceutical research.
Collapse
Affiliation(s)
- Eva Vaňková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 166 10, Prague, Czech Republic
- University of Chemistry and Technology Prague, Technická 5, 166 28, Prague, Czech Republic
| | - Petra Kašparová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 166 10, Prague, Czech Republic
- University of Chemistry and Technology Prague, Technická 5, 166 28, Prague, Czech Republic
| | - Nikola Dulíčková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 166 10, Prague, Czech Republic
- University of Chemistry and Technology Prague, Technická 5, 166 28, Prague, Czech Republic
| | - Václav Čeřovský
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 166 10, Prague, Czech Republic
| |
Collapse
|
7
|
Fluorescent Analogues of Human α-Calcitonin Gene-Related Peptide with Potent Vasodilator Activity. Int J Mol Sci 2020; 21:ijms21041343. [PMID: 32079247 PMCID: PMC7072916 DOI: 10.3390/ijms21041343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 01/31/2023] Open
Abstract
Human α-calcitonin gene-related peptide (h-α-CGRP) is a highly potent vasodilator peptide that belongs to the family of calcitonin peptides. There are two forms of CGRP receptors in humans and rodents: α-CGRP receptor predominately found in the cardiovascular system and β-CGRP receptor predominating in the gastrointestinal tract. The CGRP receptors are primarily localized to C and Aδ sensory fibers, where they are involved in nociceptive transmission and migraine pathophysiology. These fibers are found both peripherally and centrally, with extensive perivascular location. The CGRP receptors belong to the class B G-protein-coupled receptors, and they are primarily associated to signaling via Gα proteins. The objectives of the present work were: (i) synthesis of three single-labelled fluorescent analogues of h-α-CGRP by 9-fluorenylmethyloxycarbonyl (Fmoc)-based solid-phase peptide synthesis, and (ii) testing of their biological activity in isolated human, mouse, and rat arteries by using a small-vessel myograph setup. The three analogues were labelled with 5(6)-carboxyfluorescein via the spacer 6-aminohexanoic acid at the chain of Lys24 or Lys35. Circular dichroism (CD) experiments were performed to obtain information on the secondary structure of these fluorescently labelled peptides. The CD spectra indicated that the folding of all three analogues was similar to that of native α-CGRP. The three fluorescent analogues of α-CGRP were successfully prepared with a purity of >95%. In comparison to α-CGRP, the three analogues exhibited similar efficacy, but different potency in producing a vasodilator effect. The analogue labelled at the N-terminus proved to be the most readily synthesized, but it was found to possess the lowest vasodilator potency. The analogues labelled at Lys35 or Lys24 exhibited an acceptable reduction in potency (i.e., 3–5 times and 5–10 times less potent, respectively), and thus they have potential for use in further investigations of receptor internalization and neuronal reuptake.
Collapse
|
8
|
Huang M, Liu Y, Yang G, Klier J, Schiffman JD. Anionic Polymerization of Methylene Malonate for High-Performance Coatings. ACS APPLIED POLYMER MATERIALS 2019; 1:657-663. [PMID: 31650131 PMCID: PMC6812519 DOI: 10.1021/acsapm.8b00135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Here, we demonstrate the anionic polymerization and the high reactivity of the novel monomer diethyl methylene malonate (DEMM). At room temperature and under atmospheric conditions, water and anionic functional groups (i.e., carboxyl, boronic, and phenol) quickly initiate DEMM. The polymerization of DEMM in water and the final molecular weight of the polymer were both demonstrated to be pH-dependent. Systematically, investigations were conducted to study the conversion rate of DEMM with various functional groups, and the polymerization was verified to occur with anionic groups using a carboxylate-initiated DEMM system. For coating applications, we also investigated a multifunctional derivative monomer called (DEMM)6 that is an oligomeric polyester of DEMM esterified with butanediol that contains on average six repeat units of reactive DEMM (commercially known as Forza B3000 XP). The incorporation of 15 wt % (DEMM)6 into latex containing methacrylate acid as a functional monomer yielded cross-linked coatings with a gel content of 76.25 wt % that had a 289% improvement in rub-resistance performance compared to controls (without (DEMM)6). This study provides a facile methodology to synthesize cross-linked latex coatings at room temperature.
Collapse
|
9
|
Iosub-Amir A, Bai F, Sohn YS, Song L, Tamir S, Marjault HB, Mayer G, Karmi O, Jennings PA, Mittler R, Onuchic JN, Friedler A, Nechushtai R. The anti-apoptotic proteins NAF-1 and iASPP interact to drive apoptosis in cancer cells. Chem Sci 2018; 10:665-673. [PMID: 30774867 PMCID: PMC6349067 DOI: 10.1039/c8sc03390k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 11/19/2018] [Indexed: 01/01/2023] Open
Abstract
We reveal a novel interaction between the two anti-apoptotic proteins iASPP and NAF-1, which are overexpressed in many types of cancer cells, and propose that this interaction is required for apoptosis activation in cancer cells. A peptide derived from the interaction interface inhibits apoptosis in cells.
Suppression of apoptosis is a key Hallmark of cancer cells, and reactivation of apoptosis is a major avenue for cancer therapy. We reveal an interaction between the two anti-apoptotic proteins iASPP and NAF-1, which are overexpressed in many types of cancer cells and tumors. iASPP is an inhibitory member of the ASPP protein family, whereas NAF-1 belongs to the NEET 2Fe–2S protein family. We show that the two proteins are stimulated to interact in cells during apoptosis. Using peptide array screening and computational methods we mapped the interaction interfaces of both proteins to residues 764–778 of iASPP that bind to a surface groove of NAF-1. A peptide corresponding to the iASPP 764–780 sequence stabilized the NAF-1 cluster, inhibited NAF-1 interaction with iASPP, and inhibited staurosporine-induced apoptosis activation in human breast cancer, as well as in PC-3 prostate cancer cells in which p53 is inactive. The iASPP 764–780 IC50 value for inhibition of cell death in breast cancer cells was 13 ± 1 μM. The level of cell death inhibition by iASPP 764–780 was altered in breast cancer cells expressing different levels and/or variants of NAF-1, indicating that the peptide activity is associated with NAF-1 function. We propose that the interaction between iASPP and NAF-1 is required for apoptosis activation in cancer cells. This interaction uncovers a new layer in the highly complex regulation of cell death in cancer cells and opens new avenues of exploration into the development of novel anticancer drugs that reactivate apoptosis in malignant tumors.
Collapse
Affiliation(s)
- Anat Iosub-Amir
- Institute of Chemistry , The Hebrew University of Jerusalem , Edmond J. Safra Campus at Givat Ram , Jerusalem 91904 , Israel .
| | - Fang Bai
- Center for Theoretical Biological Physics , Department of Physics , Rice University , Houston , TX 77005 , USA .
| | - Yang-Sung Sohn
- The Alexander Silberman Institute of Life Science , The Hebrew University of Jerusalem , Edmond J. Safra Campus at Givat Ram , Jerusalem 91904 , Israel .
| | - Luhua Song
- Department of Biological Sciences , University of North Texas , Denton , TX 76203 , USA
| | - Sagi Tamir
- The Alexander Silberman Institute of Life Science , The Hebrew University of Jerusalem , Edmond J. Safra Campus at Givat Ram , Jerusalem 91904 , Israel .
| | - Henri-Baptiste Marjault
- The Alexander Silberman Institute of Life Science , The Hebrew University of Jerusalem , Edmond J. Safra Campus at Givat Ram , Jerusalem 91904 , Israel .
| | - Guy Mayer
- Institute of Chemistry , The Hebrew University of Jerusalem , Edmond J. Safra Campus at Givat Ram , Jerusalem 91904 , Israel .
| | - Ola Karmi
- The Alexander Silberman Institute of Life Science , The Hebrew University of Jerusalem , Edmond J. Safra Campus at Givat Ram , Jerusalem 91904 , Israel .
| | - Patricia A Jennings
- Department of Chemistry & Biochemistry , University of California at San Diego , La Jolla , CA 92093 , USA
| | - Ron Mittler
- Department of Surgery , University of Missouri School of Medicine , Christopher S. Bond Life Sciences Center , University of Missouri , 1201 Rollins St , Columbia , MO 65201 , USA
| | - José N Onuchic
- Center for Theoretical Biological Physics , Department of Physics , Rice University , Houston , TX 77005 , USA .
| | - Assaf Friedler
- Institute of Chemistry , The Hebrew University of Jerusalem , Edmond J. Safra Campus at Givat Ram , Jerusalem 91904 , Israel .
| | - Rachel Nechushtai
- The Alexander Silberman Institute of Life Science , The Hebrew University of Jerusalem , Edmond J. Safra Campus at Givat Ram , Jerusalem 91904 , Israel .
| |
Collapse
|
10
|
Ikeda K, Horiuchi A, Egawa A, Tamaki H, Fujiwara T, Nakano M. Nanodisc-to-Nanofiber Transition of Noncovalent Peptide-Phospholipid Assemblies. ACS OMEGA 2017; 2:2935-2944. [PMID: 31457628 PMCID: PMC6641012 DOI: 10.1021/acsomega.7b00424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 06/09/2017] [Indexed: 06/10/2023]
Abstract
We report a novel molecular architecture of peptide-phospholipid coassemblies. The amphiphilic peptide Ac-18A-NH2 (18A), which was designed to mimic apolipoprotein α-helices, has been shown to form nanodisc structures with phospholipid bilayers. We show that an 18A peptide cysteine substitution at residue 11, 18A[A11C], forms fibrous assemblies with 1-palmitoyl-2-oleoyl-phosphatidylcholine at a lipid-to-peptide (L/P) molar ratio of 1, a fiber diameter of 10-20 nm, and a length of more than 1 μm. Furthermore, 18A[A11C] can form nanodiscs with these lipid bilayers at L/P ratios of 4-6. The peptide adopts α-helical structures in both the nanodisc and nanofiber assemblies, although the α-helical bundle structures were evident only in the nanofibers, and the phospholipids of the nanofibers were not lamellar. Fluorescence spectroscopic analysis revealed that the peptide and lipid molecules in the nanofibers exhibited different solvent accessibility and hydrophobicity from those of the nanodiscs. Furthermore, the cysteine substitution at residue 11 did not result in disulfide bond formation, although it was responsible for the nanofiber formation, suggesting that this free sulfhydryl group has an important functional role. Alternatively, the disulfide dimer of 18A[A11C] preferentially formed nanodiscs, even at an L/P ratio of 1. Interconversions of these discoidal and fibrous assemblies were induced by the stepwise addition of free 18A[A11C] or liposomes into the solution. Furthermore, these structural transitions could also be induced by the introduction of oxidative and reductive stresses to the assemblies. Our results demonstrate that heteromolecular lipid-peptide complexes represent a novel approach to the construction of controllable and functional nanoscale assemblies.
Collapse
Affiliation(s)
- Keisuke Ikeda
- Graduate
School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Ayame Horiuchi
- Graduate
School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Ayako Egawa
- Institute
for Protein Research, Osaka University, 3-2 Yamadaoka, Suita 565-0871, Japan
| | - Hajime Tamaki
- Institute
for Protein Research, Osaka University, 3-2 Yamadaoka, Suita 565-0871, Japan
| | - Toshimichi Fujiwara
- Institute
for Protein Research, Osaka University, 3-2 Yamadaoka, Suita 565-0871, Japan
| | - Minoru Nakano
- Graduate
School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| |
Collapse
|
11
|
Dhindwal S, Kesari P, Singh H, Kumar P, Tomar S. Conformer and pharmacophore based identification of peptidomimetic inhibitors of chikungunya virus nsP2 protease. J Biomol Struct Dyn 2016; 35:3522-3539. [DOI: 10.1080/07391102.2016.1261046] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Sonali Dhindwal
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Pooja Kesari
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Harvijay Singh
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Pravindra Kumar
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Shailly Tomar
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| |
Collapse
|
12
|
Hall MD, Yasgar A, Peryea T, Braisted JC, Jadhav A, Simeonov A, Coussens NP. Fluorescence polarization assays in high-throughput screening and drug discovery: a review. Methods Appl Fluoresc 2016; 4:022001. [PMID: 28809163 DOI: 10.1088/2050-6120/4/2/022001] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The sensitivity of fluorescence polarization (FP) and fluorescence anisotropy (FA) to molecular weight changes has enabled the interrogation of diverse biological mechanisms, ranging from molecular interactions to enzymatic activity. Assays based on FP/FA technology have been widely utilized in high-throughput screening (HTS) and drug discovery due to the homogenous format, robust performance and relative insensitivity to some types of interferences, such as inner filter effects. Advancements in assay design, fluorescent probes, and technology have enabled the application of FP assays to increasingly complex biological processes. Herein we discuss different types of FP/FA assays developed for HTS, with examples to emphasize the diversity of applicable targets. Furthermore, trends in target and fluorophore selection, as well as assay type and format, are examined using annotated HTS assays within the PubChem database. Finally, practical considerations for the successful development and implementation of FP/FA assays for HTS are provided based on experience at our center and examples from the literature, including strategies for flagging interference compounds among a list of hits.
Collapse
Affiliation(s)
- Matthew D Hall
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | | | | | | | | | | | | |
Collapse
|
13
|
Francoia JP, Pascal R, Vial L. Monitoring clinical levels of heparin in human blood samples with an indicator-displacement assay. Chem Commun (Camb) 2015; 51:1953-6. [PMID: 25531454 DOI: 10.1039/c4cc08563a] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We report that a "tree-like" polymer of lysine is able to form a multi-ligand complex with a fluorescently labelled peptide, leading to the almost complete extinction of the optical signal that can be restored upon the introduction of heparin. This simple system allows, for the first time, the turn-ON fluorescent sensing of the anticoagulant in human blood at clinically relevant levels.
Collapse
Affiliation(s)
- Jean-Patrick Francoia
- Institut des Biomolécules Max Mousseron, UMR 5247 CNRS - Université de Montpellier, Place Eugène Bataillon, cc 1706, 34296 Montpellier cedex 5, France.
| | | | | |
Collapse
|
14
|
Mathew B, Nagaraj R. Antimicrobial activity of human α-defensin 6 analogs: insights into the physico-chemical reasons behind weak bactericidal activity of HD6 in vitro. J Pept Sci 2015; 21:811-8. [PMID: 26400692 DOI: 10.1002/psc.2821] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/29/2015] [Accepted: 08/19/2015] [Indexed: 01/07/2023]
Abstract
Human α-defensin 6 (HD6), unlike other mammalian defensins, does not exhibit bactericidal activity, particularly against aerobic bacteria. Monomeric HD6 has a tertiary structure similar to other α-defensins in the crystalline state. However, the physico-chemical reasons behind the lack of antibacterial activity of HD6 are yet to be established unequivocally. In this study, we have investigated the antimicrobial activity of HD6 analogs. A linear analog of HD6, in which the distribution of arginine residues was similar to active α-defensins, shows broad-spectrum antimicrobial activity, indicating that atypical distribution of arginine residues contributes to the inactivity of HD6. Peptides spanning the N-terminal cationic segment were active against a wide range of organisms. Antimicrobial potency of these shorter analogs was further enhanced when myristic acid was conjugated at the N-terminus. Cytoplasmic localization of the analogs without fatty acylation was observed to be necessary for bacterial killing, while they exhibited fungicidal activity by permeabilizing Candida albicans membranes. Myristoylated analogs and the linear full-length arginine analog exhibited activity by permeabilizing bacterial and fungal membranes. Our study provides insights into the lack of bactericidal activity of HD6 against aerobic bacteria.
Collapse
Affiliation(s)
- Basil Mathew
- CSIR - Centre for Cellular and Molecular Biology, Hyderabad, 500 007, India
| | | |
Collapse
|
15
|
Mathew B, Nagaraj R. Antimicrobial activity of human α-defensin 5 and its linear analogs: N-terminal fatty acylation results in enhanced antimicrobial activity of the linear analogs. Peptides 2015. [PMID: 26206286 DOI: 10.1016/j.peptides.2015.07.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Human α-defensin 5 (HD5) exhibits broad spectrum antimicrobial activity and plays an important role in mucosal immunity of the small intestine. Although there have been several studies, the structural requirements for activity and mechanism of bacterial killing is yet to be established unequivocally. In this study, we have investigated the antimicrobial activity of HD5 and linear analogs. Cysteine deletions attenuated the antibacterial activity considerably. Candidacidal activity was affected to a lesser extent. Fatty acid conjugated linear analogs showed antimicrobial activity comparable activity to HD5. Effective surface charge neutralization of bacteria was observed for HD5 as compared to the non-fatty acylated linear analogs. Our results show that HD5 and non-fatty acylated linear analogs enter the bacterial cytoplasm without causing damage to the bacterial inner membrane. Although fatty acylated peptides exhibited antimicrobial activity comparable to HD5, their mechanism of action involved permeabilization of the Escherichia coli inner membrane. HD5 and analogs had the ability to bind plasmid DNA. HD5 had greater binding affinity to plasmid DNA as compared to the analogs. The three dimensional structure of HD5 favors greater interaction with the bacterial cell surface and also with DNA. Antibacterial activity of HD5 involves entry into bacterial cytoplasm and binding to DNA which would result in shut down of the bacterial metabolism leading to cell death. We show how a moderately active linear peptide derived from the α-defensin HD5 can be engineered to enhance antimicrobial activity almost comparable to the native peptide.
Collapse
Affiliation(s)
- Basil Mathew
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | - Ramakrishnan Nagaraj
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India.
| |
Collapse
|
16
|
Highly homologous proteins exert opposite biological activities by using different interaction interfaces. Sci Rep 2015; 5:11629. [PMID: 26130271 PMCID: PMC4486954 DOI: 10.1038/srep11629] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/02/2015] [Indexed: 11/08/2022] Open
Abstract
We present a possible molecular basis for the opposite activity of two homologues proteins that bind similar ligands and show that this is achieved by fine-tuning of the interaction interface. The highly homologous ASPP proteins have opposite roles in regulating apoptosis: ASPP2 induces apoptosis while iASPP inhibits it. The ASPP proteins are regulated by an autoinhibitory interaction between their Ank-SH3 and Pro domains. We performed a detailed biophysical and molecular study of the Pro - Ank-SH3 interaction in iASPP and compared it to the interaction in ASPP2. We found that iASPP Pro is disordered and that the interaction sites are entirely different: iASPP Ank-SH3 binds iASPP Pro via its fourth Ank repeat and RT loop while ASPP2 Ank-SH3 binds ASPP2 Pro via its first Ank repeat and the n-src loop. It is possible that by using different moieties in the same interface, the proteins can have distinct and specific interactions resulting in differential regulation and ultimately different biological activities.
Collapse
|
17
|
Sharma H, Mathew B, Nagaraj R. Engineering of a linear inactive analog of human β-defensin 4 to generate peptides with potent antimicrobial activity. J Pept Sci 2015; 21:501-11. [PMID: 25810238 DOI: 10.1002/psc.2770] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 02/12/2015] [Accepted: 02/13/2015] [Indexed: 02/01/2023]
Abstract
Human β-defensins (HBDs) are cationic antimicrobial peptides constrained by three disulfide bridges. They have diverse range of functions in the innate immune response. It is of interest to investigate whether linear analogs of defensins can be generated, which possess antimicrobial activity. In this study, we have designed linear peptides with potent antimicrobial activity from an inactive peptide spanning the N-terminus of HBD4. Our results show that l-arginine to d-arginine substitution imparts considerable antimicrobial activity against both bacteria and Candida albicans. Increase in hydrophobicity by fatty acylation of the peptides with myristic acid further enhances their potency. In the presence of high concentrations of salt, antimicrobial activity of the myristoylated peptide with l-arginine is attenuated relatively to a lesser extent as compared with the linear active peptide with d-arginine. Substitution of cysteine with the hydrophobic helix-promoting amino acid α-aminoisobutyric acid favors candidacidal activity but not antibacterial activity. The mechanism of killing by d-arginine substituted unacylated analog involves transient interaction with the bacterial membrane followed by translocation into the cytoplasm without membrane permeabilization. Accumulation of peptides in the cytoplasm can affect various cellular processes that lead to cell death. However, the peptide causes membrane permeabilization in case of C. albicans. Myristoylation results in greater interaction of the peptide chain with the microbial cell surface and causes membrane permeabilization. Results described in the study demonstrate that it is possible to generate highly active linear analogs of defensins by selective introduction of d-amino acids and fatty acids, which could be attractive candidates for development as therapeutic agents.
Collapse
Affiliation(s)
- Himanshu Sharma
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India
| | - Basil Mathew
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India
| | - Ramakrishnan Nagaraj
- CSIR-Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India
| |
Collapse
|
18
|
Sharma H, Nagaraj R. Human β-defensin 4 with non-native disulfide bridges exhibit antimicrobial activity. PLoS One 2015; 10:e0119525. [PMID: 25785690 PMCID: PMC4364940 DOI: 10.1371/journal.pone.0119525] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 01/14/2015] [Indexed: 01/05/2023] Open
Abstract
Human defensins play multiple roles in innate immunity including direct antimicrobial killing and immunomodulatory activity. They have three disulfide bridges which contribute to the stability of three anti-parallel β-strands. The exact role of disulfide bridges and canonical β-structure in the antimicrobial action is not yet fully understood. In this study, we have explored the antimicrobial activity of human β-defensin 4 (HBD4) analogs that differ in the number and connectivity of disulfide bridges. The cysteine framework was similar to the disulfide bridges present in μ-conotoxins, an unrelated class of peptide toxins. All the analogs possessed enhanced antimicrobial potency as compared to native HBD4. Among the analogs, the single disulfide bridged peptide showed maximum potency. However, there were no marked differences in the secondary structure of the analogs. Subtle variations were observed in the localization and membrane interaction of the analogs with bacteria and Candida albicans, suggesting a role for disulfide bridges in modulating their antimicrobial action. All analogs accumulated in the cytosol where they can bind to anionic molecules such as nucleic acids which would affect several cellular processes leading to cell death. Our study strongly suggests that native disulfide bridges or the canonical β-strands in defensins have not evolved for maximal activity but they play important roles in determining their antimicrobial potency.
Collapse
Affiliation(s)
- Himanshu Sharma
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
| | - Ramakrishnan Nagaraj
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
- * E-mail:
| |
Collapse
|
19
|
A hybrid cationic peptide composed of human β-defensin-1 and humanized θ-defensin sequences exhibits salt-resistant antimicrobial activity. Antimicrob Agents Chemother 2014; 59:217-25. [PMID: 25348533 DOI: 10.1128/aac.03901-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have designed a hybrid peptide by combining sequences of human β-defensin-1 (HBD-1) and θ-defensin, in an attempt to generate a molecule that combines the diversity in structure and biological activity of two different peptides to yield a promising therapeutic candidate. HBD-1 was chosen as it is a natural defensin of humans that is constitutively expressed, but its antibacterial activity is considerably impaired by elevated ionic strength. θ-Defensins are expressed in human bone marrow as a pseudogene and are homologous to rhesus monkey circular minidefensins. Retrocyclins are synthetic human θ-defensins. The cyclic nature of the θ-defensin peptides makes them salt resistant, nonhemolytic, and virtually noncytotoxic in vitro. However, a nonhuman circular molecule developed for clinical use would be less viable than a linear molecule. In this study, we have fused the C-terminal region of HBD-1 to the nonapeptide sequence of a synthetic retrocyclin. Cyclization was achieved by joining the terminal ends of the hybrid peptide by a disulfide bridge. The hybrid peptide with or without the disulfide bridge exhibited enhanced antimicrobial activity against both Gram-negative and Gram-positive bacteria as well as against fungi, including clinical bacterial isolates from eye infections. The peptide retained activity in the presence of NaCl and serum and was nonhemolytic in vitro. Thus, the hybrid peptide generated holds potential as a new class of antibiotics.
Collapse
|
20
|
Beck-Sickinger AG, Panitz N. Semi-synthesis of chemokines. Curr Opin Chem Biol 2014; 22:100-7. [DOI: 10.1016/j.cbpa.2014.09.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/19/2014] [Accepted: 09/19/2014] [Indexed: 01/04/2023]
|
21
|
Shahar OD, Gabizon R, Feine O, Alhadeff R, Ganoth A, Argaman L, Shimshoni E, Friedler A, Goldberg M. Acetylation of lysine 382 and phosphorylation of serine 392 in p53 modulate the interaction between p53 and MDC1 in vitro. PLoS One 2013; 8:e78472. [PMID: 24194938 PMCID: PMC3806821 DOI: 10.1371/journal.pone.0078472] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 09/12/2013] [Indexed: 11/18/2022] Open
Abstract
Occurrence of DNA damage in a cell activates the DNA damage response, a survival mechanism that ensures genomics stability. Two key members of the DNA damage response are the tumor suppressor p53, which is the most frequently mutated gene in cancers, and MDC1, which is a central adaptor that recruits many proteins to sites of DNA damage. Here we characterize the in vitro interaction between p53 and MDC1 and demonstrate that p53 and MDC1 directly interact. The p53-MDC1 interaction is mediated by the tandem BRCT domain of MDC1 and the C-terminal domain of p53. We further show that both acetylation of lysine 382 and phosphorylation of serine 392 in p53 enhance the interaction between p53 and MDC1. Additionally, we demonstrate that the p53-MDC1 interaction is augmented upon the induction of DNA damage in human cells. Our data suggests a new role for acetylation of lysine 382 and phosphorylation of serine 392 in p53 in the cellular stress response and offers the first evidence for an interaction involving MDC1 that is modulated by acetylation.
Collapse
Affiliation(s)
- Or David Shahar
- The Department of Genetics, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ronen Gabizon
- The Department of Organic Chemistry, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Oren Feine
- The Department of Genetics, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Raphael Alhadeff
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Assaf Ganoth
- The Interdisciplinary Center (IDC), Herzliya, Israel and Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa-Oranim, Tivon, Israel
| | - Liron Argaman
- The Department of Genetics, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Elee Shimshoni
- The Department of Genetics, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Assaf Friedler
- The Department of Organic Chemistry, the Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michal Goldberg
- The Department of Genetics, Alexander Silberman Institute of Life Sciences, the Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail:
| |
Collapse
|
22
|
Olli S, Rangaraj N, Nagaraj R. Effect of selectively introducing arginine and D-amino acids on the antimicrobial activity and salt sensitivity in analogs of human beta-defensins. PLoS One 2013; 8:e77031. [PMID: 24086767 PMCID: PMC3785448 DOI: 10.1371/journal.pone.0077031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 09/05/2013] [Indexed: 11/18/2022] Open
Abstract
We have examined the antimicrobial activity of C-terminal analogs of human β-defensins HBD-1and-3 wherein lysines have been selectively replaced by L- and D-arginines and L-isoleucine substituted with its D-enantiomer. The analogs exhibited antibacterial and antifungal activities. Physiological concentration of NaCl did not attenuate the activity of the peptides against Gram-negative bacteria considerably, while some attenuation of activity was observed against S. aureus. Variable attenuation of activity was observed in the presence of Ca2+ and Mg2+. Introduction of D-amino acids abrogated the need for a disulfide bridge for exhibiting activity. Confocal images of carboxyfluorescein (CF) labeled peptides indicated initial localization on the membrane and subsequent translocation into the cell. Analogs corresponding to cationic rich segments of human defensins substituted with L- and D-arginine, could be attractive candidates for development as future therapeutic drugs.
Collapse
Affiliation(s)
- Sudar Olli
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Nandini Rangaraj
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | |
Collapse
|
23
|
Sharma H, Nagaraj R. Antimicrobial activity of human β-defensin 4 analogs: insights into the role of disulfide linkages in modulating activity. Peptides 2012; 38:255-65. [PMID: 23000475 DOI: 10.1016/j.peptides.2012.08.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 08/21/2012] [Accepted: 08/21/2012] [Indexed: 02/08/2023]
Abstract
Human β-defensins (HBDs) are cationic antimicrobial peptides that are components of the innate immune system. They are characterized by three disulfide bridges. However, the number of cationic residues as well as the presence of lysine and arginine residues vary. In HBD4, the cationic residues occur predominantly in the N-terminal segment, unlike in HBD1-3. We have examined the antimicrobial activity of peptides spanning the N- and C-terminal segments of HBD4. We have introduced one, two and three disulfide bridges in the peptides corresponding to the N-terminal segments. Peptides corresponding to the N-terminal segment had identical sequences and variation was only in the number and spacing of cysteines and disulfide bridges. Antimicrobial activity to varying extents was observed for all the peptides. When two disulfide bridges were present, decrease in antimicrobial potency as well as sensitivity of activity to salt was observed. Enhanced antimicrobial activity was observed when three disulfide bridges were present. The antimicrobial potency was similar to HBD4 except against Escherichia coli and was attenuated in the presence of salt. While the presence of three disulfide bridges did not constrain the peptide to a rigid β-sheet, the activity was considerably more as compared to the peptides with one or two disulfide bridges. The peptides enter bacterial and fungal cells rapidly without membrane permeabilization and appear to exert their activity inside the cells rather than at the membrane.
Collapse
Affiliation(s)
- Himanshu Sharma
- CSIR - Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007, India
| | | |
Collapse
|
24
|
Gabizon R, Brandt T, Sukenik S, Lahav N, Lebendiker M, Shalev DE, Veprintsev D, Friedler A. Specific recognition of p53 tetramers by peptides derived from p53 interacting proteins. PLoS One 2012; 7:e38060. [PMID: 22693587 PMCID: PMC3365014 DOI: 10.1371/journal.pone.0038060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 05/02/2012] [Indexed: 11/25/2022] Open
Abstract
Oligomerization plays a major role in regulating the activity of many proteins, and in modulating their interactions. p53 is a homotetrameric transcription factor that has a pivotal role in tumor suppression. Its tetramerization domain is contained within its C-terminal domain, which is a site for numerous protein-protein interactions. Those can either depend on or regulate p53 oligomerization. Here we screened an array of peptides derived from proteins known to bind the tetrameric p53 C-terminal domain (p53CTD) and identified ten binding peptides. We quantitatively characterized their binding to p53CTD using fluorescence anisotropy. The peptides bound tetrameric p53CTD with micromolar affinities. Despite the high charge of the binding peptides, electrostatics contributed only mildly to the interactions. NMR studies indicated that the peptides bound p53CTD at defined sites. The most significant chemical shift deviations were observed for the peptides WS100B(81-92), which bound directly to the p53 tetramerization domain, and PKCα(281-295), which stabilized p53CTD in circular dichroism thermal denaturation studies. Using analytical ultracentrifugation, we found that several of the peptides bound preferentially to p53 tetramers. Our results indicate that the protein-protein interactions of p53 are dependent on the oligomerization state of p53. We conclude that peptides may be used to regulate the oligomerization of p53.
Collapse
Affiliation(s)
- Ronen Gabizon
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tobias Brandt
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Shahar Sukenik
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Noa Lahav
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mario Lebendiker
- The Wolfson Centre for Applied Structural Biology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Deborah E. Shalev
- The Wolfson Centre for Applied Structural Biology, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dmitry Veprintsev
- MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen, Switzerland
- Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Assaf Friedler
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
25
|
Slaninová J, Mlsová V, Kroupová H, Alán L, Tůmová T, Monincová L, Borovičková L, Fučík V, Ceřovský V. Toxicity study of antimicrobial peptides from wild bee venom and their analogs toward mammalian normal and cancer cells. Peptides 2012; 33:18-26. [PMID: 22100226 DOI: 10.1016/j.peptides.2011.11.002] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 11/02/2011] [Accepted: 11/02/2011] [Indexed: 12/22/2022]
Abstract
Recently, we have isolated and characterized remarkable antimicrobial peptides (AMPs) from the venom reservoirs of wild bees. These peptides (melectin, lasioglossins, halictines and macropin) and their analogs display high antimicrobial activity against Gram-positive and -negative bacteria, antifungal activity and low or moderate hemolytic activity. Here we describe cytotoxicity of the above-mentioned AMPs and some of their analogs toward two normal cell lines (human umbilical vein endothelial cells, HUVEC, and rat intestinal epithelial cells, IEC) and three cancer cell lines (HeLa S3, CRC SW 480 and CCRF-CEM T). HeLa S3 cells were the most sensitive ones (concentration causing 50% cell death in the case of the most toxic analogs was 2.5-10 μM) followed by CEM cells. For the other cell lines to be killed, the concentrations had to be four to twenty times higher. These results bring promising outlooks of finding medically applicable drugs on the basis of AMPs. Experiments using fluorescently labeled lasioglossin III (Fl-VNWKKILGKIIKVVK-NH(2)) as a tracer confirmed that the peptides entered the mammalian cells in higher quantities only after they reached the toxic concentration. After entering the cells, their concentration was the highest in the vicinity of the nucleus, in the nucleolus and in granules which were situated at very similar places as mitochondria. Experiments performed using cells with tetramethylrhodamine labeled mitochondria showed that mitochondria were fragmented and lost their membrane potential in parallel with the entrance of the peptides into the cell and the disturbance of the cell membrane.
Collapse
Affiliation(s)
- Jiřina Slaninová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic.
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Bellmann-Sickert K, Beck-Sickinger AG. Palmitoylated SDF1α shows increased resistance against proteolytic degradation in liver homogenates. ChemMedChem 2011; 6:193-200. [PMID: 21140394 DOI: 10.1002/cmdc.201000403] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The chemokine stromal cell-derived factor-1α (SDF1α) is strongly involved in organogenesis, as well as inflammation and tissue repair, and acts by attracting different kinds of stem and progenitor cells. Therefore, it constitutes an interesting compound for drug development in regenerative medicine. However, it is prone to inactivation by proteolytic cleavage in human serum. Accordingly, it has to be stabilized against enzymatic degradation for any therapeutic application. We synthesized a palmitoylated SDF1α analogue by native chemical ligation. Both the N-terminal thioester and the C-terminal palmitoylated fragment were prepared by solid-phase peptide synthesis. The activity of the refolded and pure compound was determined by an inositol phosphate turnover assay and revealed no loss in receptor activation. Additionally, resistance to proteolytic degradation was investigated in porcine liver homogenates and showed a near sevenfold increased half time. This study is a proof of principle approach for the lipidation of SDF1α and provides a basis for further engineering of the chemokine in order to increase its therapeutic value.
Collapse
|
27
|
Abstract
AbstractAs the occurrence of Candida species infections increases, so does resistance against commonly-used antifungal agents. It is therefore necessary to look for new antifungal drugs. This study investigated the antifungal activity of recently isolated, synthesized and characterized antimicrobial α-helical amphipathic peptides (12–18 amino acids long) from the venom of hymenoptera (melectin, lasioglossins I, II, and III, halictines I and II) as well as a whole series of synthetic analogs. The minimal inhibitory concentrations (MICs) against different Candida species (C. albicans, C. krusei, C. glabrata, C. tropicalis and C. parapsilosis) of the natural peptides amounted to 4–20 µM (7–40 mg/l). The most active were the synthetic analog all-D-lasioglossin III and lasioglossin III analog KNWKK-Aib-LGK-Aib-IK-Aib-VK-NH2. As shown using a) colony forming unit determination on agar plates, b) the efflux of the dye from rhodamine 6B-loaded cells, c) propidium iodide and DAPI staining, and d) fluorescently labeled antimicrobial peptide (5(6)-carboxyfluorescein lasioglossin-III), the killing of fungi by the peptides studied occurs within minutes and might be accompanied by a disturbance of all membrane barriers. The peptides represent a promising lead for the development of new, effective antifungal drugs.
Collapse
|
28
|
Bellmann-Sickert K, Elling CE, Madsen AN, Little PB, Lundgren K, Gerlach LO, Bergmann R, Holst B, Schwartz TW, Beck-Sickinger AG. Long-Acting Lipidated Analogue of Human Pancreatic Polypeptide Is Slowly Released into Circulation. J Med Chem 2011; 54:2658-67. [DOI: 10.1021/jm101357e] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Kathrin Bellmann-Sickert
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Leipzig University, Brüderstrasse 34, D-04103 Leipzig, Germany
| | | | - Andreas N. Madsen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, The University of Copenhagen, The Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | | | | | | | - Ralf Bergmann
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmacy, Bautzner Landstrasse 400, D-01328 Dresden, Germany
| | - Birgitte Holst
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, The University of Copenhagen, The Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Thue W. Schwartz
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, The University of Copenhagen, The Panum Institute, Blegdamsvej 3, DK-2200 Copenhagen, Denmark
| | - Annette G. Beck-Sickinger
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Leipzig University, Brüderstrasse 34, D-04103 Leipzig, Germany
| |
Collapse
|
29
|
Bellmann-Sickert K, Baumann L, Beck-Sickinger AG. Selective labelling of stromal cell-derived factor 1α with carboxyfluorescein to study receptor internalisation. J Pept Sci 2011; 16:568-74. [PMID: 20862724 DOI: 10.1002/psc.1228] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
SDF1α plays an important role in the regeneration of injured tissue after ischemia or stroke by inducing the migration of progenitor cells. In order to study the function of this therapeutically relevant chemokine site-specific protein labelling is of great interest. However, modification of SDF1α is complicated because of its complex tertiary structure. Here, we describe the first site-specific fluorescent modification of SDF1α by EPL. We recombinantly expressed SDF1α (1-49) by intein-mediated protein expression. The C-terminal peptide SDF1α (50-68) was synthesised by SPPS and selectively labelled with carboxyfluorescein at Lys(56). In a cell migration assay, M-[K(56)(CF)]SDF1α showed a clear potency to induce chemotaxis of human T-cell leukaemia cells. Microscopic analysis on HEK293 cells transfected with the CXCR4 revealed specific binding of the fluorescent ligand. Furthermore, receptor-induced internalisation of the ligand could be visualised. These results show that site-specific modification of SDF1α yields in a biologically functional molecule that allows the characterisation of CXCR4 production of cells on a molecular level.
Collapse
|
30
|
Abstract
IMPORTANCE OF THE FIELD Fluorescence polarization (FP) is a homogeneous method that allows rapid and quantitative analysis of diverse molecular interactions and enzyme activities. This technique has been widely utilized in clinical and biomedical settings, including the diagnosis of certain diseases and monitoring therapeutic drug levels in body fluids. Recent developments in the field have been symbolized by the facile adoption of FP in high-throughput screening and small molecule drug discovery of an increasing range of target classes. AREAS COVERED IN THIS REVIEW The article provides a brief overview of the theoretical foundation of FP, followed by updates on recent advancements in its application for various drug target classes, including GPCRs, enzymes and protein-protein interactions. The strengths and weaknesses of this method, practical considerations in assay design, novel applications and future directions are also discussed. WHAT THE READER WILL GAIN The reader is informed of the most recent advancements and future directions of FP application to small molecule screening. TAKE HOME MESSAGE In addition to its continued utilization in high-throughput screening, FP has expanded into new disease and target areas and has been marked by increased use of labeled small molecule ligands for receptor-binding studies.
Collapse
Affiliation(s)
- Wendy A. Lea
- NIH Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3370, U.S.A
| | - Anton Simeonov
- NIH Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3370, U.S.A
| |
Collapse
|
31
|
Khan I, Zwanziger D, Böhme I, Javed M, Naseer H, Hyder S, Beck-Sickinger A. Breast-Cancer Diagnosis by Neuropeptide Y Analogues: From Synthesis to Clinical Application. Angew Chem Int Ed Engl 2010; 49:1155-8. [DOI: 10.1002/anie.200905008] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
32
|
Khan I, Zwanziger D, Böhme I, Javed M, Naseer H, Hyder S, Beck-Sickinger A. Neuropeptid-Y-Analoga zur Brustkrebsdiagnostik: von der Synthese zur klinischen Anwendung. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.200905008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
33
|
Reindl W, Gräber M, Strebhardt K, Berg T. Development of high-throughput assays based on fluorescence polarization for inhibitors of the polo-box domains of polo-like kinases 2 and 3. Anal Biochem 2009; 395:189-94. [PMID: 19716361 DOI: 10.1016/j.ab.2009.08.031] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 08/20/2009] [Accepted: 08/22/2009] [Indexed: 01/12/2023]
Abstract
The serine/threonine kinases Plk1, Plk2, and Plk3 harbor a protein-protein interaction domain dubbed polo-box domain (PBD). Recently, the inhibition of the PBD of the cancer target Plk1 has been successfully explored as an alternative to the inhibition of the kinase by ATP-competitive ligands. However, because the PBDs of Plk1, Plk2, and Plk3 have very similar optimal binding motifs, absolute specificity for the PBD of Plk1 over the PBDs of Plk2 and Plk3 may also represent a big challenge for a small molecule. To aid in the activity profiling of Plk PBD inhibitors, and to identify selective small molecules that will reveal the cellular consequences of inhibiting the PBDs of Plk2 and Plk3, we have developed high-throughput assays based on fluorescence polarization against the PBDs of Plk2 and Plk3. The assays are stable with regard to time and 10% dimethyl sulfoxide and have Z' values > or = 0.7, making them well-suited for high-throughput screening. Moreover, our data provide insights into the binding preferences of the PBDs of Plk2 and Plk3.
Collapse
Affiliation(s)
- Wolfgang Reindl
- Department of Molecular Biology, Max Planck Institute of Biochemistry, and Center for Integrated Protein Science Munich, 82152 Martinsried, Germany
| | | | | | | |
Collapse
|
34
|
Ronen D, Rosenberg MM, Shalev DE, Rosenberg M, Rotem S, Friedler A, Ravid S. The positively charged region of the myosin IIC non-helical tailpiece promotes filament assembly. J Biol Chem 2009; 285:7079-86. [PMID: 19959848 DOI: 10.1074/jbc.m109.049221] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The motor protein, non-muscle myosin II (NMII), must undergo dynamic oligomerization into filaments to participate in cellular processes such as cell migration and cytokinesis. A small non-helical region at the tail of the long coiled-coil region (tailpiece) is a common feature of all dynamically assembling myosin II proteins. In this study, we investigated the role of the tailpiece in NMII-C self-assembly. We show that the tailpiece is natively unfolded, as seen by circular dichroism and NMR experiments, and is divided into two regions of opposite charge. The positively charged region (Tailpiece(1946-1967)) starts at residue 1946 and is extended by seven amino acids at its N terminus from the traditional coiled-coil ending proline (Tailpiece(1953-1967)). Pull-down and sedimentation assays showed that the positive Tailpiece(1946-1967) binds to assembly incompetent NMII-C fragments inducing filament assembly. The negative region, residues 1968-2000, is responsible for NMII paracrystal morphology as determined by chimeras in which the negative region was swapped between the NMII isoforms. Mixing the positive and negative peptides had no effect on the ability of the positive peptide to bind and induce filament assembly. This study provides molecular insight into the role of the structurally disordered tailpiece of NMII-C in shifting the oligomeric equilibrium of NMII-C toward filament assembly and determining its morphology.
Collapse
Affiliation(s)
- Daniel Ronen
- Department of Biochemistry and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | | | | | | | | | | | | |
Collapse
|
35
|
Moerke NJ. Fluorescence Polarization (FP) Assays for Monitoring Peptide‐Protein or Nucleic Acid‐Protein Binding. ACTA ACUST UNITED AC 2009; 1:1-15. [DOI: 10.1002/9780470559277.ch090102] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
36
|
Maes M, Levin A, Hayouka Z, Shalev DE, Loyter A, Friedler A. Peptide inhibitors of HIV-1 integrase: from mechanistic studies to improved lead compounds. Bioorg Med Chem 2009; 17:7635-42. [PMID: 19850483 DOI: 10.1016/j.bmc.2009.09.053] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 09/22/2009] [Accepted: 09/30/2009] [Indexed: 12/23/2022]
Abstract
The HIV-1 integrase enzyme (IN) catalyzes integration of viral DNA into the host genome. We previously developed peptides that inhibit IN in vitro and HIV-1 replication in cells. Here we present the design, synthesis and evaluation of several derivatives of one of these inhibitory peptides, the 20-mer IN1. The peptide corresponding to the N-terminal half of IN1 (IN1 1-10) was easier to synthesize and much more soluble than the 20-mer IN1. IN1 1-10 bound IN with improved affinity and inhibited IN activity as well as HIV replication and integration in infected cells. While IN1 bound the IN tetramer, its shorter derivatives bound dimeric IN. Mapping the peptide binding sites in IN provided a model that explains this difference. We conclude that IN1 1-10 is an improved lead compound for further development of IN inhibitors.
Collapse
Affiliation(s)
- Michal Maes
- Institute of Chemistry, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel
| | | | | | | | | | | |
Collapse
|
37
|
Deceuninck A, Madder A. From DNA cross-linking to peptide labeling: on the versatility of the furan-oxidation–conjugation strategy. Chem Commun (Camb) 2009:340-2. [DOI: 10.1039/b817447d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
38
|
Uryga-Polowy V, Kosslick D, Freund C, Rademann J. Resin-bound aminofluorescein for C-terminal labeling of peptides: high-affinity polarization probes binding to polyproline-specific GYF domains. Chembiochem 2008; 9:2452-62. [PMID: 18803191 DOI: 10.1002/cbic.200800329] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A polymer support for the solid-phase synthesis of C-terminally labeled carboxylic acids has been developed. Fluorophore-labeled peptides were constructed directly on the amino group of resin-bound aminofluorescein. Fmoc-protected aminofluorescein was coupled onto tritylpolystyrene, and the free phenolic hydroxyl positions of the fluorescein were blocked with suitable protecting groups. The mode of attachment was analyzed and found to be selective for the phenoxy ether linkage. The conditions for peptide synthesis on the labeling resin were investigated, and a small library of C-terminally labeled peptides was prepared. The fluorescence quantum yields of C-terminally labeled peptides were determined and indicated the suitability of the compounds for imaging and binding experiments. The obtained peptides were therefore investigated as fluorescence polarization probes. Two different proline-rich binding domains of the GYF family-CD2BP2 and PERQ2-were targeted by peptides labeled either C- or N-terminally. Reversible binding constants were determined by fluorescence polarization measurements and were verified by competition experiments with the corresponding unlabeled peptide. As a second control, the binding constants were measured by NMR titration experiments, recording the HSQC NMR spectra of (15)N-labeled proteins in the presence of the peptide polarization probes. Ligands with higher affinities than all others known previously were identified for both GYF domains. The competition assay with the developed fluorescent probe has a high statistical reliability and can thus be used for screening of GYF domain inhibitors.
Collapse
Affiliation(s)
- Viviane Uryga-Polowy
- Department of Medicinal Chemistry, Leibniz Institute for Molecular Pharmacology FMP, Berlin, Germany
| | | | | | | |
Collapse
|
39
|
Casanovas J, Jacquemin D, Perpète EA, Alemán C. Fluorescein isothiocyanate: Molecular characterization by theoretical calculations. Chem Phys 2008. [DOI: 10.1016/j.chemphys.2008.10.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
40
|
Antifungal activities of human beta-defensins HBD-1 to HBD-3 and their C-terminal analogs Phd1 to Phd3. Antimicrob Agents Chemother 2008; 53:256-60. [PMID: 18809937 DOI: 10.1128/aac.00470-08] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The activities of defensins HBD-1, HBD-2, and HBD-3 and their C-terminal analogs Phd1, Phd2, and Phd3 against Candida albicans were investigated. Phd1 to Phd3 showed lower-level activities than HBD-1 to HBD-3, although metabolic inhibitors did not render Phd1 to Phd3 inactive. Their activities were also less salt sensitive than those of HBD-1 to HBD-3. Confocal microscope images indicated that the initial site of action was the fungal membrane.
Collapse
|
41
|
Zwanziger D, Khan IU, Neundorf I, Sieger S, Lehmann L, Friebe M, Dinkelborg L, Beck-Sickinger AG. Novel Chemically Modified Analogues of Neuropeptide Y for Tumor Targeting. Bioconjug Chem 2008; 19:1430-8. [DOI: 10.1021/bc7004297] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Denise Zwanziger
- Institute of Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany, and Bayer Schering Pharma, Global Drug Discovery, Berlin, Germany
| | - Irfan Ullah Khan
- Institute of Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany, and Bayer Schering Pharma, Global Drug Discovery, Berlin, Germany
| | - Ines Neundorf
- Institute of Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany, and Bayer Schering Pharma, Global Drug Discovery, Berlin, Germany
| | - Stephanie Sieger
- Institute of Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany, and Bayer Schering Pharma, Global Drug Discovery, Berlin, Germany
| | - Lutz Lehmann
- Institute of Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany, and Bayer Schering Pharma, Global Drug Discovery, Berlin, Germany
| | - Matthias Friebe
- Institute of Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany, and Bayer Schering Pharma, Global Drug Discovery, Berlin, Germany
| | - Ludger Dinkelborg
- Institute of Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany, and Bayer Schering Pharma, Global Drug Discovery, Berlin, Germany
| | - Annette G. Beck-Sickinger
- Institute of Biochemistry, Leipzig University, Brüderstr. 34, 04103 Leipzig, Germany, and Bayer Schering Pharma, Global Drug Discovery, Berlin, Germany
| |
Collapse
|
42
|
Müller J, Schust J, Berg T. A high-throughput assay for signal transducer and activator of transcription 5b based on fluorescence polarization. Anal Biochem 2008; 375:249-54. [DOI: 10.1016/j.ab.2008.01.017] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 01/09/2008] [Accepted: 01/14/2008] [Indexed: 10/22/2022]
|
43
|
Aschi M, D’Archivio AA, Fontana A, Formiglio A. Physicochemical Properties of Fluorescent Probes: Experimental and Computational Determination of the Overlapping pKa Values of Carboxyfluorescein. J Org Chem 2008; 73:3411-7. [DOI: 10.1021/jo800036z] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Massimiliano Aschi
- Dipartimento di Chimica, Ingegneria Chimica e Materiali, Università degli Studi de L’Aquila, Via Vetoio (Coppito II), 67010 Coppito, L’Aquila, Italy, and Dipartimento di Scienze del Farmaco, Università “G. d’Annunzio”, Via dei Vestini, 66013 Chieti, Italy
| | - Angelo A. D’Archivio
- Dipartimento di Chimica, Ingegneria Chimica e Materiali, Università degli Studi de L’Aquila, Via Vetoio (Coppito II), 67010 Coppito, L’Aquila, Italy, and Dipartimento di Scienze del Farmaco, Università “G. d’Annunzio”, Via dei Vestini, 66013 Chieti, Italy
| | - Antonella Fontana
- Dipartimento di Chimica, Ingegneria Chimica e Materiali, Università degli Studi de L’Aquila, Via Vetoio (Coppito II), 67010 Coppito, L’Aquila, Italy, and Dipartimento di Scienze del Farmaco, Università “G. d’Annunzio”, Via dei Vestini, 66013 Chieti, Italy
| | - Alessandra Formiglio
- Dipartimento di Chimica, Ingegneria Chimica e Materiali, Università degli Studi de L’Aquila, Via Vetoio (Coppito II), 67010 Coppito, L’Aquila, Italy, and Dipartimento di Scienze del Farmaco, Università “G. d’Annunzio”, Via dei Vestini, 66013 Chieti, Italy
| |
Collapse
|
44
|
Rennert R, Neundorf I, Beck-Sickinger AG. Calcitonin-derived peptide carriers: mechanisms and application. Adv Drug Deliv Rev 2008; 60:485-98. [PMID: 18160173 DOI: 10.1016/j.addr.2007.09.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2007] [Accepted: 09/04/2007] [Indexed: 01/16/2023]
Abstract
Among the family of the so-called cell-penetrating peptides (CPP) sequences derived from the native peptide hormone human calcitonin (hCT) have recently proven to translocate different bioactive molecules across cellular membranes. Herein, we give an extensive summary of the development of hCT-derived carrier peptides, beginning with the therapeutic nasal administration of full-length hCT. Hence, N-terminally truncated hCT fragments were investigated and subsequently optimised to extend their field of application. The latest generation of hCT-derived carrier peptides are highly effective, branched peptides. The current state of the art is reviewed concerning the structural requirements, mechanistic assumptions and metabolic features of these peptides as well as experiments proving their excellent carrier potential.
Collapse
Affiliation(s)
- Robert Rennert
- Institute of Biochemistry, Faculty of Bioscience, Pharmacy and Psychology, Leipzig University, Brüderstr. 34, D-04103 Leipzig, Germany
| | | | | |
Collapse
|
45
|
Katritzky AR, Yoshioka M, Narindoshvili T, Chung A, Johnson JV. Fluorescent labeling of peptides on solid phase. Org Biomol Chem 2008; 6:4582-6. [DOI: 10.1039/b811693h] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
46
|
Khan IU, Reppich R, Beck-Sickinger AG. Identification of neuropeptide Y cleavage products in human blood to improve metabolic stability. Biopolymers 2007; 88:182-9. [PMID: 17206650 DOI: 10.1002/bip.20666] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Regulatory, receptor-binding peptides are considered as the agents of choice for diagnostic imaging and therapy of cancers, because their receptors are overexpressed in various human cancer cells. It has been recently indicated that there is a putative role of NPY in breast tumors. The expression of the two best-investigated NPY receptor subtypes, Y1 and Y2, in breast tissue shows predominant occurrence of the Y1 receptor subtype in tumors, whereas Y2 receptors are found in nonproliferative tissue. To investigate the usefulness of NPY analogs for tumor diagnosis and therapy, we investigated the metabolic stability of receptor-selective NPY analogs in human blood plasma. NPY analogs were synthesized by Fmoc/t-Bu solid-phase strategy. Prior to the cleavage of peptides from the resin, they were labeled with 5(6)-carboxyfluorescein (CF) either at the N-terminus or at the side chain of Lys4. For the metabolic stability study, the digestion of peptides was monitored by HPLC and the cleavage products were identified by MALDI-ToF mass spectrometry. The data showed that full-length [Phe7, Pro34]NPY analogs, which show high binding affinity to Y1 receptors are enzymatically more stable than centrally truncated analogs, which show high binding affinity to Y2 receptors. Furthermore, the N-terminally CF-labeled Y1 and Y2 receptor-selective peptides were found to be enzymatically more resistant than their counterparts containing the CF label at Lys4 side chain.
Collapse
Affiliation(s)
- Irfan Ullah Khan
- Institute of Biochemistry, University of Leipzig, Bruederstr 34, 04103 Leipzig, Germany
| | | | | |
Collapse
|
47
|
Dizhe EB, Ignatovich IA, Burov SV, Pohvoscheva AV, Akifiev BN, Efremov AM, Perevozchikov AP, Orlov SV. Complexes of DNA with cationic peptides: Conditions of formation and factors effecting internalization by mammalian cells. BIOCHEMISTRY (MOSCOW) 2006; 71:1350-6. [PMID: 17223788 DOI: 10.1134/s0006297906120108] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This work was devoted to the study of conditions of the formation of DNA/K8 complex and analysis of factors effecting the entry of DNA/K8 complex into mammalian cells in comparison with DNA complexes with arginine-rich fragment (47-57) of human immunodeficiency virus (type 1) transcription factor Tat (Tat peptide). The stoichiometry of positively charged DNA/K8 complexes has been studied for the first time. Non-cooperative character of DNA-K8 interaction was revealed. It has been shown that along with the positive charge of such complexes, the presence of an excess of free K8 peptide in the culture medium is a necessary condition for maximal efficiency of cell transfection with DNA/K8 complexes. A stimulatory effect of free K8 peptide on the efficiency of mammalian cell transfection by DNA/K8 complexes is likely to be mediated by the interactions of cationic peptide K8 with negatively charged proteoglycans on the cell surface, which leads to protection of DNA/K8 complexes from disruption by cellular heparan sulfates. However, the protective role of free cationic peptides depends not only on their positive charge, but also on the primary structure of the peptide. In contrast with the results obtained for DNA complexes with molecular conjugates based on poly-L-lysine, the aggregation of DNA/K8 complexes leads to a significant increase in the expression of transferred gene.
Collapse
Affiliation(s)
- E B Dizhe
- Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, 197376, Russia
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Xia J, Siegel M, Bergseng E, Sollid LM, Khosla C. Inhibition of HLA-DQ2-mediated antigen presentation by analogues of a high affinity 33-residue peptide from alpha2-gliadin. J Am Chem Soc 2006; 128:1859-67. [PMID: 16464085 PMCID: PMC2597451 DOI: 10.1021/ja056423o] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Human leukocyte antigen DQ2 is a class II major histocompatibility complex protein that plays a critical role in the pathogenesis of Celiac Sprue by binding to epitopes derived from dietary gluten and triggering the inflammatory response of disease-specific T cells. Inhibition of DQ2-mediated antigen presentation in the small intestinal mucosa of Celiac Sprue patients therefore represents a potentially attractive mode of therapy for this widespread but unmet medical need. Starting from a pro-inflammatory, proteolytically resistant, 33-residue peptide, LQLQPFPQPELPYPQPELPYPQPELPYPQPQPF, we embarked upon a systematic effort to dissect the relationships between peptide structure and DQ2 affinity and to translate these insights into prototypical DQ2 blocking agents. Three structural determinants within the first 20 residues of this 33-mer peptide, including a PQPELPYPQ epitope, its N-terminal flanking sequence, and a downstream Glu residue, were found to be important for DQ2 binding. Guided by the X-ray crystal structure of DQ2, the L11 and L18 residues in the truncated 20-mer analogue were replaced with sterically bulky groups so as to retain high DQ2 affinity but abrogate T cell recognition. A dimeric ligand, synthesized by regiospecific coupling of the 20-mer peptide with a bifunctional linker, was identified as an especially potent DQ2 binding agent. Two such ligands were able to attenuate the proliferation of disease-specific T cell lines in response to gluten antigens and, therefore, represent prototypical examples of pharmacologically suitable DQ2 blocking agents for the potential treatment of Celiac Sprue.
Collapse
Affiliation(s)
- Jiang Xia
- Department of Chemistry, Stanford University, Stanford, USA
| | - Matthew Siegel
- Department of Chemical Engineering, Stanford University, Stanford, USA
| | - Elin Bergseng
- Institute of Immunology, University of Oslo, Rikshospitalet University Hospital, Oslo, Norway
| | - Ludvig M. Sollid
- Institute of Immunology, University of Oslo, Rikshospitalet University Hospital, Oslo, Norway
| | - Chaitan Khosla
- Department of Chemistry, Stanford University, Stanford, USA
- Department of Chemical Engineering, Stanford University, Stanford, USA
- Department of Biochemistry, Stanford University, Stanford, USA
| |
Collapse
|
49
|
Lokesh GL, Rachamallu A, Kumar GDK, Natarajan A. High-throughput fluorescence polarization assay to identify small molecule inhibitors of BRCT domains of breast cancer gene 1. Anal Biochem 2006; 352:135-41. [PMID: 16500609 DOI: 10.1016/j.ab.2006.01.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 01/11/2006] [Accepted: 01/11/2006] [Indexed: 11/18/2022]
Abstract
The C-terminus region of the 1863 residue early onset of breast cancer gene 1 (BRCA1) nuclear protein contains a tandem globular carboxy terminus domain termed BRCT. The BRCT repeats in BRCA1 are phosphoserine- and/or phosphothreonine-specific binding modules. The interaction of the BRCT(BRCA1) domains with phosphorylated BRCA1-associated carboxyl terminal helicase (BACH1) is cell cycle regulated and is essential for DNA damage-induced checkpoint control during the transition from the G(2) phase to the M phase of the cell cycle. Development of a competitive, homogeneous, high-throughput fluorescence polarization (FP) assay to identify small molecule inhibitors of BRCT(BRCA1)-BACH1 interaction is reported here. The FP assay was used for measuring binding affinities and inhibition constants of BACH1 peptides and small molecule inhibitors of BRCT(BRCA1) domains, respectively. A fluorescently labeled wild-type BACH1 decapeptide (BDP1) containing the critical phosphoserine, a phenylalanine at (P+3), and a GST-BRCT fusion protein were used to establish the FP assay. BDP1 has a dissociation constant (K(d)) of 1.58+/-0.01microM and a dynamic range (DeltamP) of 164.9+/-1.9. The assay tolerates 20% dimethyl sulfoxide, which enables screening poorly soluble compounds. Under optimized conditions, a Z' factor of 0.87 was achieved in a 384-well format for high-throughput screening.
Collapse
Affiliation(s)
- G L Lokesh
- Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | | | | | | |
Collapse
|
50
|
Simmons DP, Peach ML, Friedman JR, Green MMB, Nicklaus MC, De Luca LM. Evidence that sequence homologous region in LRAT-like proteins possesses anti-proliferative activity and DNA binding properties: translational implications and mechanism of action. Carcinogenesis 2005; 27:693-707. [PMID: 16234259 DOI: 10.1093/carcin/bgi235] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
LRAT (lecithin:retinol acyltransferase), an enzyme whose levels are modulated during malignant conversion, has been reported as the founder member of a new LRAT-like family that includes tumor suppressors TIG-3(1-164) and Ha-Rev107(1-162). The mechanisms that link these three proteins to carcinogenesis as well as the significance of a reported shared sequence homologous region remain unclear. This begs the question if the tumor suppressors possess enzyme properties and/or if the LRAT enzyme possesses tumor suppressor properties. We use the reported homologous region as a first approach to address the question from the perspective that all three proteins can possess tumor suppressor properties. We postulated that the homologous sequence harbors an anti-proliferation domain within the full-length proteins and that dodecapeptides of this sequence possess anti-proliferative activity. We report that H-TIG-3(111-123), H-Ha-Rev107-1(111-123) and H-LRAT160-171:C168L exhibited in vitro growth inhibitory activity in a human cutaneous melanoma (HCM) model and affected tumor growth in a nude mouse model. Further, in peptide-sensitive HCM cells, these peptides crossed the plasma membrane and localized to the nucleus, where they could bind and activate promoters of transcription factors involved in G1-->S transition. Moreover, peptide-induced abrogation of cyclin dependent kinase-2 expression was concomitant with sub-cellular re-distribution of cyclins E and A. Indeed, the sequence homologous region within each full-length wild-type protein as well as the growth inhibitory peptides can form alpha helices, a likely configuration for binding to DNA. This is the first report that this sequence homologous region (AA111-123) within these LRAT-like proteins harbors an anti-proliferative domain with DNA binding properties. Sequences from this sequence homologous region can be used as templates for anti-tumor drug design and as probes to investigate disease-related mechanisms and structure-activity relationships of the full-length proteins, TIG-3(1-164), Ha-Rev107(1-162) and LRAT160-171.
Collapse
Affiliation(s)
- Denise Perry Simmons
- Laboratory of Cellular Carcinogenesis and Tumor Promotion, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | | | | | | | | | | |
Collapse
|