101
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Zhan X, Stoy H, Kaoud TS, Perry NA, Chen Q, Perez A, Els-Heindl S, Slagis JV, Iverson TM, Beck-Sickinger AG, Gurevich EV, Dalby KN, Gurevich VV. Peptide mini-scaffold facilitates JNK3 activation in cells. Sci Rep 2016; 6:21025. [PMID: 26868142 PMCID: PMC4751492 DOI: 10.1038/srep21025] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 01/15/2016] [Indexed: 12/19/2022] Open
Abstract
Three-kinase mitogen-activated protein kinase (MAPK) signaling cascades are present in virtually all eukaryotic cells. MAPK cascades are organized by scaffold proteins, which assemble cognate kinases into productive signaling complexes. Arrestin-3 facilitates JNK activation in cells, and a short 25-residue arrestin-3 peptide was identified as the critical JNK3-binding element. Here we demonstrate that this peptide also binds MKK4, MKK7, and ASK1, which are upstream JNK3-activating kinases. This peptide is sufficient to enhance JNK3 activity in cells. A homologous arrestin-2 peptide, which differs only in four positions, binds MKK4, but not MKK7 or JNK3, and is ineffective in cells at enhancing activation of JNK3. The arrestin-3 peptide is the smallest MAPK scaffold known. This peptide or its mimics can regulate MAPKs, affecting cellular decisions to live or die.
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102
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Hu J, Stern M, Gimenez LE, Wanka L, Zhu L, Rossi M, Meister J, Inoue A, Beck-Sickinger AG, Gurevich VV, Wess J. A G Protein-biased Designer G Protein-coupled Receptor Useful for Studying the Physiological Relevance of Gq/11-dependent Signaling Pathways. J Biol Chem 2016; 291:7809-20. [PMID: 26851281 DOI: 10.1074/jbc.m115.702282] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Indexed: 01/14/2023] Open
Abstract
Designerreceptorsexclusivelyactivated by adesignerdrug (DREADDs) are clozapine-N-oxide-sensitive designer G protein-coupled receptors (GPCRs) that have emerged as powerful novel chemogenetic tools to study the physiological relevance of GPCR signaling pathways in specific cell types or tissues. Like endogenous GPCRs, clozapine-N-oxide-activated DREADDs do not only activate heterotrimeric G proteins but can also trigger β-arrestin-dependent (G protein-independent) signaling. To dissect the relative physiological relevance of G protein-mediatedversusβ-arrestin-mediated signaling in different cell types or physiological processes, the availability of G protein- and β-arrestin-biased DREADDs would be highly desirable. In this study, we report the development of a mutationally modified version of a non-biased DREADD derived from the M3muscarinic receptor that can activate Gq/11with high efficacy but lacks the ability to interact with β-arrestins. We also demonstrate that this novel DREADD is activein vivoand that cell type-selective expression of this new designer receptor can provide novel insights into the physiological roles of G protein (Gq/11)-dependentversusβ-arrestin-dependent signaling in hepatocytes. Thus, this novel Gq/11-biased DREADD represents a powerful new tool to study the physiological relevance of Gq/11-dependent signaling in distinct tissues and cell types, in the absence of β-arrestin-mediated cellular effects. Such studies should guide the development of novel classes of functionally biased ligands that show high efficacy in various pathophysiological conditions but display a reduced incidence of side effects.
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103
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Frank R, Ahrens VM, Boehnke S, Beck-Sickinger AG, Hey-Hawkins E. Back Cover: Charge-Compensated Metallacarborane Building Blocks for Conjugation with Peptides (ChemBioChem 4/2016). Chembiochem 2016. [DOI: 10.1002/cbic.201600032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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104
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Huster D, Kaiser A, Kahr J, Zellmann T, Scheidt HA, Meier R, Meiler J, Beck-Sickinger AG, Schmidt P. Structural Dynamics of the Ligand-Receptor Interaction of the Neuropeptide Y Receptor Type 2. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.1246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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105
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Frank R, Ahrens VM, Boehnke S, Beck-Sickinger AG, Hey-Hawkins E. Charge-Compensated Metallacarborane Building Blocks for Conjugation with Peptides. Chembiochem 2016; 17:308-17. [PMID: 26662708 DOI: 10.1002/cbic.201500569] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Indexed: 11/06/2022]
Abstract
The cobalt bis(dicarbollide) complex [commo-3,3'-Co(1,2-C2 B9 H11 )2 ](-) has captured much attention in biochemical and medical contexts, in particular for the treatment of tumors by boron neutron capture therapy (BNCT). Derivatives of cobalt bis(dicarbollide) are commonly prepared through ring-opening reactions of cyclic oxonium ions, so the corresponding products are usually charged. Furthermore, attempts to incorporate cobalt bis(dicarbollide) into peptides are rare, despite obvious potential advantages. Here the synthesis of an imidazolium-based charge-compensated cobalt bis(dicarbollide) building block, which allows additional modifications with moieties of biochemical relevance, such as monosaccharides, is reported. Furthermore, conjugates of these building blocks with the Y1 -receptor-selective derivative of neuropeptide Y ([F(7) ,P(34) ]-NPY) retained excellent response to hY1 receptors found to be overexpressed in breast tumors and metastases.
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106
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Lotze J, Reinhardt U, Seitz O, Beck-Sickinger AG. Peptide-tags for site-specific protein labelling in vitro and in vivo. MOLECULAR BIOSYSTEMS 2016; 12:1731-45. [DOI: 10.1039/c6mb00023a] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Peptide-tag based labelling can be achieved by (i) enzymes (ii) recognition of metal ions or small molecules and (iii) peptide–peptide interactions and enables site-specific protein visualization to investigate protein localization and trafficking.
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107
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Pagel M, Meier R, Braun K, Wiessler M, Beck-Sickinger AG. On-resin Diels–Alder reaction with inverse electron demand: an efficient ligation method for complex peptides with a varying spacer to optimize cell adhesion. Org Biomol Chem 2016; 14:4809-16. [DOI: 10.1039/c6ob00314a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The DARinvon resin is a new orthogonal reaction in peptide synthesis and the benefits for cell adhesion are discussed.
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108
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Jendrny C, Beck-Sickinger AG. Inhibition of Kallikrein-Related Peptidases 7 and 5 by Grafting Serpin Reactive-Center Loop Sequences onto Sunflower Trypsin Inhibitor-1 (SFTI-1). Chembiochem 2015; 17:719-26. [PMID: 26574674 DOI: 10.1002/cbic.201500539] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Indexed: 01/30/2023]
Abstract
Serpin proteins irreversibly inhibit serine proteases, but only a small part of the serpin reactive-center loop (RCL) is responsible for the initial protein-protein interaction (PPI). To develop peptidic protease inhibitors, kallikrein-related peptidases 7 (KLK7) and 5 (KLK5) were chosen. Firstly, we demonstrated that short peptides derived from RCL sequences can be cleaved by KLK7 in a substrate-like manner. Next, these substrates were grafted onto the protease-binding loop of sunflower trypsin inhibitor-1 (SFTI-1). Peptides based on kallistatin, α1 -antichymotrypsin, and protein C inhibitor (PCI) inhibited KLK7 with Ki =0.4, 0.5, and 0.7 μm, respectively. In contrast, the trypsin-like KLK5 was only blocked by the peptide derived from PCI (Ki =0.6 μm). Thus, serpin function can be mimicked by introducing its PPI site into the rigid structure of the SFTI-1 scaffold. This approach might be applicable not only to KLKs but also to other serine protease members, thus opening up new therapeutic fields.
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109
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Schönauer R, Kaiser A, Holze C, Babilon S, Köbberling J, Riedl B, Beck-Sickinger AG. Fluorescently labeled adrenomedullin allows real-time monitoring of adrenomedullin receptor trafficking in living cells. J Pept Sci 2015; 21:905-12. [DOI: 10.1002/psc.2833] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 10/02/2015] [Accepted: 10/05/2015] [Indexed: 01/01/2023]
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110
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Reinhardt U, Lotze J, Mörl K, Beck-Sickinger AG, Seitz O. Rapid Covalent Fluorescence Labeling of Membrane Proteins on Live Cells via Coiled-Coil Templated Acyl Transfer. Bioconjug Chem 2015; 26:2106-17. [PMID: 26367072 DOI: 10.1021/acs.bioconjchem.5b00387] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Fluorescently labeled proteins enable the microscopic imaging of protein localization and function in live cells. In labeling reactions targeted against specific tag sequences, the size of the fluorophore-tag is of major concern. The tag should be small to prevent interference with protein function. Furthermore, rapid and covalent labeling methods are desired to enable the analysis of fast biological processes. Herein, we describe the development of a method in which the formation of a parallel coiled coil triggers the transfer of a fluorescence dye from a thioester-linked coil peptide conjugate onto a cysteine-modified coil peptide. This labeling method requires only small tag sequences (max 23 aa) and occurs with high tag specificity. We show that size matching of the coil peptides and a suitable thioester reactivity allow the acyl transfer reaction to proceed within minutes (rather than hours). We demonstrate the versatility of this method by applying it to the labeling of different G-protein coupled membrane receptors including the human neuropeptide Y receptors 1, 2, 4, 5, the neuropeptide FF receptors 1 and 2, and the dopamine receptor 1. The labeled receptors are fully functional and able to bind the respective ligand with high affinity. Activity is not impaired as demonstrated by activation, internalization, and recycling experiments.
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111
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Job F, Settele F, Lorey S, Rundfeldt C, Baumann L, Beck-Sickinger AG, Haupts U, Lilie H, Bosse-Doenecke E. Ubiquitin is a versatile scaffold protein for the generation of molecules with de novo binding and advantageous drug-like properties. FEBS Open Bio 2015; 5:579-93. [PMID: 26258013 PMCID: PMC4522466 DOI: 10.1016/j.fob.2015.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/07/2015] [Accepted: 07/07/2015] [Indexed: 01/17/2023] Open
Abstract
In the search for effective therapeutic strategies, protein-based biologicals are under intense development. While monoclonal antibodies represent the majority of these drugs, other innovative approaches are exploring the use of scaffold proteins for the creation of binding molecules with tailor-made properties. Ubiquitin is especially suited for this strategy due to several key characteristics. Ubiquitin is a natural serum protein, 100% conserved across the mammalian class and possesses high thermal, structural and proteolytic stability. Because of its small size and lack of posttranslational modifications, it can be easily produced in Escherichia coli. In this work we provide evidence that ubiquitin is safe as tested experimentally in vivo. In contrast to previously published results, we show that, in our hands, ubiquitin does not act as a functional ligand of the chemokine receptor CXCR4. Cellular assays based on different signaling pathways of the receptor were conducted with the natural agonist SDF-1 as a benchmark. In none of the assays could a response to ubiquitin treatment be elicited. Furthermore, intravenous application to mice at high concentrations did not induce any detectable effect on cytokine levels or hematological parameters.
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112
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Kilian TM, Beck-Sickinger AG. Recombinant expression and characterization of biologically active protein delta homolog 1. Protein Expr Purif 2015; 110:72-8. [DOI: 10.1016/j.pep.2015.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 02/07/2015] [Accepted: 02/09/2015] [Indexed: 10/24/2022]
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113
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Kilian TM, Klöting N, Bergmann R, Els-Heindl S, Babilon S, Clément-Ziza M, Zhang Y, Beck-Sickinger AG, Chollet C. Rational design of dual peptides targeting ghrelin and Y2 receptors to regulate food intake and body weight. J Med Chem 2015; 58:4180-93. [PMID: 25905598 DOI: 10.1021/jm501702q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Ghrelin and Y2 receptors play a central role in appetite regulation inducing opposite effects. The Y2 receptor induces satiety, while the ghrelin receptor promotes hunger and weight gain. However, the food regulating system is tightly controlled by interconnected pathways where redundancies can lead to poor efficacy and drug tolerance when addressing a single molecule. We developed a multitarget strategy to synthesize dual peptides simultaneously inhibiting the ghrelin receptor and stimulating the Y2 receptor. Dual peptides showed dual activity in vitro, and one compound induced a slight diminution of food intake in a rodent model of obesity. In addition, stability studies in rats revealed different behaviors between the dual peptide and its corresponding monomers. The Y2 receptor agonist was unstable in blood, while the dual peptide showed an intermediate stability compared to that of the highly stable ghrelin receptor inverse agonist.
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114
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Kaiser A, Müller P, Zellmann T, Scheidt HA, Thomas L, Bosse M, Meier R, Meiler J, Huster D, Beck-Sickinger AG, Schmidt P. Unwinding of the C-Terminal Residues of Neuropeptide Y is critical for Y₂ Receptor Binding and Activation. Angew Chem Int Ed Engl 2015; 54:7446-9. [PMID: 25924821 DOI: 10.1002/anie.201411688] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 02/24/2015] [Indexed: 12/22/2022]
Abstract
Despite recent breakthroughs in the structural characterization of G-protein-coupled receptors (GPCRs), there is only sparse data on how GPCRs recognize larger peptide ligands. NMR spectroscopy, molecular modeling, and double-cycle mutagenesis studies were integrated to obtain a structural model of the peptide hormone neuropeptide Y (NPY) bound to its human G-protein-coupled Y2 receptor (Y2R). Solid-state NMR measurements of specific isotope-labeled NPY in complex with in vitro folded Y2R reconstituted into phospholipid bicelles provided the bioactive structure of the peptide. Guided by solution NMR experiments, it could be shown that the ligand is tethered to the second extracellular loop by hydrophobic contacts. The C-terminal α-helix of NPY, which is formed in a membrane environment in the absence of the receptor, is unwound starting at T(32) to provide optimal contacts in a deep binding pocket within the transmembrane bundle of the Y2R.
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115
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Kaiser A, Müller P, Zellmann T, Scheidt HA, Thomas L, Bosse M, Meier R, Meiler J, Huster D, Beck-Sickinger AG, Schmidt P. Die Entfaltung der C-terminalen α-Helix des Neuropeptids Y ist entscheidend für die Bindung und Aktivierung des Y2-Rezeptors. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201411688] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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116
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Böhme D, Beck-Sickinger AG. Controlling Toxicity of Peptide-Drug Conjugates by Different Chemical Linker Structures. ChemMedChem 2015; 10:804-14. [DOI: 10.1002/cmdc.201402514] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/02/2015] [Indexed: 01/17/2023]
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117
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Mörl K, Beck-Sickinger AG. Intracellular Trafficking of Neuropeptide Y Receptors. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 132:73-96. [PMID: 26055055 DOI: 10.1016/bs.pmbts.2015.02.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The multireceptor multiligand system of neuropeptide Y receptors and their ligands is involved in the regulation of a multitude of physiological and pathophysiological processes. Specific expression patterns, ligand-binding modes, and signaling properties contribute to the complex network regulating distinct cellular responses. Intracellular trafficking processes are important key steps that are regulated in context with accessory proteins. These proteins exert their influence by interacting directly or indirectly with the receptors, causing modification of the receptors, or operating as scaffolds for the assembly of larger signaling complexes. On the intracellular receptor faces, sequence-specific motifs have been identified that play an important role in this process. Interestingly, it is also possible to influence the receptor internalization by modification of the peptide ligand.
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Hofmann S, Maschauer S, Kuwert T, Beck-Sickinger AG, Prante O. Synthesis and in vitro and in vivo evaluation of an (18)F-labeled neuropeptide Y analogue for imaging of breast cancer by PET. Mol Pharm 2015; 12:1121-30. [PMID: 25748228 DOI: 10.1021/mp500601z] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Imaging of Y1R expression in breast cancer is still a challenging task. Herein, we report a suitable (18)F-labeled high-molecular-weight glycopeptide for imaging of peripheral neuropeptide Y (NPY) Y1 receptor (Y1R)-positive tumors by preclinical small-animal positron emission tomography (PET). The Y1R-preferring NPY [F(7),P(34)]NPY analogue was functionalized with an alkyne-bearing propargylglycine (Pra) in position 4. The corresponding fluoroglycosylated (FGlc) peptide analogue [Pra(4)(FGlc),F(7),P(34)]NPY and its (18)F-labeled analogue were synthesized by click chemistry-based fluoroglycosylation. The radiosynthesis was performed by (18)F-fluoroglycosylation starting from the 2-triflate of the β-mannosylazide and the alkyne peptide [Pra(4),F(7),P(34)]NPY. The radiosynthesis of the(18)F-labeled analogue was optimized using a minimum amount of peptide precursor (40 nmol), proceeding with an overall radiochemical yield of 20-25% (nondecay corrected) in a total synthesis time of 75 min with specific activities of 40-70 GBq/μmol. In comparison to NPY and [F(7),P(34)]NPY, in vitro Y1R and Y2R activation studies with the cold [Pra(4)(FGlc),F(7),P(34)]NPY on stably transfected COS-7 cells displayed a high potency for the induction of Y1R-specific inositol accumulation (pEC50 = 8.5 ± 0.1), whereas the potency at Y2R was significantly decreased. Internalization studies on stably transfected HEK293 cells confirmed a strong glycopeptide-mediated Y1R internalization and a substantial Y1R subtype selectivity over Y2R. In vitro autoradiography with Y1R-positive MCF-7 tumor tissue slices indicated high specific binding of the (18)F-labeled glycopeptide, when binding was reduced by 95% ([Pra(4),F(7),P(34)]NPY) and by 86% (BIBP3226 Y1R antagonist) in competition studies. Biodistribution and small-animal PET studies on MCF-7 breast tumor-bearing nude mice revealed radiotracer uptake in the MCF-7 tumor of 1.8%ID/g at 20 min p.i. and 0.7%ID/g at 120 min p.i. (n = 3-4), increasing tumor-to-blood ratios from 1.2 to 2.4, and a tumor retention of 76 ± 4% (n = 4; 45-90 min p.i.). PET imaging studies with MCF-7 tumor-bearing nude mice demonstrated uptake of the (18)F-labeled glycopeptide in the tumor region at 60 min p.i., whereas only negligible tumor uptake was observed in animals injected with a nonbinding (18)F-labeled glycopeptide pendant as a measure of nonspecific binding. In conclusion, PET imaging experiments with the (18)F-labeled NPY glycopeptide revealed Y1R-specific binding uptake in MCF-7 tumors in vivo together with decreased kidney uptake compared to DOTA-derivatives of this peptide. We consider this glycopeptide to be a potent lead peptide for the design of improved (18)F-glycopeptides with shorter amino acid sequences that would further facilitate PET imaging studies of Y1R-positive breast tumors.
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119
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Rojas JM, Bruinstroop E, Printz RL, Alijagic-Boers A, Foppen E, Turney MK, George L, Beck-Sickinger AG, Kalsbeek A, Niswender KD. Central nervous system neuropeptide Y regulates mediators of hepatic phospholipid remodeling and very low-density lipoprotein triglyceride secretion via sympathetic innervation. Mol Metab 2015; 4:210-21. [PMID: 25737956 PMCID: PMC4338317 DOI: 10.1016/j.molmet.2015.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 12/29/2014] [Accepted: 01/09/2015] [Indexed: 12/26/2022] Open
Abstract
OBJECTIVE Elevated very low-density lipoprotein (VLDL)-triglyceride (TG) secretion from the liver contributes to an atherogenic dyslipidemia that is associated with obesity, diabetes and the metabolic syndrome. Numerous models of obesity and diabetes are characterized by increased central nervous system (CNS) neuropeptide Y (NPY); in fact, a single intracerebroventricular (icv) administration of NPY in lean fasted rats elevates hepatic VLDL-TG secretion and does so, in large part, via signaling through the CNS NPY Y1 receptor. Thus, our overarching hypothesis is that elevated CNS NPY action contributes to dyslipidemia by activating central circuits that modulate liver lipid metabolism. METHODS Chow-fed Zucker fatty (ZF) rats were pair-fed by matching their caloric intake to that of lean controls and effects on body weight, plasma TG, and liver content of TG and phospholipid (PL) were compared to ad-libitum (ad-lib) fed ZF rats. Additionally, lean 4-h fasted rats with intact or disrupted hepatic sympathetic innervation were treated with icv NPY or NPY Y1 receptor agonist to identify novel hepatic mechanisms by which NPY promotes VLDL particle maturation and secretion. RESULTS Manipulation of plasma TG levels in obese ZF rats, through pair-feeding had no effect on liver TG content; however, hepatic PL content was substantially reduced and was tightly correlated with plasma TG levels. Treatment with icv NPY or a selective NPY Y1 receptor agonist in lean fasted rats robustly activated key hepatic regulatory proteins, stearoyl-CoA desaturase-1 (SCD-1), ADP-ribosylation factor-1 (ARF-1), and lipin-1, known to be involved in remodeling liver PL into TG for VLDL maturation and secretion. Lastly, we show that the effects of CNS NPY on key liporegulatory proteins are attenuated by hepatic sympathetic denervation. CONCLUSIONS These data support a model in which CNS NPY modulates mediators of hepatic PL remodeling and VLDL maturation to stimulate VLDL-TG secretion that is dependent on the Y1 receptor and sympathetic signaling to the liver.
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Key Words
- AGPAT, 1-acyl-glycerol-3-phosphate acyltransferase
- ARF-1, ADP-ribosylation factor-1
- ApoB, apolipoprotein B
- CNS, central nervous system
- Cyto, cytoplasmic
- DAG, diacylglycerol
- DGAT, diacylglycerol acyltransferase
- ER, endoplasmic reticulum
- FFA(s), free fatty acid(s)
- GAPDH, glyceraldehyde 3-phosphate dehydrogenase
- HDAC-1, histone deacetylase-1
- Lipin-1
- NE, norepinephrine
- NPY Y1 receptor
- NPY, neuropeptide Y
- Nuc, nuclear
- PA, phosphatidic acid
- PAP-1, phosphatidic acid phosphatase-1
- PF, pair-fed
- PL, phospholipid
- PLD, phospholipase D
- POMC, proopiomelanocortin
- Phospholipid
- RPL13A, ribosomal protein L13a
- RT-PCR, real-time PCR
- SCD-1, stearoyl-CoA desaturase-1
- SNS, sympathetic nervous system
- Sham, sham-denervation
- Sx, sympathetic denervation
- Sympathetic denervation
- TG, triglyceride
- Triglyceride
- VLDL
- VLDL, very low-density lipoprotein
- Veh, vehicle
- ZF, Zucker fatty
- ad-lib, ad-libitum
- icv, intracerebroventricular
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Böhme D, Beck-Sickinger AG. Drug delivery and release systems for targeted tumor therapy. J Pept Sci 2015; 21:186-200. [PMID: 25703117 DOI: 10.1002/psc.2753] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 12/19/2014] [Accepted: 12/19/2014] [Indexed: 12/11/2022]
Abstract
Most toxic agents currently used for chemotherapy show a narrow therapeutic window, because of their inability to distinguish between healthy and cancer cells. Targeted drug delivery offers the possibility to overcome this issue by selectively addressing structures on the surface of cancer cells, therefore reducing undesired side effects. In this broad field, peptide-drug conjugates linked by intracellular cleavable structures have evolved as highly promising agents. They can specifically deliver toxophores to tumor cells by targeting distinct receptors overexpressed in cancer. In this review, we focus on these compounds and describe important factors to develop a highly efficient peptide-drug conjugate. The necessary properties of tumor-targeting peptides are described, and the different options for cleavable linkers used to connect toxic agents and peptides are discussed, and synthetic considerations for the introduction of these structures are reported. Furthermore, recent examples and current developments of peptide-drug conjugates are critically evaluated with a special focus on the applied linker structures and their future use in cancer therapy.
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121
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Frank R, Ahrens V, Boehnke S, Hofmann S, Kellert M, Saretz S, Pandey S, Sárosi M, Bartók Á, Beck-Sickinger AG, Hey-Hawkins E. Carbaboranes – more than just phenyl mimetics. PURE APPL CHEM 2015. [DOI: 10.1515/pac-2014-1006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractDicarba-closo-dodecaboranes(12) (C2B10H12, carbaboranes) are highly hydrophobic and stable icosahedral carbon-containing boron clusters. The cage framework of these clusters can be modified with a variety of substituents, both at the carbon and at the boron atoms. Substituted carbaboranes are of interest in medicine as boron neutron capture therapy (BNCT) agents or as pharmacophores. High and selective accumulation in tumour cells is an important requirement for a BNCT agent and is achieved by incorporating boron-rich, water-soluble carbaborane derivatives into breast tumour-selective modified neuropeptide Y, [F7, P34]-NPY. Preliminary studies showed that the receptor binding affinity and signal transduction of the boron-modified peptides were very well retained. Use of carbaboranes as pharmacophores was shown by replacement of Bpa32 (Bpa=benzoylphenylalanine) in the reduced-size NPY analogue [Pro30, Nle31, Bpa32, Leu34]-NPY 28–36 by ortho-carbaboranyl propanoic acid. The inclusion of the carbaborane derivative resulted in a short NPY agonist with an interesting hY2R/hY4R preference. This might be a promising approach in the field of anti-obesity drug development.
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Mäde V, Bellmann-Sickert K, Kaiser A, Meiler J, Beck-Sickinger AG. Back Cover: Position and Length of Fatty Acids Strongly Affect Receptor Selectivity Pattern of Human Pancreatic Polypeptide Analogues (ChemMedChem 11/2014). ChemMedChem 2014. [DOI: 10.1002/cmdc.201490043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Ahrens VM, Frank R, Boehnke S, Schütz CL, Hampel G, Iffland DS, Bings NH, Hey-Hawkins E, Beck-Sickinger AG. Receptor-Mediated Uptake of Boron-Rich Neuropeptide Y Analogues for Boron Neutron Capture Therapy. ChemMedChem 2014; 10:164-72. [DOI: 10.1002/cmdc.201402368] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Indexed: 12/31/2022]
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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]
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Mäde V, Bellmann-Sickert K, Kaiser A, Meiler J, Beck-Sickinger AG. Position and length of fatty acids strongly affect receptor selectivity pattern of human pancreatic polypeptide analogues. ChemMedChem 2014; 9:2463-74. [PMID: 25156249 DOI: 10.1002/cmdc.201402235] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Indexed: 12/25/2022]
Abstract
Pancreatic polypeptide (PP) is a satiety-inducing gut hormone targeting predominantly the Y4 receptor within the neuropeptide Y multiligand/multireceptor family. Palmitoylated PP-based ligands have already been reported to exert prolonged satiety-inducing effects in animal models. Here, we suggest that other lipidation sites and different fatty acid chain lengths may affect receptor selectivity and metabolic stability. Activity tests revealed significantly enhanced potency of long fatty acid conjugates on all four Y receptors with a preference of position 22 over 30 at Y1 , Y2 and Y5 receptors. Improved Y receptor selectivity was observed for two short fatty acid analogues. Moreover, [K(30)(E-Prop)]hPP2-36 (15) displayed enhanced stability in blood plasma and liver homogenates. Thus, short chain lipidation of hPP at key residue 30 is a promising approach for anti-obesity therapy because of maintained selectivity and a sixfold increased plasma half-life.
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