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Zernia S, Frank R, Weiße RHJ, Jahnke HG, Bellmann-Sickert K, Prager A, Abel B, Sträter N, Robitzki A, Beck-Sickinger AG. Surface-Binding Peptide Facilitates Electricity-Driven NADPH-Free Cytochrome P450 Catalysis. ChemCatChem 2018. [DOI: 10.1002/cctc.201701810] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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77
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Zitzmann FD, Jahnke HG, Nitschke F, Beck-Sickinger AG, Abel B, Belder D, Robitzki AA. A novel microfluidic microelectrode chip for a significantly enhanced monitoring of NPY-receptor activation in live mode. LAB ON A CHIP 2017; 17:4294-4302. [PMID: 29119176 DOI: 10.1039/c7lc00754j] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Lab-on-a-chip devices that combine, e.g. chemical synthesis with integrated on-chip analytics and multi-compartment organ-on-a-chip approaches, are a fast and attractive evolving research area. While integration of appropriate cell models in microfluidic setups for monitoring the biological activity of synthesis products or test compounds is already in focus, the integration of label-free bioelectronic analysis techniques is still poorly realized. In this context, we investigated the capabilities of impedance spectroscopy as a non-destructive real-time monitoring technique for adherent cell models in a microfluidic setup. While an initial adaptation of a microelectrode array (MEA) layout from a static setup revealed clear restrictions in the application of impedance spectroscopy in a microfluidic chip, we could demonstrate the advantage of a FEM simulation based rational MEA layout optimization for an optimum electrical field distribution within microfluidic structures. Furthermore, FEM simulation based analysis of shear stress and time-dependent test compound distribution led to identification of an optimal flow rate. Based on the simulation derived optimized microfluidic MEA, comparable impedance spectra characteristics were achieved for HEK293A cells cultured under microfluidic and static conditions. Furthermore, HEK293A cells expressing Y1 receptors were used to successfully demonstrate the capabilities of impedimetric monitoring of cellular alterations in the microfluidic setup. More strikingly, the maximum impedimetric signal for the receptor activation was significantly increased by a factor of 2.8. Detailed investigations of cell morphology and motility led to the conclusion that cultivation under microfluidic conditions could lead to an extended and stabilized cell-electrode interface.
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Schubert M, Stichel J, Du Y, Tough IR, Sliwoski G, Meiler J, Cox HM, Weaver CD, Beck-Sickinger AG. Identification and Characterization of the First Selective Y4 Receptor Positive Allosteric Modulator. J Med Chem 2017; 60:7605-7612. [DOI: 10.1021/acs.jmedchem.7b00976] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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79
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Jouy F, Lohmann N, Wandel E, Ruiz-Gómez G, Pisabarro MT, Beck-Sickinger AG, Schnabelrauch M, Möller S, Simon JC, Kalkhof S, von Bergen M, Franz S. Sulfated hyaluronan attenuates inflammatory signaling pathways in macrophages involving induction of antioxidants. Proteomics 2017; 17:e1700082. [PMID: 28337837 DOI: 10.1002/pmic.201700082] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 03/22/2017] [Indexed: 01/08/2023]
Abstract
It is well recognized that high molecular weight hyaluronan (H-HA) exerts potent anti-inflammatory effects while its fragmentation into low molecular weight HA (L-HA) is discussed to promote inflammation. Chemical modification of HA with sulfate groups has been shown to foster its anti-inflammatory activity which seems to be maintained in sulfated low molecular weight HA derivatives (sL-HA). However, the molecular mechanisms by which sL-HA produces its anti-inflammatory activity are not understood. In this study, we used global quantitative proteomics combined with targeted analysis of key proteins to characterize the effect of sL-HA on fully differentiated human inflammatory macrophages (iMФ). Culture of iMФ with sL-HA did not affect cell viability but resulted in a reduced pro-inflammatory cytokine response of iMФ after activation indicating a profound counter-regulation of their initial inflammatory phenotype. Rapid internalization of sL-HA involving CD44 and scavenger receptors was observed. Furthermore, an upregulation of the antioxidants SOD2 and SOD3 was found while no oxidative stress was induced. Consequently, activity of transcription factors for inflammatory gene expression was downregulated in iMФ with sL-HA after activation whereas anti-inflammatory proteins were induced. This study proves anti-inflammatory properties of sL-HA and provides information on its regulatory mode of action on iMФ.
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80
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Moldovan RP, Els-Heindl S, Worm DJ, Kniess T, Kluge M, Beck-Sickinger AG, Deuther-Conrad W, Krügel U, Brust P. Development of Fluorinated Non-Peptidic Ghrelin Receptor Ligands for Potential Use in Molecular Imaging. Int J Mol Sci 2017; 18:ijms18040768. [PMID: 28379199 PMCID: PMC5412352 DOI: 10.3390/ijms18040768] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/23/2017] [Accepted: 03/31/2017] [Indexed: 12/19/2022] Open
Abstract
The ghrelin receptor (GhrR) is a widely investigated target in several diseases. However, the current knowledge of its role and distribution in the brain is limited. Recently, the small and non-peptidic compound (S)-6-(4-bromo-2-fluorophenoxy)-3-((1-isopropylpiperidin-3-yl)methyl)-2-methylpyrido[3,2-d]pyrimidin-4(3H)-one ((S)-9) has been described as a GhrR ligand with high binding affinity. Here, we describe the synthesis of fluorinated derivatives, the in vitro evaluation of their potency as partial agonists and selectivity at GhrRs, and their physicochemical properties. These results identified compounds (S)-9, (R)-9, and (S)-16 as suitable parent molecules for 18F-labeled positron emission tomography (PET) radiotracers to enable future investigation of GhrR in the brain.
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81
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Schönauer R, Els-Heindl S, Beck-Sickinger AG. Adrenomedullin - new perspectives of a potent peptide hormone. J Pept Sci 2017; 23:472-485. [DOI: 10.1002/psc.2953] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 11/24/2016] [Accepted: 11/28/2016] [Indexed: 12/14/2022]
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82
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Els-Heindl S, Bellmann-Sickert K, Beck-Sickinger AG. C-terminus of a hexapeptidic ghrelin receptor inverse agonist can switch peptide behavior from inverse agonism to agonism. Biopolymers 2017; 106:101-8. [PMID: 26566778 DOI: 10.1002/bip.22768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/05/2015] [Accepted: 11/09/2015] [Indexed: 11/10/2022]
Abstract
Subtle changes in the sequence at the N-terminus and in the aromatic core of hexapeptidic ghrelin receptor inverse agonists can switch behavior from inverse agonism to agonism, but the C-terminal role of the sequence is unclear. Thus, analogs of the ghrelin receptor inverse agonist KbFwLL-NH2 (b = β-(3-benzothienyl)-d-alanine) were synthesized by solid phase peptide synthesis in order to identify the influence of aromaticity, charge, and hydrophobicity. Potency and efficacy of the hexapeptides were evaluated in inositol triphosphate turnover assays. Notably, modifications directly at the C-terminal Leu(6) could influence peptide efficacy leading to decreased constitutive activity. High hydrophobicity at the C-terminal position was of importance for elevated inverse agonist activity, the introduction of charged amino acids led to decreased potency. In contrast, structure-activity relationship studies of Leu(5) located closer to the aromatic core revealed an agonism-inducing position. These findings imply that amino acids with possible cation-π or π-π interactions and a suitable orientation at the C-terminus of the aromatic core induce agonism. Receptor binding studies showed that most peptides bind to the receptor at a concentration of 1 µM and modification directly at the C-terminus is generally more accepted than Leu(5) substitution. Interestingly, this observation is not dependent on the type of modification. These studies reveal another switch region of the short ghrelin receptor ligand pointing out the sensitivity of the ghrelin receptor binding pocket.
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83
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Pagel M, Beck-Sickinger AG. Multifunctional biomaterial coatings: synthetic challenges and biological activity. Biol Chem 2017; 398:3-22. [DOI: 10.1515/hsz-2016-0204] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 07/29/2016] [Indexed: 12/19/2022]
Abstract
Abstract
A controlled interaction of materials with their surrounding biological environment is of great interest in many fields. Multifunctional coatings aim to provide simultaneous modulation of several biological signals. They can consist of various combinations of bioactive, and bioinert components as well as of reporter molecules to improve cell-material contacts, prevent infections or to analyze biochemical events on the surface. However, specific immobilization and particular assembly of various active molecules are challenging. Herein, an overview of multifunctional coatings for biomaterials is given, focusing on synthetic strategies and the biological benefits by displaying several motifs.
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84
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Burkert K, Zellmann T, Meier R, Kaiser A, Stichel J, Meiler J, Mittapalli GK, Roberts E, Beck-Sickinger AG. A Deep Hydrophobic Binding Cavity is the Main Interaction for Different Y 2 R Antagonists. ChemMedChem 2016; 12:75-85. [PMID: 27874262 DOI: 10.1002/cmdc.201600433] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/28/2016] [Indexed: 12/29/2022]
Abstract
The neuropeptide Y2 receptor (Y2 R) is involved in various pathophysiological processes such as epilepsy, mood disorders, angiogenesis, and tumor growth. Therefore, the Y2 R is an interesting target for drug development. A detailed understanding of the binding pocket could facilitate the development of highly selective antagonists to study the role of Y2 R in vitro and in vivo. In this study, several residues crucial to the interaction of BIIE0246 and SF-11 derivatives with Y2 R were investigated by signal transduction assays. Using the experimental results as constraints, the antagonists were docked into a comparative structural model of the Y2 R. Despite differences in size and structure, all three antagonists display a similar binding site, including a deep hydrophobic cavity formed by transmembrane helices (TM) 4, 5, and 6, as well as a hydrophobic patch at the top of TM2 and 7. Additionally, we suggest that the antagonists block Q3.32 , a position that has been shown to be crucial for binding of the amidated C terminus of NPY and thus for receptor activation.
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85
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Ansorge M, Rastig N, Steinborn R, König T, Baumann L, Möller S, Schnabelrauch M, Cross M, Werner C, Beck-Sickinger AG, Pompe T. Corrigendum to "Short-range cytokine gradients to mimic paracrine cell interactions in vitro" [J. Control. Release 224 (2016) 59-68]. J Control Release 2016; 241:243. [PMID: 27688089 DOI: 10.1016/j.jconrel.2016.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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86
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Juhl C, Els-Heindl S, Schönauer R, Redlich G, Haaf E, Wunder F, Riedl B, Burkhardt N, Beck-Sickinger AG, Bierer D. Cover Picture: Development of Potent and Metabolically Stable APJ Ligands with High Therapeutic Potential (ChemMedChem 21/2016). ChemMedChem 2016. [DOI: 10.1002/cmdc.201600531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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87
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Thieme V, Jolly N, Madsen AN, Bellmann-Sickert K, Schwartz TW, Holst B, Cox HM, Beck-Sickinger AG. High molecular weight PEGylation of human pancreatic polypeptide at position 22 improves stability and reduces food intake in mice. Br J Pharmacol 2016; 173:3208-3221. [PMID: 27545829 DOI: 10.1111/bph.13582] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Human pancreatic polypeptide (hPP) is known to suppress appetite and food intake, thereby representing a potential therapeutic approach against obesity and associated metabolic disorders. The aim of this study was to improve hPP stability by covalent PEGylation with diverse molecular weight polyethylene glycols (PEGs) at two positions using promising lead structures while maintaining target activity. EXPERIMENTAL APPROACH Modified peptides were synthesized by combined solid-phase and solution-phase peptide synthesis. Their potency was investigated in constitutively expressing human epithelial cells and isolated human colonic mucosa as well as receptor-transfected artificial cell lines. Human blood plasma and porcine liver homogenates were used to examine the in vitro stability of the analogues. The most promising variants were injected s.c. in C57BL/6JRj mice to monitor fasting-induced food intake and bioavailability. KEY RESULTS In human epithelia and colonic mucosal preparations, activity of the modified hPP peptides depended on the core sequence and latency of the peptides was related to PEG size. Peptides modified with a 22 kDa PEG (PEG22) remained intact in blood plasma and on incubation with liver homogenates for more than 96 h. Finally, hPP2-36 , [K22 (PEG22)]hPP2-36 and [K22 (PEG22),Q34 ]hPP significantly reduced cumulative food intake in mice over 16 h after s.c. administration. CONCLUSIONS AND IMPLICATIONS Modification with PEG22 at position 22 stabilizes hPP significantly while extending its biological activities and could be used in drug development prospectively.
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88
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Ratner C, Skov LJ, Raida Z, Bächler T, Bellmann-Sickert K, Le Foll C, Sivertsen B, Dalbøge LS, Hartmann B, Beck-Sickinger AG, Madsen AN, Jelsing J, Holst JJ, Lutz TA, Andrews ZB, Holst B. Effects of Peripheral Neurotensin on Appetite Regulation and Its Role in Gastric Bypass Surgery. Endocrinology 2016; 157:3482-92. [PMID: 27580810 DOI: 10.1210/en.2016-1329] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Neurotensin (NT) is a peptide expressed in the brain and in the gastrointestinal tract. Brain NT inhibits food intake, but the effects of peripheral NT are less investigated. In this study, peripheral NT decreased food intake in both mice and rats, which was abolished by a NT antagonist. Using c-Fos immunohistochemistry, we found that peripheral NT activated brainstem and hypothalamic regions. The anorexigenic effect of NT was preserved in vagotomized mice but lasted shorter than in sham-operated mice. This in combination with a strong increase in c-Fos activation in area postrema after ip administration indicates that NT acts both through the blood circulation and the vagus. To improve the pharmacokinetics of NT, we developed a pegylated NT peptide, which presumably prolonged the half-life, and thus, the effect on feeding was extended compared with native NT. On a molecular level, the pegylated NT peptide increased proopiomelanocortin mRNA in the arcuate nucleus. We also investigated the importance of NT for the decreased food intake after gastric bypass surgery in a rat model of Roux-en-Y gastric bypass (RYGB). NT was increased in plasma and in the gastrointestinal tract in RYGB rats, and pharmacological antagonism of NT increased food intake transiently in RYGB rats. Taken together, our data suggest that NT is a metabolically active hormone, which contributes to the regulation of food intake.
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89
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Juhl C, Els-Heindl S, Schönauer R, Redlich G, Haaf E, Wunder F, Riedl B, Burkhardt N, Beck-Sickinger AG, Bierer D. Development of Potent and Metabolically Stable APJ Ligands with High Therapeutic Potential. ChemMedChem 2016; 11:2378-2384. [DOI: 10.1002/cmdc.201600307] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Indexed: 12/18/2022]
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90
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Gladytz A, John T, Gladytz T, Hassert R, Pagel M, Risselada HJ, Naumov S, Beck-Sickinger AG, Abel B. Peptides@mica: from affinity to adhesion mechanism. Phys Chem Chem Phys 2016; 18:23516-27. [PMID: 27491508 DOI: 10.1039/c6cp03325c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Investigating the adsorption of peptides on inorganic surfaces, on the molecular level, is fundamental for medicinal and analytical applications. Peptides can be potent as linkers between surfaces and living cells in biochips or in implantation medicine. Here, we studied the adsorption process of the positively charged pentapeptide RTHRK, a recently identified binding sequence for surface oxidized silicon, and novel analogues thereof to negatively charged mica surfaces. Homogeneous formation of monolayers in the nano- and low micromolar peptide concentration range was observed. We propose an alternative and efficient method to both quantify binding affinity and follow adhesion behavior. This method makes use of the thermodynamic relationship between surface coverage, measured by atomic force microscopy (AFM), and the concomitant free energy of adhesion. A knowledge-based fit to the autocorrelation of the AFM images was used to correct for a biased surface coverage introduced by the finite lateral resolution of the AFM. Binding affinities and mechanisms were further explored by large scale molecular dynamics (MD) simulations. The combination of well validated MD simulations with topological data from AFM revealed a better understanding of peptide adsorption processes on the atomistic scale. We demonstrate that binding affinity is strongly determined by a peptide's ability to form salt bridges and hydrogen bonds with the surface lattice. Consequently, differences in hydrogen bond formation lead to substantial differences in binding affinity despite conservation of the peptide's overall charge. Further, MD simulations give access to relative changes in binding energy of peptide variations in comparison to a lead compound.
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91
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Panitz N, Theisgen S, Samsonov SA, Gehrcke JP, Baumann L, Bellmann-Sickert K, Köhling S, Pisabarro MT, Rademann J, Huster D, Beck-Sickinger AG. The structural investigation of glycosaminoglycan binding to CXCL12 displays distinct interaction sites. Glycobiology 2016; 26:1209-1221. [DOI: 10.1093/glycob/cww059] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 05/15/2016] [Accepted: 05/15/2016] [Indexed: 12/14/2022] Open
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92
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Sliwoski G, Schubert M, Stichel J, Weaver D, Beck-Sickinger AG, Meiler J. Discovery of Small-Molecule Modulators of the Human Y4 Receptor. PLoS One 2016; 11:e0157146. [PMID: 27294784 PMCID: PMC4905667 DOI: 10.1371/journal.pone.0157146] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Accepted: 05/25/2016] [Indexed: 12/11/2022] Open
Abstract
The human neuropeptide Y4 receptor (Y4R) and its native ligand, pancreatic polypeptide, are critically involved in the regulation of human metabolism by signaling satiety and regulating food intake, as well as increasing energy expenditure. Thus, this receptor represents a putative target for treatment of obesity. With respect to new approaches to treat complex metabolic disorders, especially in multi-receptor systems, small molecule allosteric modulators have been in the focus of research in the last years. However, no positive allosteric modulators or agonists of the Y4R have been described so far. In this study, small molecule compounds derived from the Niclosamide scaffold were identified by high-throughput screening to increase Y4R activity. Compounds were characterized for their potency and their effects at the human Y4R and as well as their selectivity towards Y1R, Y2R and Y5R. These compounds provide a structure-activity relationship profile around this common scaffold and lay the groundwork for hit-to-lead optimization and characterization of positive allosteric modulators of the Y4R.
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93
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Schönauer R, Els-Heindl S, Fischer JP, Köbberling J, Riedl B, Beck-Sickinger AG. Adrenomedullin 2.0: Adjusting Key Levers for Metabolic Stability. J Med Chem 2016; 59:5695-705. [PMID: 27166982 DOI: 10.1021/acs.jmedchem.6b00126] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The 52 amino acid peptide hormone adrenomedullin (ADM) plays a major role in the development and regulation of the cardiovascular and lymphatic system and has therefore gained significant interest for clinical applications. Because adrenomedullin exhibits low metabolic stability, enhancement of the plasma half-life is essential for peptide-based drug design. Fluorescently labeled ADM analogues synthesized by Fmoc/t-Bu solid phase peptide synthesis were used to analyze their enzymatic degradation and specific fragmentation pattern in human blood plasma. The determination of important cleavage sites allowed the development of selectively modified peptides in a rational approach. By combination of palmitoylation, lactam-bridging, and Nα-methylation, ADM analogues protected from enzymatic cleavage in human blood were developed and revealed an explicitly elongated half-life of 5 days in comparison to the wild-type in vitro. This triple-modification did not alter the selectivity of the analogues at the AM1 receptor, highlighting their potential for therapeutic applications.
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94
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Verma D, Hörmer B, Bellmann-Sickert K, Thieme V, Beck-Sickinger AG, Herzog H, Sperk G, Tasan RO. Pancreatic polypeptide and its central Y4 receptors are essential for cued fear extinction and permanent suppression of fear. Br J Pharmacol 2016; 173:1925-38. [PMID: 26844810 PMCID: PMC4882497 DOI: 10.1111/bph.13456] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 01/26/2016] [Accepted: 01/29/2016] [Indexed: 12/18/2022] Open
Abstract
Background and purpose Avoiding danger and finding food are closely related behaviours that are essential for surviving in a natural environment. Growing evidence supports an important role of gut‐brain peptides in modulating energy homeostasis and emotional‐affective behaviour. For instance, postprandial release of pancreatic polypeptide (PP) reduced food intake and altered stress‐induced motor activity and anxiety by activating central Y4 receptors. Experimental approach We characterized [K30(PEG2)]hPP2‐36 as long‐acting Y4 receptor agonist and injected it peripherally into wildtype and Y4 receptor knockout (Y4KO) C57Bl/6NCrl mice to investigate the role of Y4 receptors in fear conditioning. Extinction and relapse after extinction was measured by spontaneous recovery and renewal. Key results The Y4KO mice showed impaired cued and context fear extinction without affecting acquisition, consolidation or recall of fear. Correspondingly, peripheral injection of [K30(PEG2)]hPP2‐36 facilitated extinction learning upon fasting, an effect that was long‐lasting and generalized. Furthermore, peripherally applied [K30(PEG2)]hPP2‐36 before extinction inhibited the activation of orexin‐expressing neurons in the lateral hypothalamus in WT, but not in Y4KO mice. Conclusions and implications Our findings suggests suppression of excessive arousal as a possible mechanism for the extinction‐promoting effect of central Y4 receptors and provide strong evidence that fear extinction requires integration of vegetative stimuli with cortical and subcortical information, a process crucially depending on Y4 receptors. Importantly, in the lateral hypothalamus two peptide systems, PP and orexin, interact to generate an emotional response adapted to the current homeostatic state. Detailed investigations of feeding‐relevant genes may thus deliver multiple intervention points for treating anxiety‐related disorders.
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95
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Jendrny C, Beck-Sickinger AG. Inside Back Cover: Inhibition of Kallikrein-Related Peptidases 7 and 5 by Grafting Serpin Reactive-Center Loop Sequences onto Sunflower Trypsin Inhibitor-1 (SFTI-1) (ChemBioChem 8/2016). Chembiochem 2016. [DOI: 10.1002/cbic.201600146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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96
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Böhme D, Krieghoff J, Beck-Sickinger AG. Double Methotrexate-Modified Neuropeptide Y Analogues Express Increased Toxicity and Overcome Drug Resistance in Breast Cancer Cells. J Med Chem 2016; 59:3409-17. [DOI: 10.1021/acs.jmedchem.6b00043] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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97
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Deluca SH, Rathmann D, Beck-Sickinger AG, Meiler J. The activity of prolactin releasing peptide correlates with its helicity. Biopolymers 2016; 99:314-25. [PMID: 23426574 DOI: 10.1002/bip.22162] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/30/2012] [Accepted: 09/15/2012] [Indexed: 11/09/2022]
Abstract
The prolactin releasing peptide (PrRP) is involved in regulating food intake and body weight homeostasis, but molecular details on the activation of the PrRP receptor remain unclear. C-terminal segments of PrRP with 20 (PrRP20) and 13 (PrRP8-20) amino acids, respectively, have been suggested to be fully active. The data presented herein indicate this is true for the wildtype receptor only; a 5-10-fold loss of activity was found for PrRP8-20 compared to PrRP20 at two extracellular loop mutants of the receptor. To gain insight into the secondary structure of PrRP, we used CD spectroscopy performed in TFE and SDS. Additionally, previously reported NMR data, combined with ROSETTANMR, were employed to determine the structure of amidated PrRP20. The structural ensemble agrees with the spectroscopic data for the full-length peptide, which exists in an equilibrium between α- and 3(10)-helix. We demonstrate that PrRP8-20's reduced propensity to form an α-helix correlates with its reduced biological activity on mutant receptors. Further, distinct amino acid replacements in PrRP significantly decrease affinity and activity but have no influence on the secondary structure of the peptide. We conclude that formation of a primarily α-helical C-terminal region of PrRP is critical for receptor activation.
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98
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Zernia S, Ott F, Bellmann-Sickert K, Frank R, Klenner M, Jahnke HG, Prager A, Abel B, Robitzki A, Beck-Sickinger AG. Peptide-Mediated Specific Immobilization of Catalytically Active Cytochrome P450 BM3 Variant. Bioconjug Chem 2016; 27:1090-7. [DOI: 10.1021/acs.bioconjchem.6b00074] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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99
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Pagel M, Hassert R, John T, Braun K, Wießler M, Abel B, Beck-Sickinger AG. Multifunctional Coating Improves Cell Adhesion on Titanium by using Cooperatively Acting Peptides. Angew Chem Int Ed Engl 2016; 55:4826-30. [PMID: 26938787 DOI: 10.1002/anie.201511781] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Indexed: 11/08/2022]
Abstract
Promotion of cell adhesion on biomaterials is crucial for the long-term success of a titanium implant. Herein a novel concept is highlighted combining very stable and affine titanium surface adhesive properties with specific cell binding moieties in one molecule. A peptide containing L-3,4-dihydroxyphenylalanine was synthesized and affinity to titanium was investigated. Modification with a cyclic RGD peptide and a heparin binding peptide (HBP) was realized by an efficient on-resin combination of Diels-Alder reaction with inverse electron demand and Cu(I) catalyzed azide-alkyne cycloaddition. The peptide was fluorescently labeled by thiol Michael addition. Conjugating the cyclic RGD and HBP in one peptide gave improved spreading, proliferation, viability, and the formation of well-developed actin cytoskeleton and focal contacts of osteoblast-like cells.
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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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