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Phạm TTT, Murza A, Marsault É, Frampton JP, Rainey JK. Localized apelin-17 analogue-bicelle interactions as a facilitator of membrane-catalyzed receptor recognition and binding. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184289. [PMID: 38278504 DOI: 10.1016/j.bbamem.2024.184289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024]
Abstract
The apelinergic system encompasses two peptide ligand families, apelin and apela, along with the apelin receptor (AR or APJ), a class A G-protein-coupled receptor. This system has diverse physiological effects, including modulating heart contraction, vasodilation/constriction, glucose regulation, and vascular development, with involvement in a variety of pathological conditions. Apelin peptides have been previously shown to interact with and become structured upon binding to anionic micelles, consistent with a membrane-catalyzed mechanism of ligand-receptor binding. To overcome the challenges of observing nuclear magnetic resonance (NMR) spectroscopy signals of a dilute peptide in biological environments, 19F NMR spectroscopy, including diffusion ordered spectroscopy (DOSY) and saturation transfer difference (STD) experiments, was used herein to explore the membrane-interactive behaviour of apelin. NMR-optimized apelin-17 analogues with 4-trifluoromethyl-phenylalanine at various positions were designed and tested for bioactivity through ERK activation in stably-AR transfected HEK 293 T cells. Far-UV circular dichroism (CD) spectropolarimetry and 19F NMR spectroscopy were used to compare the membrane interactions of these analogues with unlabelled apelin-17 in both zwitterionic/neutral and net-negative bicelle conditions. Each analogue binds to bicelles with relatively weak affinity (i.e., in fast exchange on the NMR timescale), with preferential interactions observed at the cationic residue-rich N-terminal and mid-length regions of the peptide leaving the C-terminal end unencumbered for receptor recognition, enabling a membrane-anchored fly-casting mechanism of peptide search for the receptor. In all, this study provides further insight into the membrane-interactive behaviour of an important bioactive peptide, demonstrating interactions and biophysical behaviour that cannot be neglected in therapeutic design.
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Affiliation(s)
- Trần Thanh Tâm Phạm
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Alexandre Murza
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Éric Marsault
- Department of Pharmacology and Physiology, Faculty of Medicine and Health Sciences, Institut de Pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - John P Frampton
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada; School of Biomedical Engineering, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Jan K Rainey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada; School of Biomedical Engineering, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Chemistry, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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2
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Pisarenko OI, Studneva IM. Modified APJ Receptor Peptide Ligands as Postconditioning Drugs in Myocardial Ischaemia/Reperfusion Injury. Int J Pept Res Ther 2023. [DOI: 10.1007/s10989-023-10498-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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3
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Damjanovic J, Miao J, Huang H, Lin YS. Elucidating Solution Structures of Cyclic Peptides Using Molecular Dynamics Simulations. Chem Rev 2021; 121:2292-2324. [PMID: 33426882 DOI: 10.1021/acs.chemrev.0c01087] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Protein-protein interactions are vital to biological processes, but the shape and size of their interfaces make them hard to target using small molecules. Cyclic peptides have shown promise as protein-protein interaction modulators, as they can bind protein surfaces with high affinity and specificity. Dozens of cyclic peptides are already FDA approved, and many more are in various stages of development as immunosuppressants, antibiotics, antivirals, or anticancer drugs. However, most cyclic peptide drugs so far have been natural products or derivatives thereof, with de novo design having proven challenging. A key obstacle is structural characterization: cyclic peptides frequently adopt multiple conformations in solution, which are difficult to resolve using techniques like NMR spectroscopy. The lack of solution structural information prevents a thorough understanding of cyclic peptides' sequence-structure-function relationship. Here we review recent development and application of molecular dynamics simulations with enhanced sampling to studying the solution structures of cyclic peptides. We describe novel computational methods capable of sampling cyclic peptides' conformational space and provide examples of computational studies that relate peptides' sequence and structure to biological activity. We demonstrate that molecular dynamics simulations have grown from an explanatory technique to a full-fledged tool for systematic studies at the forefront of cyclic peptide therapeutic design.
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Affiliation(s)
- Jovan Damjanovic
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Jiayuan Miao
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - He Huang
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Yu-Shan Lin
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
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4
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Marsault E, Llorens-Cortes C, Iturrioz X, Chun HJ, Lesur O, Oudit GY, Auger-Messier M. The apelinergic system: a perspective on challenges and opportunities in cardiovascular and metabolic disorders. Ann N Y Acad Sci 2019; 1455:12-33. [PMID: 31236974 PMCID: PMC6834863 DOI: 10.1111/nyas.14123] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/11/2019] [Accepted: 05/02/2019] [Indexed: 12/11/2022]
Abstract
The apelinergic pathway has been generating increasing interest in the past few years for its potential as a therapeutic target in several conditions associated with the cardiovascular and metabolic systems. Indeed, preclinical and, more recently, clinical evidence both point to this G protein-coupled receptor as a target of interest in the treatment of not only cardiovascular disorders such as heart failure, pulmonary arterial hypertension, atherosclerosis, or septic shock, but also of additional conditions such as water retention/hyponatremic disorders, type 2 diabetes, and preeclampsia. While it is a peculiar system with its two classes of endogenous ligand, the apelins and Elabela, its intricacies are a matter of continuing investigation to finely pinpoint its potential and how it enables crosstalk between the vasculature and organ systems of interest. In this perspective article, we first review the current knowledge on the role of the apelinergic pathway in the above systems, as well as the associated therapeutic indications and existing pharmacological tools. We also offer a perspective on the challenges and potential ahead to advance the apelinergic system as a target for therapeutic intervention in several key areas.
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Affiliation(s)
- Eric Marsault
- Department of Pharmacology and Physiology, Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Catherine Llorens-Cortes
- Collège de France, Center for Interdisciplinary Research in Biology, INSERM U1050, CNRS UMR7241, Paris, France
| | - Xavier Iturrioz
- Collège de France, Center for Interdisciplinary Research in Biology, INSERM U1050, CNRS UMR7241, Paris, France
| | - Hyung J. Chun
- Yale Cardiovascular Research Center, Section of Cardiovascular Medicine, Departments of Internal Medicine and Pathology, Yale University School of Medicine, New Haven, Connecticut
| | - Olivier Lesur
- Department of Pharmacology and Physiology, Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
- Department of Medicine – Division of Intensive Care Units, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Gavin Y. Oudit
- Department of Medicine, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Canada
| | - Mannix Auger-Messier
- Department of Pharmacology and Physiology, Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
- Department of Medicine – Division of Cardiology, Centre de Recherche du CHUS, Université de Sherbrooke, Sherbrooke, Québec, Canada
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5
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Simmons JR, Murza A, Lumsden MD, Kenward C, Marsault É, Rainey JK. Simultaneous Ligand and Receptor Tracking through NMR Spectroscopy Enabled by Distinct 19F Labels. Int J Mol Sci 2019; 20:ijms20153658. [PMID: 31357423 PMCID: PMC6696318 DOI: 10.3390/ijms20153658] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 01/07/2023] Open
Abstract
To probe ligand-receptor binding at the atomic-level, a frequent approach involves multidimensional nuclear magnetic resonance (NMR) spectroscopy experiments relying on 13C- and/or 15N-enrichment alongside 1H. Alternatively, the lack of fluorine in biomolecules may be exploited through specific incorporation of 19F nuclei into a sample. The 19F nucleus is highly sensitive to environmental changes and allows for one-dimensional NMR spectroscopic study, with perturbation to chemical shift and spin dynamics diagnostic of structural change, ligand binding, and modified conformational sampling. This was applied to the apelinergic system, which comprises a rhodopsin-like G protein-coupled receptor (the apelin receptor (AR)/APJ) and two families of cognate ligands, the apelin and apela (ELABELA/toddler) peptides. Specifically, AR fragments consisting of either the N-terminal tail and first transmembrane (TM) α-helix (AR55) or the first three transmembrane α-helices (TM1-3) were prepared with biosynthetic fluorotryptophan incorporation. Interactions of each AR fragment with a high-affinity, 2,4,5-trifluorophenylalanine labeled apelin analogue were compared by 19F NMR. Distinct ranges of 19F chemical shifts for ligand and receptor provide unambiguous tracking of both species, with distinct binding behaviour observed for each AR fragment implying that AR55 is not sufficient to recapitulate the physiological binding event. Site-specific perturbation was also apparent for the apelin analogue as a function of substitution site, indicating an orientational binding preference. As a whole, this strategy of distinctive 19F labelling for ligand and receptor provides a relatively fast (i.e., employing 1D NMR experiments) and highly sensitive method to simultaneously and definitively track binding in both species.
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Affiliation(s)
- Jeffrey R Simmons
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Alexandre Murza
- Institut de Pharmacologie, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Pharmacology-Physiology, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Michael D Lumsden
- Department of Chemistry, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Calem Kenward
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Éric Marsault
- Institut de Pharmacologie, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
- Department of Pharmacology-Physiology, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Jan K Rainey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
- Department of Chemistry, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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6
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Onorato JM, Xu C, Chen XQ, Rose AV, Generaux C, Lentz K, Shipkova P, Arthur S, Hennan JK, Haskell R, Myers MC, Lawrence RM, Finlay HJ, Basso M, Bostwick J, Fernando G, Garcia R, Hellings S, Hsu MY, Zhang R, Zhao L, Gargalovic P. Linking (Pyr) 1apelin-13 pharmacokinetics to efficacy: Stabilization and measurement of a high clearance peptide in rodents. Anal Biochem 2018; 568:41-50. [PMID: 30605634 DOI: 10.1016/j.ab.2018.12.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/19/2018] [Accepted: 12/28/2018] [Indexed: 12/19/2022]
Abstract
Apelin, the endogenous ligand for the APJ receptor, has generated interest due to its beneficial effects on the cardiovascular system. Synthesized as a 77 amino acid preproprotein, apelin is post-translationally cleaved to a series of shorter peptides. Though (Pyr)1apelin-13 represents the major circulating form in plasma, it is highly susceptible to proteolytic degradation and has an extremely short half-life, making it challenging to quantify. Literature reports of apelin levels in rodents have historically been determined with commercial ELISA kits which suffer from a lack of selectivity, recognizing a range of active and inactive isoforms of apelin peptide. (Pyr)1apelin-13 has demonstrated beneficial hemodynamic effects in humans, and we wished to evaluate if similar effects could be measured in pre-clinical models. Despite development of a highly selective LC/MS/MS method, in rodent studies where (Pyr)1apelin-13 was administered exogenously the peptide was not detectable until a detailed stabilization protocol was implemented during blood collection. Further, the inherent high clearance of (Pyr)1apelin-13 required an extended release delivery system to enable chronic dosing. The ability to deliver sustained doses and stabilize (Pyr)1apelin-13 in plasma allowed us to demonstrate for the first time the link between systemic concentration of apelin and its pharmacological effects in animal models.
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Affiliation(s)
- Joelle M Onorato
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA.
| | - Carrie Xu
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Xue-Qing Chen
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Anne V Rose
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Claudia Generaux
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Kimberley Lentz
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Petia Shipkova
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Susan Arthur
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - James K Hennan
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Roy Haskell
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Michael C Myers
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - R Michael Lawrence
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Heather J Finlay
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Michael Basso
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Jeffrey Bostwick
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Gayani Fernando
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Ricardo Garcia
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Samuel Hellings
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Mei-Yin Hsu
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Rongan Zhang
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Lei Zhao
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
| | - Peter Gargalovic
- Drug Discovery, Bristol-Myers Squibb Company, Princeton, NJ, 08543-5400, USA
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7
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Shin K, Landsman M, Pelletier S, Alamri BN, Anini Y, Rainey JK. Proapelin is processed extracellularly in a cell line-dependent manner with clear modulation by proprotein convertases. Amino Acids 2018; 51:395-405. [PMID: 30430332 PMCID: PMC7101949 DOI: 10.1007/s00726-018-2674-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 10/28/2018] [Indexed: 12/15/2022]
Abstract
Apelin is a peptide hormone that binds to a class A GPCR (the apelin receptor/APJ) to regulate various bodily systems. Upon signal peptide removal, the resulting 55-residue isoform, proapelin/apelin-55, can be further processed to 36-, 17-, or 13-residue isoforms with length-dependent pharmacological properties. Processing was initially proposed to occur intracellularly. However, detection of apelin-55 in extracellular fluids indicates that extracellular processing may also occur. To test for this, apelin-55 was applied exogenously to HEK293A cells overexpressing proprotein convertase subtilisin kexin 3 (PCSK3), the only apelin processing enzyme identified thus far, and to differentiated 3T3-L1 adipocytes, which endogenously express apelin, PCSK3 and other proprotein convertases. Analysis of culture media constituents from each cell type by high performance liquid chromatography–mass spectrometry and western blot demonstrated a time-dependent decrease in apelin-55 levels. This decrease was partially, but not fully, attenuated by PCSK inhibitor treatment in both cell lines. Comparison of the resulting apelin-55-derived peptide profile between the two cell lines demonstrated distinct processing patterns, with apelin-36 production apparent in 3T3-L1 adipocytes vs. detection of the prodomain of a shorter isoform (likely the apelin-13 prodomain, observed after additional proteolytic processing) in PCSK3-transfected HEK293A cells. Extracellular processing of apelin, with distinct cell type dependence, provides an alternative mechanism to regulate isoform-mediated physiological effects of apelin.
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Affiliation(s)
- Kyungsoo Shin
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Michael Landsman
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Stephanie Pelletier
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Bader N Alamri
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, B3H 4R2, Canada.,Department of Obstetrics and Gynaecology, Dalhousie University, Halifax, NS, B3H 4R2, Canada.,Department of Medicine, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Younes Anini
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, B3H 4R2, Canada. .,Department of Obstetrics and Gynaecology, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
| | - Jan K Rainey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada. .,Department of Chemistry, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
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8
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Sarker M, Speckert M, Rainey JK. Bicelle composition-dependent modulation of phospholipid dynamics by apelin peptides 1. Biochem Cell Biol 2018; 97:325-332. [PMID: 30092142 DOI: 10.1139/bcb-2018-0172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Apelin peptides are cognate ligands for the apelin receptor, a G-protein-coupled receptor (GPCR). The apelinergic system plays critical roles in wide-ranging physiological activities including function and development of the central nervous and cardiovascular systems. Apelin is found in 13-55 residue isoforms in vivo, all of which share the C-terminal portion of the preproapelin precursor. Characterization of high-resolution structures and detergent micelle interactions of apelin-17 led to a two-step membrane-catalyzed binding and GPCR activation mechanism hypothesis recapitulated in longer isoforms. Here, we examine interactions of the apelin-13 and -17 isoforms with isotropic zwitterionic and mixed zwitterionic-anionic lipid bicelles to test for hallmarks of membrane catalysis in a more physiological membrane-mimetic environment than a micelle. Specifically, 1H and 31P relaxation and diffusion solution-state NMR techniques demonstrate that both apelin isoforms interact with both types of isotropic bicelles. Bicelle hydrodynamics were observed to be differentially modulated by apelin peptides, although these effects were minimal. Phospholipid headgroup 31P spin relaxation behaviour was, conversely, clearly perturbed. Perturbation of this nature was also observed in magnetically aligned bicelles by 31P solid-state NMR spectroscopy and spin relaxation experiments. This behaviour is consistent with an apelin-bicelle binding process allowing significant peptide mobility, facilitating membrane-catalyzed GPCR encounter.
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Affiliation(s)
- Muzaddid Sarker
- a Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Matt Speckert
- a Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Jan K Rainey
- a Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.,b Department of Chemistry, Dalhousie University, Halifax, NS B3H 4R2, Canada
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9
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Mandaliti W, Nepravishta R, Pica F, Vallebona PS, Garaci E, Paci M. Potential mechanism of thymosin-α1-membrane interactions leading to pleiotropy: experimental evidence and hypotheses. Expert Opin Biol Ther 2018; 18:33-42. [DOI: 10.1080/14712598.2018.1456527] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Walter Mandaliti
- Department of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Rome, Italy
| | - Ridvan Nepravishta
- Department of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Rome, Italy
- School of Pharmacy, East Anglia University, Norwich, UK
| | - Francesca Pica
- Department of Experimental Medicine and Surgery, University of Rome “Tor Vergata”, Rome, Italy
| | | | - Enrico Garaci
- San Raffaele Pisana Scientific Institute for Research, Hospitalization and Health Care, Rome, Italy
| | - Maurizio Paci
- Department of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Rome, Italy
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10
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Murza A, Trân K, Bruneau-Cossette L, Lesur O, Auger-Messier M, Lavigne P, Sarret P, Marsault É. Apelins, ELABELA, and their derivatives: Peptidic regulators of the cardiovascular system and beyond. Pept Sci (Hoboken) 2018. [DOI: 10.1002/pep2.24064] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Alexandre Murza
- Département de Pharmacologie et Physiologie, Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
- Institut de Pharmacologie de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
| | - Kien Trân
- Département de Pharmacologie et Physiologie, Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
- Institut de Pharmacologie de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
| | - Laurent Bruneau-Cossette
- Département de Pharmacologie et Physiologie, Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
- Institut de Pharmacologie de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
| | - Olivier Lesur
- Institut de Pharmacologie de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
- Département de Médecine, Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
| | - Mannix Auger-Messier
- Département de Médecine, Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
| | - Pierre Lavigne
- Institut de Pharmacologie de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
- Département de Biochimie, Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
| | - Philippe Sarret
- Département de Pharmacologie et Physiologie, Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
- Institut de Pharmacologie de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
| | - Éric Marsault
- Département de Pharmacologie et Physiologie, Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
- Institut de Pharmacologie de Sherbrooke; Sherbrooke Québec J1H 5N4 Canada
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11
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Abstract
Apelin and apela (ELABELA/ELA/Toddler) are two peptide ligands for a class A G-protein-coupled receptor named the apelin receptor (AR/APJ/APLNR). Ligand-AR interactions have been implicated in regulation of the adipoinsular axis, cardiovascular system, and central nervous system alongside pathological processes. Each ligand may be processed into a variety of bioactive isoforms endogenously, with apelin ranging from 13 to 55 amino acids and apela from 11 to 32, typically being cleaved C-terminal to dibasic proprotein convertase cleavage sites. The C-terminal region of the respective precursor protein is retained and is responsible for receptor binding and subsequent activation. Interestingly, both apelin and apela exhibit isoform-dependent variability in potency and efficacy under various physiological and pathological conditions, but most studies focus on a single isoform. Biophysical behavior and structural properties of apelin and apela isoforms show strong correlations with functional studies, with key motifs now well determined for apelin. Unlike its ligands, the AR has been relatively difficult to characterize by biophysical techniques, with most characterization to date being focused on effects of mutagenesis. This situation may improve following a recently reported AR crystal structure, but there are still barriers to overcome in terms of comprehensive biophysical study. In this review, we summarize the three components of the apelinergic system in terms of structure-function correlation, with a particular focus on isoform-dependent properties, underlining the potential for regulation of the system through multiple endogenous ligands and isoforms, isoform-dependent pharmacological properties, and biological membrane-mediated receptor interaction. © 2018 American Physiological Society. Compr Physiol 8:407-450, 2018.
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Affiliation(s)
- Kyungsoo Shin
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Calem Kenward
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jan K Rainey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
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12
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Apelin conformational and binding equilibria upon micelle interaction primarily depend on membrane-mimetic headgroup. Sci Rep 2017; 7:15433. [PMID: 29133807 PMCID: PMC5684411 DOI: 10.1038/s41598-017-14784-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/04/2017] [Indexed: 12/13/2022] Open
Abstract
Apelin is one of two peptide hormones that activate the apelin receptor (AR or APJ) to regulate the cardiovascular system, central nervous system, and adipoinsular axis. Here, we apply circular dichroism (CD) spectropolarimetry and nuclear magnetic resonance (NMR) spectroscopy to characterize the potential membrane binding by the two longest bioactive apelin isoforms, apelin-55 and -36, using membrane-mimetic dodecylphosphocholine (DPC), sodium dodecyl sulfate (SDS), and 1-palmitoyl-2-hydroxy-sn-glycero-3-[phospho-rac-(1-glycerol)] (LPPG) micelles. Pulsed field gradient diffusion NMR experiments demonstrated preferential interaction of both apelin-55 and -36 with anionic SDS and LPPG micelles over zwitterionic DPC micelles. Chemical shift perturbations and changes in ps-ns scale dynamics of apelin-55 in all micelles were similarly localized along the polypeptide backbone, demonstrating clear dependence upon detergent headgroup, while comparison of chemical shifts between apelin-55 and apelin-36 showed negligible differences indicative of highly similar modes of micelle interaction. Notably, the observed behaviour was consistent with an ensemble averaged pair of free and bound states in fast exchange on the NMR timescale proportional to the fraction of micelle-bound protein, implying a similar conformational equilibrium regardless of headgroup and tailgroup. Membrane catalysis of apelin-AR binding would thus give rise to analogous behaviour in the essential C-terminal region common to all apelin isoforms.
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Identification of a conformational heparin-recognition motif on the peptide hormone secretin: key role for cell surface binding. Biochem J 2017; 474:2249-2260. [PMID: 28536157 DOI: 10.1042/bcj20170035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/30/2017] [Accepted: 05/23/2017] [Indexed: 11/17/2022]
Abstract
Secretin is a peptide hormone that exerts pleiotropic physiological functions by specifically binding to its cognate membrane-bound receptor. The membrane catalysis model of peptide-receptor interactions states that soluble peptidic ligands initially interact with the plasma membrane. This interaction increases the local concentration and structures the peptide, enhancing the rate of receptor binding. However, this model does not consider the dense network of glycosaminoglycans (GAGs) at the surface of eukaryotic cells. These sulfated polysaccharide chains are known to sequester numerous proteic signaling molecules. In the present study, we evaluated the interaction between the peptide hormone secretin and sulfated GAGs and its contribution to cell surface binding. Using GAG-deficient cells and competition experiments with soluble GAGs, we observed by confocal microscopy and flow cytometry that GAGs mediate the sequestration of secretin at the cell surface. Isothermal titration calorimetry and surface plasmon resonance revealed that secretin binds to heparin with dissociation constants ranging between 0.9 and 4 μM. By designing secretin derivatives with a restricted conformational ensemble, we observed that this interaction is mediated by the presence of a specific conformational GAG-recognition motif that decorates the surface of the peptide upon helical folding. The present study identifies secretin as a novel GAG-binding polypeptide and opens new research direction on the functional role of GAGs in the biology of secretin.
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Bioactivity of the putative apelin proprotein expands the repertoire of apelin receptor ligands. Biochim Biophys Acta Gen Subj 2017; 1861:1901-1912. [PMID: 28546009 DOI: 10.1016/j.bbagen.2017.05.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/20/2017] [Accepted: 05/19/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Apelin is a peptide ligand for a class A G-protein coupled receptor called the apelin receptor (AR or APJ) that regulates angiogenesis, the adipoinsular axis, and cardiovascular functions. Apelin has been shown to be bioactive as 13, 17, and 36 amino acid isoforms, C-terminal fragments of the putatively inactive 55-residue proprotein (proapelin or apelin-55). Although intracellular proprotein processing has been proposed, isolation of apelin-55 from colostrum and milk demonstrates potential for secretion prior to processing and the possibility of proapelin-AR interaction. METHODS Apelin isoform activity and potency were compared by an In-Cell Western™ assay for ERK phosphorylation using a stably AR-transfected HEK293A cell line. Conformational comparison of apelin isoforms was carried out by circular dichroism and heteronuclear solution-state nuclear magnetic resonance spectroscopy. RESULTS Apelin-55 is shown to activate the AR, with similar maximum ERK phophorylation response and potency to the shorter isoforms except for apelin-13, which exhibited a greater potency. Correlating to this shared activity, highly similar conformations are exhibited in all apelin isoforms for the shared C-terminal region responsible for receptor binding and activation. CONCLUSIONS AR activation by all apelin isoforms likely hinges upon shared conformation and dynamics in the C-terminus, with apelin-55 providing an alternative bioactive isoform despite the addition of 19N-terminal residues relative to apelin-36. GENERAL SIGNIFICANCE Beyond providing novel insight into the physiology of this system, re-annotation of proapelin to the bioactive apelin-55 isoform adds to the molecular toolkit for dissection of apelin-AR interactions and expands the repertoire of therapeutic targets for the apelinergic system.
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Patterson RE, Weatherbee-Martin N, Rainey JK. Pyrene-Apelin Conjugation Modulates Fluorophore- and Peptide-Micelle Interactions. J Phys Chem B 2017; 121:4768-4777. [PMID: 28414462 DOI: 10.1021/acs.jpcb.7b02376] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bioactive apelin peptide forms ranging in length from 12 to 55 amino acids bind to and activate the apelin receptor (AR or APJ), a class A G-protein coupled receptor. Apelin-12, -17, and -36 isoforms, named according to length, with an additional N-terminal cysteine residue allowed for regiospecific and efficient conjugation of pyrene maleimide. Through steady-state fluorescence spectroscopy, the emission properties of pyrene in aqueous buffer were compared to those of the pyrene-apelin conjugates both without and with zwitterionic or anionic micelles. Pyrene photophysics are consistent with an expected partitioning into the hydrophobic micellar cores, while pyrene-apelin conjugation prevented this partitioning. Apelin, conversely, is expected to preferentially interact with anionic micelles; pyrene-apelin conjugates appear to lose preferential interaction. Finally, Förster resonance energy transfer between pyrene and tryptophan residues in the N-terminal tail and first transmembrane segment (the AR55 construct, comprising residues 1-55 of the AR) was consistent with efficient nonspecific pyrene-apelin conjugate binding to micelles rather than direct, specific apelin-AR55 binding. This approach provides a versatile fluorophore conjugation strategy for apelin, particularly valuable given that even a highly hydrophobic fluorophore is not deleterious to peptide behavior in membrane-mimetic micellar systems.
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Affiliation(s)
- Robin E Patterson
- Departments of †Biochemistry & Molecular Biology and ‡Chemistry, Dalhousie University , Halifax, Nova Scotia B3H 4R2, Canada
| | - Nathan Weatherbee-Martin
- Departments of †Biochemistry & Molecular Biology and ‡Chemistry, Dalhousie University , Halifax, Nova Scotia B3H 4R2, Canada
| | - Jan K Rainey
- Departments of †Biochemistry & Molecular Biology and ‡Chemistry, Dalhousie University , Halifax, Nova Scotia B3H 4R2, Canada
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16
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Huang SK, Shin K, Sarker M, Rainey JK. Apela exhibits isoform- and headgroup-dependent modulation of micelle binding, peptide conformation and dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:767-778. [PMID: 28132903 DOI: 10.1016/j.bbamem.2017.01.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/13/2017] [Accepted: 01/25/2017] [Indexed: 10/20/2022]
Abstract
Apela (also referred to as ELABELA and toddler) is a peptide hormone that activates the apelin receptor (AR or APJ) to regulate cardiovascular system development and function. Here, we report the first biophysical characterization of three apela isoforms, apela-54, -32, and -11, alongside a monomeric C1S-apela-11 mutant, using circular dichroism (CD) spectropolarimetry and nuclear magnetic resonance (NMR) spectroscopy. The behaviour of apela-54 is consistent with a preprotein containing a hydrophobic, N-terminal signal peptide. The potential for apela-membrane binding, leading to membrane catalyzed interactions with AR, was tested comprehensively for apela-32 and -11 in the presence of membrane-mimetic dodecylphosphocholine (DPC), sodium dodecyl sulfate (SDS), and 1-palmitoyl-2-hydroxy-sn-glycero-3-[phospho-rac-(1-glycerol)] (LPPG) micelles. According to pulsed-field gradient diffusion NMR experiments, apela-32 interacts with all three micelles. Chemical shift perturbations indicate widespread interactions along apela, with DPC and LPPG micelles inducing short segments with α-helical character at distinct regions. Consistent with these data, ps-ns dynamics along the peptide backbone appear decreased in the presence of micelles. Apela-11 and C1S-apela-11, alternatively, interact preferentially with SDS and LPPG micelles, promoting β-turn character observable by CD. Distinct differences in membrane-interaction propensity are therefore apparent both as a function of apela isoform and of detergent headgroup. These results imply the potential for cell membrane involvement in apela-AR recognition and binding, with the implication that membrane catalysis has distinct functional and regulatory roles throughout the apelinergic system.
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Affiliation(s)
- Shuya K Huang
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Kyungsoo Shin
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Muzaddid Sarker
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Jan K Rainey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
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17
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Preu J, Tiefenauer L, Gutberlet T. Adhesion ability of angiotensin II with model membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:195-200. [PMID: 27865700 DOI: 10.1016/j.bbamem.2016.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 11/14/2016] [Accepted: 11/15/2016] [Indexed: 01/08/2023]
Abstract
The octa-peptide angiotensin II (Ang II, (H2NAspArgValTyrIleHisProPheCOOH)) is one of the key player on blood pressure regulation in mammals. Predominantly binding to the Angiotensin type 1 and 2 receptors, the hormone is one of several peptide ligands binding to G protein coupled receptors (GPCR). The active hormone derives from a high molecular weight precursor sequentially cleaved by the proteases renin and the angiotensin converting enzyme (ACE). The chemical nature of the amino acid sequence has an impact on the behavior in the proximity of membranes, demonstrated using different membrane model systems and biophysical methods. Applying electrochemical impedance spectroscopy and small angle X-ray scattering a detailed view on the adhesion of the peptide with model membrane surfaces was performed. The role of specific amino acids involved in the interaction with the phospholipid head group were investigated and, studying a truncated version of Ang II, Ang (1-7), the key role of the C-terminal phenylalanine was proven. Truncation of the C-terminal amino acid abolishes the binding of the peptide to the membrane surface. A shift in pH, altering the protonation state of the central histidine residue impairs the adhesion of Ang II.
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Affiliation(s)
- Julia Preu
- Membrane Biophysics Group, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| | - Louis Tiefenauer
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen PSI, Switzerland
| | - Thomas Gutberlet
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Garching, Germany
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18
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Nepravishta R, Mandaliti W, Vallebona PS, Pica F, Garaci E, Paci M. Mechanism of Action of Thymosinα1: Does It Interact with Membrane by Recognition of Exposed Phosphatidylserine on Cell Surface? A Structural Approach. VITAMINS AND HORMONES 2016; 102:101-19. [PMID: 27450732 DOI: 10.1016/bs.vh.2016.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Thymosinα1 is a peptidic hormone with pleiotropic activity, which is used in the therapy of several diseases. It is unstructured in water solution and interacts with negative regions of micelles and vesicles assuming two tracts of helical conformation with a structural flexible break in between. The studies of the interaction of Thymosinα1 with micelles of mixed dipalmitoylphosphatidylcholine and sodium dodecylsulfate and vesicles with mixed dipalmitoylphosphatidylcholine/dipalmitoylphosphatidylserine, the latter the negative component of the membranes, by (1)H and natural abundance (15)N NMR are herewith reported, reviewed, and discussed. The results indicate that the preferred interactions are those where the surface is negatively charged due to sodium dodecylsulfate or due to the presence of dipalmitoylphosphatidylserine exposed on the surface. In fact the unbalance of dipalmitoylphosphatidylserine on the cellular surface is an important phenomenon present in pathological conditions of cells. Moreover, the direct interaction of Thymosinα1 with K562 cells presenting an overexposure of phosphatidylserine as a consequence of resveratrol-induced apoptosis was carried out.
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Affiliation(s)
- R Nepravishta
- University of Rome "Tor Vergata", Rome, Italy; Faculty of Pharmacy Catholic University "Our Lady of Good Counsel", Tirane, Albania
| | - W Mandaliti
- University of Rome "Tor Vergata", Rome, Italy
| | | | - F Pica
- University of Rome "Tor Vergata", Rome, Italy
| | - E Garaci
- University of Rome "Tor Vergata", Rome, Italy; San Raffaele Pisana Scientific Institute for Research, Hospitalization and Health Care, Rome, Italy
| | - M Paci
- University of Rome "Tor Vergata", Rome, Italy.
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19
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Mandaliti W, Nepravishta R, Sinibaldi Vallebona P, Pica F, Garaci E, Paci M. Thymosin α1 Interacts with Exposed Phosphatidylserine in Membrane Models and in Cells and Uses Serum Albumin as a Carrier. Biochemistry 2016; 55:1462-72. [DOI: 10.1021/acs.biochem.5b01345] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Walter Mandaliti
- Department
of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Ridvan Nepravishta
- Department
of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
- Department
of Chemical Pharmaceutical and Biomolecular Technologies, Faculty of Pharmacy Catholic University “Our Lady of Good Counsel”, Rr. D.
Hoxha, Tirane, Albania
| | - Paola Sinibaldi Vallebona
- Department
of Experimental Medicine and Surgery, University of Rome “Tor Vergata”, Via Montpellier 1, 00133 Rome, Italy
| | - Francesca Pica
- Department
of Experimental Medicine and Surgery, University of Rome “Tor Vergata”, Via Montpellier 1, 00133 Rome, Italy
| | - Enrico Garaci
- Department
of Experimental Medicine and Surgery, University of Rome “Tor Vergata”, Via Montpellier 1, 00133 Rome, Italy
- San
Raffaele Pisana Scientific Institute for Research, Hospitalization and Health Care, 00163 Rome, Italy
| | - Maurizio Paci
- Department
of Chemical Sciences and Technologies, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
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20
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Effects of Leucin-Enkephalins on Surface Characteristics and Morphology of Model Membranes Composed of Raft-Forming Lipids. J Membr Biol 2015; 249:229-38. [DOI: 10.1007/s00232-015-9862-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/28/2015] [Indexed: 12/21/2022]
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21
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Brame AL, Maguire JJ, Yang P, Dyson A, Torella R, Cheriyan J, Singer M, Glen RC, Wilkinson IB, Davenport AP. Design, characterization, and first-in-human study of the vascular actions of a novel biased apelin receptor agonist. Hypertension 2015; 65:834-40. [PMID: 25712721 PMCID: PMC4354462 DOI: 10.1161/hypertensionaha.114.05099] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Supplemental Digital Content is available in the text. [Pyr1]apelin-13 is an endogenous vasodilator and inotrope but is downregulated in pulmonary hypertension and heart failure, making the apelin receptor an attractive therapeutic target. Agonists acting at the same G-protein–coupled receptor can be engineered to stabilize different conformational states and function as biased ligands, selectively stimulating either G-protein or β-arrestin pathways. We used molecular dynamics simulations of apelin/receptor interactions to design cyclic analogues and identified MM07 as a biased agonist. In β-arrestin and internalization assays (G-protein–independent), MM07 was 2 orders of magnitude less potent than [Pyr1]apelin-13. In a G-protein–dependent saphenous vein contraction assay, both peptides had comparable potency (pD2:[Pyr1]apelin-13 9.93±0.24; MM07 9.54±0.42) and maximum responses with a resulting bias for MM07 of ≈350- to 1300-fold for the G-protein pathway. In rats, systemic infusions of MM07 (10-100nmol) caused a dose-dependent increase in cardiac output that was significantly greater than the response to [Pyr1]apelin-13. Similarly, in human volunteers, MM07 produced a significant dose-dependent increase in forearm blood flow with a maximum dilatation double that is seen with [Pyr1]apelin-13. Additionally, repeated doses of MM07 produced reproducible increases in forearm blood flow. These responses are consistent with a more efficacious action of the biased agonist. In human hand vein, both peptides reversed an established norepinephrine constrictor response and significantly increased venous flow. Our results suggest that MM07 acting as a biased agonist at the apelin receptor can preferentially stimulate the G-protein pathway, which could translate to improved efficacy in the clinic by selectively stimulating vasodilatation and inotropic actions but avoiding activating detrimental β-arrestin–dependent pathways.
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Affiliation(s)
- Aimee L Brame
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Janet J Maguire
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Peiran Yang
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Alex Dyson
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Rubben Torella
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Joseph Cheriyan
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Mervyn Singer
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Robert C Glen
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Ian B Wilkinson
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.)
| | - Anthony P Davenport
- From the Clinical Pharmacology Unit, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, UK (A.L.B., J.J.M., P.Y., J.C., I.B.W., A.P.D.); Bloomsbury Institute of Intensive Care Medicine, University College London, London, UK (A.D., M.S.); and Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of. Cambridge, Cambridge, UK (R.T., R.C.G.).
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Pisarenko OI, Shulzhenko VS, Pelogeykina YA, Studneva IM. Enhancement of crystalloid cardioplegic protection by structural analogs of apelin-12. J Surg Res 2014; 194:18-24. [PMID: 25491175 DOI: 10.1016/j.jss.2014.11.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 10/29/2014] [Accepted: 11/05/2014] [Indexed: 01/09/2023]
Abstract
BACKGROUND C-terminal fragments of adipokine apelin are able to attenuate myocardial ischemia-reperfusion (I/R) injury, but whether their effects are manifested during cardioplegic arrest remain obscure. This study was designed to evaluate the efficacy of natural apelin-12 (H-Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Met-Pro-Phe-OH, A12) and its novel structural analogs (H-(N(α)Me)Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Nle-Pro-Phe-OH, AI, and N(G)-Arg(N(G)NO2)-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Nle-Pro-Phe-NH2, AII) as additives to crystalloid cardioplegia and explore benefits of early reperfusion with these peptides. METHODS Isolated working rat hearts subjected to normothermic global ischemia and further reperfusion were used. St. Thomas' Hospital cardioplegic solution No.2 (STH2) containing 140 μM A12, AI, or AII was infused for 5 min at 25 °C before ischemia. In separate series, peptide administration was used for 5 min after ischemia. Metabolic state of the hearts was evaluated by myocardial content of high energy phosphates and lactate. Lactate dehydrogenase (LDH) leakage was assessed in myocardial effluent on early reperfusion. RESULTS Addition of the peptides to STH2 enhanced functional and metabolic recovery of reperfused hearts compared with those of control (STH2 without additives). Cardioplegia with analog AII was the most effective and accompanied by a reduction of postischemic LDH leakage. Infusion of A12, AI, or AII after ischemia improved the majority indices of cardiac function and metabolic state of the heart by the end of reperfusion. However, the overall protective effect of the peptides was less than when they were added to STH2. CONCLUSIONS Enhancement of apelin bioavailability may minimize myocardial I/R damage during cardiac surgery. Structural analogs of A12 are promising components of clinical cardioplegic solutions.
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Affiliation(s)
- Oleg I Pisarenko
- Russian Cardiology Research and Production Complex, Moscow, Russia.
| | | | | | - Irina M Studneva
- Russian Cardiology Research and Production Complex, Moscow, Russia
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Chapman NA, Dupré DJ, Rainey JK. The apelin receptor: physiology, pathology, cell signalling, and ligand modulation of a peptide-activated class A GPCR. Biochem Cell Biol 2014; 92:431-40. [PMID: 25275559 DOI: 10.1139/bcb-2014-0072] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The apelin receptor (AR or APJ) is a class A (rhodopsin-like) G-protein-coupled receptor with wide distribution throughout the human body. Activation of the AR by its cognate peptide ligand, apelin, induces diverse physiological effects including vasoconstriction and dilation, strengthening of heart muscle contractility, angiogenesis, and regulation of energy metabolism and fluid homeostasis. Recently, another endogenous peptidic activator of the AR, Toddler/ELABELA, was identified as having a crucial role in zebrafish (Danio rerio) embryonic development. The AR is also implicated in pathologies including cardiovascular disease, diabetes, obesity, and cancer, making it a promising therapeutic target. Despite its established importance, the precise roles of AR signalling remain poorly understood. Moreover, little is known about the mechanisms of peptide-AR activation. Additional complexity arises from modulation of the AR by 2 endogenous peptide ligands, both with multiple bioactive isoforms of variable length and distribution. The various apelin and Toddler/ELABELA isoforms may also produce distinct cellular effects. Further complexity arises through formation of functionally distinct heterodimers between the AR and other G-protein-coupled receptors. This minireview outlines key (patho)physiological actions of the AR, addresses what is known about signal transduction downstream of AR activation, and concludes by discussing unique properties of the endogenous peptidic ligands of the AR.
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Affiliation(s)
- Nigel A Chapman
- a Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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Pisarenko OI, Serebryakova LI, Studneva IM, Pelogeykina YA, Tskitishvili OV, Bespalova ZD, Sidorova MV, Az'muko AA, Khatri DN, Pal'keeva ME, Molokoedov AS. Effects of structural analogues of apelin-12 in acute myocardial infarction in rats. J Pharmacol Pharmacother 2013; 4:198-203. [PMID: 23960425 PMCID: PMC3746303 DOI: 10.4103/0976-500x.114600] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Objective: To examine cardioprotective effects of Ρ-terminal fragment of adipokine apelin-12 (A12), its novel structural analogue [MeArg1, NLe10]-A12 (I), and [d-Ala12]-A12 (II), a putative antagonist of APJ receptor, employing in vivo model of ischemia/reperfusion (I/R) injury. Materials and Methods: Peptides were synthesized by the automatic solid phase method using Fmoc technology. Anesthetized open-chest male Wistar rats were subjected to left anterior descending (LAD) coronary artery occlusion and coronary reperfusion. Hemodynamic variables and electrocardiogram (ECG) were monitored throughout the experiment. Myocardial injury was assessed by infarct size (IS), activity of necrosis markers in plasma, and metabolic state of the area at risk (AAR). Results: Intravenous injection of A12, I, or II at the onset of reperfusion led to a transient reduction of the mean arterial pressure. A12 or I administration decreased the percent ratio of IS/AAR by 40% and 30%, respectively, compared with control animals which received saline. Both peptides improved preservation of high-energy phosphates, reduced lactate accumulation in the AAR, and lowered CK-MB and LDH activities in plasma at the end of reperfusion compared with these indices in control. Treatment with II did not significantly affect either the IS/AAR, % ratio, or activities of both markers of necrosis compared with control. The overall metabolic protection of the AAR in the treated groups increased in the following rank: II < A12 < I. Conclusions: The structural analogue of apelin-12 [MeArg1, NLe10]-A12 may be a promising basis to create a new drug for the treatment of acute coronary syndrome.
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Affiliation(s)
- Oleg I Pisarenko
- Russian Cardiology Research-and-Production Complex, Institute of Experimental Cardiology, Moscow, Russian Federation
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Hocking HG, Zangger K, Madl T. Studying the structure and dynamics of biomolecules by using soluble paramagnetic probes. Chemphyschem 2013; 14:3082-94. [PMID: 23836693 PMCID: PMC4171756 DOI: 10.1002/cphc.201300219] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Indexed: 12/20/2022]
Abstract
Characterisation of the structure and dynamics of large biomolecules and biomolecular complexes by NMR spectroscopy is hampered by increasing overlap and severe broadening of NMR signals. As a consequence, the number of available NMR spectroscopy data is often sparse and new approaches to provide complementary NMR spectroscopy data are needed. Paramagnetic relaxation enhancements (PREs) obtained from inert and soluble paramagnetic probes (solvent PREs) provide detailed quantitative information about the solvent accessibility of NMR-active nuclei. Solvent PREs can be easily measured without modification of the biomolecule; are sensitive to molecular structure and dynamics; and are therefore becoming increasingly powerful for the study of biomolecules, such as proteins, nucleic acids, ligands and their complexes in solution. In this Minireview, we give an overview of the available solvent PRE probes and discuss their applications for structural and dynamic characterisation of biomolecules and biomolecular complexes.
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Affiliation(s)
- Henry G Hocking
- Chair of Biomolecular NMR, Department Chemie, Technische Universität München, 85747 Garching (Germany); Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg (Germany)
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Langelaan DN, Reddy T, Banks AW, Dellaire G, Dupré DJ, Rainey JK. Structural features of the apelin receptor N-terminal tail and first transmembrane segment implicated in ligand binding and receptor trafficking. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:1471-83. [PMID: 23438363 DOI: 10.1016/j.bbamem.2013.02.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 01/17/2013] [Accepted: 02/13/2013] [Indexed: 12/20/2022]
Abstract
G-protein coupled receptors (GPCRs) comprise a large family of membrane proteins with rich functional diversity. Signaling through the apelin receptor (AR or APJ) influences the cardiovascular system, central nervous system and glucose regulation. Pathophysiological involvement of apelin has been shown in atherosclerosis, cancer, human immunodeficiency virus-1 (HIV-1) infection and obesity. Here, we present the high-resolution nuclear magnetic resonance (NMR) spectroscopy-based structure of the N-terminus and first transmembrane (TM) segment of AR (residues 1-55, AR55) in dodecylphosphocholine micelles. AR55 consists of two disrupted helices, spanning residues D14-K25 and A29-R55(1.59). Molecular dynamics (MD) simulations of AR built from a hybrid of experimental NMR and homology model-based restraints allowed validation of the AR55 structure in the context of the full-length receptor in a hydrated bilayer. AR55 structural features were functionally probed using mutagenesis in full-length AR through monitoring of apelin-induced extracellular signal-regulated kinase (ERK) phosphorylation in transiently transfected human embryonic kidney (HEK) 293A cells. Residues E20 and D23 form an extracellular anionic face and interact with lipid headgroups during MD simulations in the absence of ligand, producing an ideal binding site for a cationic apelin ligand proximal to the membrane-water interface, lending credence to membrane-catalyzed apelin-AR binding. In the TM region of AR55, N46(1.50) is central to a disruption in helical character. G42(1.46), G45(1.49) and N46(1.50), which are all involved in the TM helical disruption, are essential for proper trafficking of AR. In summary, we introduce a new correlative NMR spectroscopy and computational biochemistry methodology and demonstrate its utility in providing some of the first high-resolution structural information for a peptide-activated GPCR TM domain.
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Affiliation(s)
- David N Langelaan
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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27
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Hohlweg W, Kosol S, Zangger K. Determining the orientation and localization of membrane-bound peptides. Curr Protein Pept Sci 2012; 13:267-79. [PMID: 22044140 PMCID: PMC3394173 DOI: 10.2174/138920312800785049] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 10/01/2011] [Accepted: 10/10/2011] [Indexed: 01/06/2023]
Abstract
Many naturally occurring bioactive peptides bind to biological membranes. Studying and elucidating the mode of interaction is often an essential step to understand their molecular and biological functions. To obtain the complete orientation and immersion depth of such compounds in the membrane or a membrane-mimetic system, a number of methods are available, which are separated in this review into four main classes: solution NMR, solid-state NMR, EPR and other methods. Solution NMR methods include the Nuclear Overhauser Effect (NOE) between peptide and membrane signals, residual dipolar couplings and the use of paramagnetic probes, either within the membrane-mimetic or in the solvent. The vast array of solid state NMR methods to study membrane-bound peptide orientation and localization includes the anisotropic chemical shift, PISA wheels, dipolar waves, the GALA, MAOS and REDOR methods and again the use of paramagnetic additives on relaxation rates. Paramagnetic additives, with their effect on spectral linewidths, have also been used in EPR spectroscopy. Additionally, the orientation of a peptide within a membrane can be obtained by the anisotropic hyperfine tensor of a rigidly attached nitroxide label. Besides these magnetic resonance techniques a series of other methods to probe the orientation of peptides in membranes has been developed, consisting of fluorescence-, infrared- and oriented circular dichroism spectroscopy, colorimetry, interface-sensitive X-ray and neutron scattering and Quartz crystal microbalance.
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Affiliation(s)
| | | | - Klaus Zangger
- Institute of Chemistry / Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria
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28
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Pisarenko OI, Pelogeykina YA, Bespalova ZD, Serebryakova LI, Sidorova MV, Az'muko AA, Khatri DN, Studneva IM, Pal'keeva ME, Tskitishvili OV, Molokoedov AS. Limitation of myocardial infarction by a structural analog of the peptide apelin-12. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2012; 443:65-67. [PMID: 22562669 DOI: 10.1134/s0012496612020044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Indexed: 05/31/2023]
Affiliation(s)
- O I Pisarenko
- Russian Cardiology Research and Production Complex, Ministry of Health and Social Development of the Russian Federation, Moscow, Russia
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29
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Pisarenko OI, Pelogeykina YA, Shulzhenko VS, Studneva IM. Nitric oxide synthase mediates the apelin-induced improvement of myocardial postischemic metabolic and functional recovery. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ojmip.2012.21001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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30
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Macaluso NJM, Pitkin SL, Maguire JJ, Davenport AP, Glen RC. Discovery of a competitive apelin receptor (APJ) antagonist. ChemMedChem 2011; 6:1017-23. [PMID: 21560248 DOI: 10.1002/cmdc.201100069] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 03/29/2011] [Indexed: 01/27/2023]
Abstract
The apelin receptor (APJ) is a class A G-protein-coupled receptor (GPCR) and is a putative target for the treatment of cardiovascular and metabolic diseases. Apelin-13 (NH₂-QRPRLSHKGPMPF-COOH) is a vasoactive peptide and one of the most potent endogenous inotropic agents identified to date. We report the design and discovery of a novel APJ antagonist. By using a bivalent ligand approach, we have designed compounds with two 'affinity' motifs and a short series of linker groups with different conformational and non-bonded interaction properties. One of these, cyclo(1-6)CRPRLC-KH-cyclo(9-14)CRPRLC is a competitive antagonist at APJ. Radioligand binding in CHO cells transfected with human APJ gave a K(i) value of 82 nM, competition binding in human left ventricle gave a K(D) value of 3.2 μM, and cAMP accumulation assays in CHO-K1-APJ cells gave a K(D) value of 1.32 μM.
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Affiliation(s)
- N J Maximilian Macaluso
- Unilever Centre for Molecular Sciences Informatics, Department of Chemistry, University of Cambridge, Lensfield Road CB2 1EW, Cambridge, UK
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Langelaan DN, Rainey JK. Membrane catalysis of peptide-receptor binding. Biochem Cell Biol 2010; 88:203-10. [PMID: 20453923 DOI: 10.1139/o09-129] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The membrane catalysis hypothesis states that a peptide ligand activates its target receptor after an initial interaction with the surrounding membrane. Upon membrane binding and interaction, the ligand is structured such that receptor binding and activation is encouraged. As evidence for this hypothesis, there are numerous studies concerning the conformation that peptides adopt in membrane mimetic environments. This mini-review analyzes the features of ligand peptides with an available high-resolution membrane-induced structure and a characterized membrane-binding region. At the peptide-membrane interface, both amphipathic helices and turn structures are commonly formed in peptide ligands and both hydrophobic and electrostatic interactions can be responsible for membrane binding. Apelin is the ligand to the G-protein coupled receptor (GPCR) named APJ, with various important physiological effects, which we have recently characterized both in solution and bound to anionic micelles. The structural changes that apelin undergoes when binding to micelles provide strong evidence for membrane catalysis of apelin-APJ interactions.
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Affiliation(s)
- David N Langelaan
- Department of Biochemistry & Molecular Biology, Dalhousie University, Tupper Medical Building, 5850 College Street, Halifax, NS B3H 1X5, Canada
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Göbl C, Dulle M, Hohlweg W, Grossauer J, Falsone SF, Glatter O, Zangger K. Influence of phosphocholine alkyl chain length on peptide-micelle interactions and micellar size and shape. J Phys Chem B 2010; 114:4717-24. [PMID: 20225847 DOI: 10.1021/jp9114089] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The interaction with biological membranes is of functional importance for many peptides and proteins. Structural studies on such membrane-bound biomacromolecules are often carried out in solutions containing small membrane-mimetic assemblies of detergent molecules. To investigate the influence of the hydrophobic chain length on the structure, diffusional and dynamical behavior of a peptide bound to micelles, we studied the binding of three peptides to n-phosphocholines with n ranging from 8 to 16. The peptides studied are the 15 residue antimicrobial peptide CM15, the 25-residue transmembrane helix 7 of yeast V-ATPase (TM7), and the 35-residue bacterial toxin LdrD. To keep the dimension of the peptide-membrane-mimetic assembly small, micelles are typically used when studying membrane-bound peptides and proteins, for example, by solution NMR spectroscopy. Since they are readily available in deuterated form most often sodium-dodecylsulfate (SDS) and dodecylphosphocholine (DPC) are used as the micelle-forming detergent. Using NMR, CD, and SAXS, we found that all phosphocholines studied form spherical micelles in the presence and absence of small bound peptides and the diameters of the micelles are basically unchanged upon peptide binding. The size of the peptide relative to the micelle determines to what extent the secondary structure can form. For small peptides (up to approximately 25 residues) the use of shorter chain phosphocholines is recommended for solution NMR studies due to the favorable spectral quality and since they are as well-structured as in DPC. In contrast, larger peptides are better structured in micelles formed by detergents with chain lengths longer than DPC.
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Affiliation(s)
- Christoph Göbl
- Department of Chemistry/Organic and Bioorganic Chemistry, University of Graz Heinrichstrasse 28, A-8010 Graz, Austria
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Macaluso NM, Glen R. Exploring the ‘RPRL’ Motif of Apelin-13 through Molecular Simulation and Biological Evaluation of Cyclic Peptide Analogues. ChemMedChem 2010; 5:1247-53. [DOI: 10.1002/cmdc.201000061] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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