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Madsen TD, Hansen LH, Hintze J, Ye Z, Jebari S, Andersen DB, Joshi HJ, Ju T, Goetze JP, Martin C, Rosenkilde MM, Holst JJ, Kuhre RE, Goth CK, Vakhrushev SY, Schjoldager KT. An atlas of O-linked glycosylation on peptide hormones reveals diverse biological roles. Nat Commun 2020; 11:4033. [PMID: 32820167 PMCID: PMC7441158 DOI: 10.1038/s41467-020-17473-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 07/02/2020] [Indexed: 12/17/2022] Open
Abstract
Peptide hormones and neuropeptides encompass a large class of bioactive peptides that regulate physiological processes like anxiety, blood glucose, appetite, inflammation and blood pressure. Here, we execute a focused discovery strategy to provide an extensive map of O-glycans on peptide hormones. We find that almost one third of the 279 classified peptide hormones carry O-glycans. Many of the identified O-glycosites are conserved and are predicted to serve roles in proprotein processing, receptor interaction, biodistribution and biostability. We demonstrate that O-glycans positioned within the receptor binding motifs of members of the neuropeptide Y and glucagon families modulate receptor activation properties and substantially extend peptide half-lives. Our study highlights the importance of O-glycosylation in the biology of peptide hormones, and our map of O-glycosites in this large class of biomolecules serves as a discovery platform for an important class of molecules with potential opportunities for drug designs.
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Affiliation(s)
- Thomas D Madsen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Lasse H Hansen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.,Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, DK-2100, Copenhagen O, Denmark
| | - John Hintze
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Zilu Ye
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Shifa Jebari
- Biofisika Institute (UPV/EHU, CSIC), Departamento de Bioquímica, Universidad del País Vasco, Bilbao, 48080, Spain
| | - Daniel B Andersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Hiren J Joshi
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Tongzhong Ju
- Office of Biotechnology Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Jens P Goetze
- Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, DK-2100, Copenhagen O, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Cesar Martin
- Office of Biotechnology Products, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Mette M Rosenkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Rune E Kuhre
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.,Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Christoffer K Goth
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Sergey Y Vakhrushev
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - Katrine T Schjoldager
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.
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2
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Dores RM, Baron AJ. Evolution of POMC: origin, phylogeny, posttranslational processing, and the melanocortins. Ann N Y Acad Sci 2011; 1220:34-48. [DOI: 10.1111/j.1749-6632.2010.05928.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
Proteases constitute one of the primary targets in drug discovery. In the present review, we focus on extracellular proteases (ECPs) because of their differential expression in many pathophysiological processes, including cancer, cardiovascular conditions, and inflammatory, pulmonary, and periodontal diseases. Many new ECP inhibitors are currently under clinical investigation and a significant increase in new therapies based on protease inhibition can be expected in the coming years. In addition to directly blocking the activity of a targeted protease, one can take advantage of differential expression in disease states to selectively deliver therapeutic or imaging agents. Recent studies in targeted drug development for the metalloproteases (matrix metalloproteinases, adamalysins, pappalysins, neprilysin, angiotensin-converting enzyme, metallocarboxypeptidases, and glutamate carboxypeptidase II), serine proteases (elastase, coagulation factors, tissue/urokinase plasminogen activator system, kallikreins, tryptase, dipeptidyl peptidase IV) and cysteine proteases (cathepsin B) are discussed herein.
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Affiliation(s)
- Mare Cudic
- Department of Chemistry & Biochemistry, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431 U.S.A
| | - Gregg B. Fields
- Department of Biochemistry, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229 U.S.A
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Anctil M. Chemical transmission in the sea anemone Nematostella vectensis: A genomic perspective. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2009; 4:268-289. [PMID: 20403752 DOI: 10.1016/j.cbd.2009.07.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 06/30/2009] [Accepted: 07/07/2009] [Indexed: 12/30/2022]
Abstract
The sequencing of the starlet sea anemone (Nematostella vectensis) genome provides opportunities to investigate the function and evolution of genes associated with chemical neurotransmission and hormonal signaling. This is of particular interest because sea anemones are anthozoans, the phylogenetically basal cnidarians least changed from the common ancestors of cnidarians and bilaterian animals, and because cnidarians are considered the most basal metazoans possessing a nervous system. This analysis of the genome has yielded 20 orthologues of enzymes and nicotinic receptors associated with cholinergic function, an even larger number of genes encoding enzymes, receptors and transporters for glutamatergic (28) and GABAergic (34) transmission, and two orthologues of purinergic receptors. Numerous genes encoding enzymes (14), receptors (60) and transporters (5) for aminergic transmission were identified, along with four adenosine-like receptors and one nitric oxide synthase. Diverse neuropeptide and hormone families are also represented, mostly with genes encoding prepropeptides and receptors related to varying closeness to RFamide (17) and tachykinin (14), but also galanin (8), gonadotropin-releasing hormones and vasopressin/oxytocin (5), melanocortins (11), insulin-like peptides (5), glycoprotein hormones (7), and uniquely cnidarian peptide families (44). Surprisingly, no muscarinic acetylcholine receptors were identified and a large number of melatonin-related, but not serotonin, orthologues were found. Phylogenetic tree construction and inspection of multiple sequence alignments reveal how evolutionarily and functionally distant chemical transmitter-related proteins are from those of higher metazoans.
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Affiliation(s)
- Michel Anctil
- Département de sciences biologiques and Centre de recherches en sciences neurologiques, Université de Montréal, Case postale 6128, Succursale Centre-Ville, Montréal, Québec, Canada H3C 3J7.
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5
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Zhang X, Che FY, Berezniuk I, Sonmez K, Toll L, Fricker LD. Peptidomics of Cpe(fat/fat) mouse brain regions: implications for neuropeptide processing. J Neurochem 2008; 107:1596-613. [PMID: 19014391 DOI: 10.1111/j.1471-4159.2008.05722.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Quantitative peptidomics was used to compare levels of peptides in wild type (WT) and Cpe(fat/fat) mice, which lack carboxypeptidase E (CPE) activity because of a point mutation. Six different brain regions were analyzed: amygdala, hippocampus, hypothalamus, prefrontal cortex, striatum, and thalamus. Altogether, 111 neuropeptides or other peptides derived from secretory pathway proteins were identified in WT mouse brain extracts by tandem mass spectrometry, and another 47 peptides were tentatively identified based on mass and other criteria. Most secretory pathway peptides were much lower in Cpe(fat/fat) mouse brain, relative to WT mouse brain, indicating that CPE plays a major role in their biosynthesis. Other peptides were only partially reduced in the Cpe(fat/fat) mice, indicating that another enzyme (presumably carboxypeptidase D) contributes to their biosynthesis. Approximately 10% of the secretory pathway peptides were present in the Cpe(fat/fat) mouse brain at levels similar to those in WT mouse brain. Many peptides were greatly elevated in the Cpe(fat/fat) mice; these peptide processing intermediates with C-terminal Lys and/or Arg were generally not detectable in WT mice. Taken together, these results indicate that CPE contributes, either directly or indirectly, to the production of the majority of neuropeptides.
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Affiliation(s)
- Xin Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Pantoja-Uceda D, Arolas JL, García P, López-Hernández E, Padró D, Aviles FX, Blanco FJ. The NMR Structure and Dynamics of the Two-Domain Tick Carboxypeptidase Inhibitor Reveal Flexibility in Its Free Form and Stiffness upon Binding to Human Carboxypeptidase B. Biochemistry 2008; 47:7066-78. [DOI: 10.1021/bi800403m] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David Pantoja-Uceda
- Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain, NMR Group, Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain, Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain, and Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Spain
| | - Joan L. Arolas
- Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain, NMR Group, Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain, Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain, and Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Spain
| | - Pascal García
- Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain, NMR Group, Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain, Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain, and Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Spain
| | - Eva López-Hernández
- Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain, NMR Group, Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain, Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain, and Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Spain
| | - Daniel Padró
- Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain, NMR Group, Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain, Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain, and Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Spain
| | - Francesc X. Aviles
- Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain, NMR Group, Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain, Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain, and Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Spain
| | - Francisco J. Blanco
- Instituto de Química-Física Rocasolano, CSIC, Serrano 119, 28006 Madrid, Spain, NMR Group, Structural Biology and Biocomputing Programme, Centro Nacional de Investigaciones Oncológicas, CNIO, Melchor Fernández Almagro 3, 28029 Madrid, Spain, Institut de Biotecnologia i Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain, and Structural Biology Unit, CIC bioGUNE, Parque Tecnológico de Bizkaia, Edificio 800, 48160 Derio, Spain
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7
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Cunha GS, Ribeiro JL, Oliveira AR. Níveis de beta-endorfina em resposta ao exercício e no sobretreinamento. ACTA ACUST UNITED AC 2008; 52:589-98. [DOI: 10.1590/s0004-27302008000400004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 03/28/2008] [Indexed: 11/22/2022]
Abstract
O sobretreinamento (ST) é um fenômeno esportivo complexo e multifatorial; e atualmente não existe nenhum marcador independente que possa diagnosticá-lo. Interessantemente, alguns sintomas do ST apresentam relação com os efeitos da b-endorfina (b-end1-31). Alguns de seus efeitos são importantes para o treinamento, como analgesia, maior tolerância ao lactato e euforia do exercício. Esses efeitos podem ser revertidos por destreinamento ou por ST, ocasionando diminuição no desempenho, redução da tolerância à carga e depressão. O exercício físico é o principal estímulo da b-end1-31, pois sua secreção é volume/intensidade dependente, tanto para exercícios aeróbios quanto anaeróbios. No entanto, o treinamento excessivo pode diminuir suas concentrações, alterando assim seus efeitos benéficos para o treinamento. Portanto, a b-end1-31 poderia ser utilizada como um marcador adicional de ST, principalmente porque seus efeitos apresentam extensa relação com os sintomas do ST.
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Boonen K, Landuyt B, Baggerman G, Husson SJ, Huybrechts J, Schoofs L. Peptidomics: The integrated approach of MS, hyphenated techniques and bioinformatics for neuropeptide analysis. J Sep Sci 2008; 31:427-45. [DOI: 10.1002/jssc.200700450] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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9
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Boonen K, Baggerman G, D'Hertog W, Husson SJ, Overbergh L, Mathieu C, Schoofs L. Neuropeptides of the islets of Langerhans: a peptidomics study. Gen Comp Endocrinol 2007; 152:231-41. [PMID: 17559849 DOI: 10.1016/j.ygcen.2007.05.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Revised: 04/19/2007] [Accepted: 05/01/2007] [Indexed: 10/23/2022]
Abstract
Neuropeptides from the endocrine pancreas (the islets of Langerhans) play an important role in the regulation of blood glucose levels. Therefore, our aim is to identify the "peptidome" (the in vivo peptide profile at a certain time) of the pancreatic islets, which is beneficial for medical progress related to the treatment of diabetes. So far, there are few neuropeptides isolated and sequenced from the endocrine pancreas and mainly in situ hybridisation and immunocytochemical techniques have been used to demonstrate the occurrence of peptides in the pancreas. These techniques do not allow for unequivocal identification of peptides. In contrary, mass spectrometry identifies peptides unambiguously. We have analysed the peptidome of the islets using peptidomics, i.e. a combination of liquid chromatography, mass spectrometry and bioinformatics. We are able to identify the peptidome of islets extracts. We not only confirm the presence of peptides with a well-known effect on blood glucose levels, but also identify new peptides, which are unknown to affect blood glucose levels.
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Affiliation(s)
- Kurt Boonen
- Laboratory of Developmental Physiology, Genomics and Proteomics, KU Leuven, Belgium.
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Abstract
Neuropeptides are neurotransmitters and modulators distributed in the central nervous system (CNS) and peripheral nervous system. Their abnormalities cause neurological and mental diseases. Neuropeptidases are enzymes crucial for the biosynthesis and biodegradation of neuropeptides. We here focus on the peptidases involved in the metabolism of the well-studied opioid peptides. Bioactive enkephalins are formed from propeptides by processing enzymes—prohormone thiol protease, prohormone convertase 1 and 2 (PC 1 and 2), carboxypeptidase H/E, and Arg/Lys aminopeptidase. After they exert their biological effects, enkephalins are likely to be inactivated by degrading enzymes—angiotensin-converting enzyme (ACE), aminopeptidase N (APN), puromycin-sensitive aminopeptidase (PSA), and endopeptidase 24.11. Recently, a neuron-specific aminopeptidase (NAP), which was a putative enkephalin-inactivating enzyme at the synapses, was found. Neuropeptidases are useful drug targets and their inhibitors can be therapeutic. Synthetic anti-enkephalinases and anti-aminopeptidases are being developed. They are potent analgesics but have fewer side effects than the opiates.
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Affiliation(s)
- Abel Lajtha
- grid.250263.00000000121894777Center for Neurochemistry, Nathan S. Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, Newyork, 10962, USA
| | - Naren Banik
- grid.259828.c0000000121893475Department of Neurosciences Division of Neurology, Medical University of South Carolina, 96 Jonathan Lucas Street Suite 309, Charleston, SC 29425, USA
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11
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Fricker LD, Lim J, Pan H, Che FY. Peptidomics: identification and quantification of endogenous peptides in neuroendocrine tissues. MASS SPECTROMETRY REVIEWS 2006; 25:327-44. [PMID: 16404746 DOI: 10.1002/mas.20079] [Citation(s) in RCA: 170] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Neuropeptides perform a large variety of functions as intercellular signaling molecules. While most proteomic studies involve digestion of the proteins with trypsin or other proteases, peptidomics studies usually analyze the native peptide forms. Neuropeptides can be studied by using mass spectrometry for identification and quantitation. In many cases, mass spectrometry provides an understanding of the precise molecular form of the native peptide, including post-translational cleavages and other modifications. Quantitative peptidomics studies generally use differential isotopic tags to label two sets of extracted peptides, as done with proteomic studies, except that the Cys-based reagents typically used for quantitation of proteins are not suitable because most peptides lack Cys residues. Instead, a number of amine-specific labels have been created and some of these are useful for peptide quantitation by mass spectrometry. In this review, peptidomics techniques are discussed along with the major findings of many recent studies and future directions for the field.
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Affiliation(s)
- Lloyd D Fricker
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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12
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Abstract
The Arabidopsis BRS1 gene encodes a serine carboxypeptidase II-like protein. Its biological role in the brassinosteroid signaling pathway was first established by its capability to specifically suppress a weak brassinosteroid insensitive 1 (bri1) allele, bri1-5, when overexpressed. To gain additional insights into the molecular mechanisms of BRS1 function, the subcellular localization and the biochemical characteristics of BRS1 were determined by using transgenic plants harboring a 35S-BRS1-GFP construct and fusion proteins purified from 35S-BRS1-FLAG transgenic plants. The BRS1-GFP protein was mainly secreted and accumulated in the extracellular space. Immunological data suggest that BRS1 is proteolytically processed by an unknown endoproteinase in planta. Affinity-purified BRS1-FLAG from transgenic plants show strong hydrolytic activity with a broad P1 substrate preference including basic and hydrophobic groups on either side of the scissile bond. The hydrolytic activity of BRS1 can be strongly inhibited by a serine protease inhibitor, phenylmethylsulfonyl fluoride. The pH and temperature optima for the hydrolytic activity of BRS1 are pH 5.5 and 50 degrees C, respectively. These data demonstrate that BRS1 is a secreted and active serine carboxypeptidase, consistent with the hypothesis suggested by our previous genetic evidence that BRS1 may process a protein involved in an early event in the BRI1 signaling pathway.
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Affiliation(s)
- Aifen Zhou
- Department of Botany and Microbiology, University of Oklahoma, Norman, Oklahoma 73019, USA
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Che FY, Biswas R, Fricker LD. Relative quantitation of peptides in wild-type and Cpe(fat/fat) mouse pituitary using stable isotopic tags and mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2005; 40:227-237. [PMID: 15706630 DOI: 10.1002/jms.742] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cpe(fat/fat) mice have a point mutation in the coding region of the carboxypeptidase E gene that renders the enzyme inactive. As a result, these mice have reduced levels of several neuropeptides and greatly increased levels of the peptide processing intermediates that contain C-terminal basic residues. However, previous studies examined a relatively small number of neuropeptides. In the present study, we used a quantitative peptidomics approach with stable isotopic labels to examine the levels of pituitary peptides in Cpe(fat/fat) mice relative to wild-type mice. Pituitary extracts from mutant and wild type mice were labeled with the stable isotopic label [3-(2,5-dioxopyrrolidin-1-yloxycarbonyl)propyl]trimethylammonium chloride containing nine atoms of hydrogen or deuterium. Then, the two samples were pooled and analyzed by liquid chromatography/mass spectrometry (LC/MS). The relative abundance of peptides was determined from a comparison of the intensities of the heavy and light peaks. Altogether, 72 peptides were detected in the Cpe(fat/fat) and/or wild-type mouse pituitary extracts of which 53 were identified by MS/MS sequencing. Several peptides identified in this analysis represent previously undescribed post-translational processing products of known pituitary prohormones. Of the 72 peptides detected in pituitary, 17 were detected only in the Cpe(fat/fat) mouse extracts; these represent peptide processing intermediates containing C-terminal basic residues. The peptides common to both Cpe(fat/fat) and wild-type mice were generally present at 2-5-fold lower levels in the Cpe(fat/fat) mouse pituitary extracts, although some peptides were present at equal levels and one peptide (acetyl beta-endorphin 1-31) was increased approximately 7-fold in the Cpe(fat/fat) pituitary extracts. In contrast, acetyl beta-endorphin 1-26 was present at approximately 10-fold lower levels in the Cpe(fat/fat) pituitary, compared with wild-type mice. The finding that many peptides are substantially decreased in Cpe(fat/fat) pituitary is consistent with the broad role for carboxypeptidase E in the biosynthesis of numerous neuropeptides.
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Affiliation(s)
- Fa-Yun Che
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Zhou A, Minami M, Zhu X, Bae S, Minthorne J, Lan J, Xiong ZG, Simon RP. Altered biosynthesis of neuropeptide processing enzyme carboxypeptidase E after brain ischemia: molecular mechanism and implication. J Cereb Blood Flow Metab 2004; 24:612-22. [PMID: 15181368 DOI: 10.1097/01.wcb.0000118959.03453.17] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In this study, using both in vivo and in vitro ischemia models, the authors investigated the impact of brain ischemia on the biosynthesis of a key neuropeptide-processing enzyme, carboxypeptidase E (CPE). The response to brain ischemia of animals that lacked an active CPE was also examined. Combined in situ hybridization and immunocytochemical analyses for CPE showed reciprocal changes of CPE mRNA and protein, respectively, in the same cortical cells in rat brains after focal cerebral ischemia. Western blot analysis revealed an accumulation of the precursor protein of CPE in the ischemic cortex in vivo and in ischemic cortical neurons in vitro. Detailed metabolic labeling experiments on ischemic cortical neurons showed that ischemic stress caused a blockade in the proteolytic processing of CPE. When mice lacking an active CPE protease were subjected to a sublethal episode of focal cerebral ischemia, abundant TUNEL-positive cells were seen in the ischemic cortex whereas only a few were seen in the cortex of wild-type animals. These findings suggest that ischemia has an adverse impact on the neuropeptide-processing system in the brain and that the lack of an active neuropeptide-processing enzyme exacerbates ischemic brain injury.
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Affiliation(s)
- An Zhou
- Robert S. Dow Neurobiology Laboratories, Legacy Research, Portland, Oregon, USA
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