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Antón Palma B, Leff Gelman P, Medecigo Ríos M, Calva Nieves JC, Acevedo Ortuño R, Matus Ortega ME, Hernández Calderón JA, Hernández Miramontes R, Flores Zamora A, Salazar Juárez A. Generation of a novel monoclonal antibody that recognizes the alpha (α)-amidated isoform of a valine residue. BMC Neurosci 2015; 16:65. [PMID: 26463686 PMCID: PMC4603347 DOI: 10.1186/s12868-015-0206-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 10/01/2015] [Indexed: 11/10/2022] Open
Abstract
Background Alpha (α)-amidation of peptides is a mechanism required for the conversion of prohormones into functional peptide sequences that display biological activities, receptor recognition and signal transduction on target cells. Alpha (α)-amidation occurs in almost all species and amino acids identified in nature. C-terminal valine amide neuropeptides constitute the smallest group of functional peptide compounds identified in neurosecretory structures in vertebrate and invertebrate species. Methods The α-amidated isoform of valine residue (Val-CONH2) was conjugated to KLH-protein carrier and used to immunize mice. Hyperimmune animals displaying high titers of valine amide antisera were used to generate stable hybridoma-secreting mAbs. Three productive hybridoma (P15A4, P17C11, and P18C5) were tested against peptides antigens containing both the C-terminal α-amidated (–CONH2) and free α-carboxylic acid (−COO−) isovariant of the valine residue. Results P18C5 mAb displayed the highest specificity and selectivity against C-terminal valine amidated peptide antigens in different immunoassays. P18C5 mAb-immunoreactivity exhibited a wide distribution along the neuroaxis of the rat brain, particularly in brain areas that did not cross-match with the neuronal distribution of known valine amide neuropeptides (α-MSH, adrenorphin, secretin, UCN1-2). These brain regions varied in the relative amount of putative novel valine amide peptide immunoreactive material (nmol/μg protein) estimated through a fmol-sensitive solid-phase radioimmunoassay (RIA) raised for P18C5 mAb. Conclusions Our results demonstrate the versatility of a single mAb able to differentiate between two structural subdomains of a single amino acid. This mAb offers a wide spectrum of potential applications in research and medicine, whose uses may extend from a biological reagent (used to detect valine amidated peptide substances in fluids and tissues) to a detoxifying reagent (used to neutralize exogenous toxic amide peptide compounds) or as a specific immunoreagent in immunotherapy settings (used to reduce tumor growth and tumorigenesis) among many others.
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Affiliation(s)
- Benito Antón Palma
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
| | - Philippe Leff Gelman
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico. .,Department of Neuroscience, National Institute of Perinatology, Montes Urales # 800, 11000, México D.F., Mexico.
| | - Mayra Medecigo Ríos
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
| | - Juan Carlos Calva Nieves
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
| | - Rodolfo Acevedo Ortuño
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
| | - Maura Epifanía Matus Ortega
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
| | - Jorge Alberto Hernández Calderón
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
| | - Ricardo Hernández Miramontes
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
| | - Anabel Flores Zamora
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
| | - Alberto Salazar Juárez
- Molecular Neurobiology and Addictive Neurochemistry Laboratory, National Institute of Psychiatry, Calzada México-Xochimilco #101, 14370, México D.F., Mexico.
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González-Yanes C, Santos-Alvarez J, Sánchez-Margalet V. Pancreastatin, a chromogranin A-derived peptide, activates Galpha(16) and phospholipase C-beta(2) by interacting with specific receptors in rat heart membranes. Cell Signal 2001; 13:43-9. [PMID: 11257446 DOI: 10.1016/s0898-6568(00)00127-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Pancreastatin (PST) is one of the chromogranin A (CGA)-derived peptides with known biological activity. It has a general inhibitory effect on secretion in many exocrine and endocrine systems including the heart atrium. Besides, a role of PST as a counter-regulatory peptide of insulin action has been proposed in the light of its effects on glucose and lipid metabolism in the liver and adipose tissue, where receptors and signaling have been described. Galpha(q/11) pathway seems to mediate PST action. Since PST has been shown to function as a typical calcium-dependent hormone, and increased plasma levels have been found in essential hypertension correlating with catecholamines, we sought to study its possible interaction and signaling in heart membranes. Here, we are characterizing specific PST binding sites and signaling in rat heart membranes. We have found that PST receptor has a K(d) of 0.5 nM and a B(max) of 34 fmol/mg of protein. The PST binding is inhibited by guanine nucleotides, suggesting the functional coupling of the receptor with GTP binding proteins (G proteins). Moreover, PST dose-dependently increases GTP binding to rat heart membranes. Finally, we have studied PST signaling-effector system by measuring phospholipase C (PLC) activity using blocking antibodies against different G proteins and PLC isoforms. We have found that PST stimulates PLCbeta(2)>PLCbeta(1)>PLCbeta(3) by activating Galpha(16) in rat heart membranes. These data suggest that PST may modulate the cardiac function.
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Affiliation(s)
- C González-Yanes
- Department of Medical Biochemistry and Molecular Biology, School of Medicine, University Hospital Virgen Macarena, Av. Sanchez Pizjuan 4, 41009, Seville, Spain
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Sánchez-Margalet V, Lucas M, Goberna R. Pancreastatin action in the liver: dual coupling to different G proteins. Cell Signal 1996; 8:9-12. [PMID: 8777144 DOI: 10.1016/0898-6568(95)02014-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Pancreastatin is a 49 amino acid peptide first isolated, purified and characterized from porcine pancreas. Its biological activity in different tissues can be assigned to the C-terminal part of the molecule. Pancreastatin has a prohormonal precursor, chromogranin A, which is a glycoprotein present in neuroendocrine cells, including the endocrine pancreas. We have been interested in pancreastatin action in the liver. We found that pancreastatin has a glycogenolytic effect in the hepatocyte both in vivo and in vitro. We then studied and characterized the specific pancreastatin receptor in the rat liver plasma membrane, as well as the specific signal transduction. This receptor appears to be coupled to two different G proteins. A pertussis toxin-insensitive G proteins leads to the activation of phospholipase C, and therefore mediates the glycogenolytic effect in the liver by increasing cytoplasmic free calcium and stimulating protein kinase C. The role of cyclic GMP in the action of pancreastatin is not known yet, although it seems to regulate negatively the activation of phospholipase C. The precise mechanism by which pancreastatin stimulates guanylate cyclase activity remains to be studied.
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Affiliation(s)
- V Sánchez-Margalet
- Departamento De Bioquímica Médica y Biología Molecular, Facultad De Medicina, Universidad De Sevilla, Hospital Universitario Virgen Macarena, Spain
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