title: AGH is a new hemoglobin alpha-chain fragment with antinociceptive activity.
abstract: Limited proteolysis of certain proteins leads to the release of endogenous bioactive peptides. Hemoglobin-derived peptides such as hemorphins and hemopressins are examples of intracellular protein-derived peptides that have antinociceptive effects by modulating G-protein coupled receptors activities. In the present study, a previously characterized substrate capture assay that uses a catalytically inactive form of the thimet oligopeptidase was combined with isotopic labeling and mass spectrometry in order to identify new bioactive peptides. Indeed, we have identified the peptide AGHLDDLPGALSAL (AGH), a fragment of the hemoglobin alpha-chain, which specifically bind to the inactive thimet oligopeptidase in the substrate capture assay. Previous peptidomics studies have identified the AGH as well as many other natural peptides derived from hemoglobin alpha-chain containing this sequence, further suggesting that AGH is a natural endogenous peptide. Pharmacological assays suggest that AGH inhibits peripheral inflammatory hyperalgesic responses through indirect activation of mu opioid receptors, without having a central nervous system activity. Therefore, we have successfully used the substrate capture assay to identify a new endogenous bioactive peptide derived from hemoglobin alpha-chain.
authors.affiliation: Department of Cell Biology and Development, Biomedical Sciences Institute (ICB), University of São Paulo (USP), Av. Prof. Lineu Prestes, 1524, S435, São Paulo, SP 05508-00, Brazil. Electronic address: natmazini@gmail.com.
authors.forename: Natalia M
authors.initials: NM
authors.lastname: Ribeiro
authors.forename: Elaine F
authors.initials: EF
authors.lastname: Toniolo
authors.forename: Leandro M
authors.initials: LM
authors.lastname: Castro
authors.forename: Lilian C
authors.initials: LC
authors.lastname: Russo
authors.forename: Vanessa
authors.initials: V
authors.lastname: Rioli
authors.forename: Emer S
authors.initials: ES
authors.lastname: Ferro
authors.forename: Camila S
authors.initials: CS
authors.lastname: Dale
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000700:Analgesics / Q000008:administration & dosage* / Q000737:chemistry; D000818:Animals; D002351:Carrageenan / Q000633:toxicity; D006221:Halothane / Q000008:administration & dosage; D006454:Hemoglobins / Q000008:administration & dosage* / Q000737:chemistry; D006801:Humans; D006930:Hyperalgesia / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D007249:Inflammation / Q000139:chemically induced / Q000188:drug therapy / Q000378:metabolism; D008666:Metalloendopeptidases / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D010146:Pain / Q000139:chemically induced / Q000188:drug therapy*; D010455:Peptides / Q000008:administration & dosage* / Q000737:chemistry; D051381:Rats; D017450:Receptors, Opioid, mu; D013379:Substrate Specificity
chemical_list: D000700:Analgesics; D006454:Hemoglobins; D010455:Peptides; D017450:Receptors, Opioid, mu; D002351:Carrageenan; D008666:Metalloendopeptidases; C022510:thimet oligopeptidase; D006221:Halothane
keywords: 35S labeled radioligand guanosine 5′-O-(γ-thio)triphosphate; 4-trimethylammoniumbutyryl; 7-methoxycoumarin-4-acetyl-Pro-Leu-Gly-Pro-dLys-2,4-dinitrophenyl; AGH; AGHLDDLPGALSAL; D0-TMAB; D3-TMAB; D6-TMAB; D9-TMAB; EP24.15; Hemoglobin-derived peptides; Hemopressin; Hyperalgesia; Inflammation; Opioid; QFS; SCA; TMAB; TMAB containing nine atoms of deuterium; TMAB containing no deuterium; TMAB containing six atoms of deuterium; TMAB containing three atoms of deuterium; [(35)S]GTPγS; substrate capture assay; thimet oligopeptidase (EC 3.4.24.15)