BR-bombesin: a novel bombesin-related peptide from the skin secretion of the Chaco tree frog (Boana raniceps) with physiological gastric effects

Bombesin mediates several biological activities in the gastrointestinal (GI) tract and central nervous system in mammals, including smooth muscle contraction, secretion of GI hormones and regulation of homeostatic mechanisms. Here, we report a novel bombesin-like peptide isolated from Boana raniceps. Its amino acid sequence, GGNQWAIGHFM-NH2, was identified and structurally confirmed by HPLC, MS/MS and 454-pyrosequencing; the peptide was named BR-bombesin. The effect of BR-bombesin on smooth muscle contraction was assessed in ileum and esophagus, and its anti-secretory activity was investigated in the stomach. BR-bombesin exerted significant contractile activity with a concentration–response curve similar to that of commercially available bombesin in ileum strips of Wistar rats. In esophageal strips, BR-bombesin acted as an agonist, as many other bombesin-related peptides act, although with different behavior compared to the muscarinic agonist carbachol. Moreover, BR-bombesin inhibited stomach secretion by approximately 50% compared to the untreated control group. This novel peptide has 80% and 70% similarity with the 10-residue C-terminal domain of human neuromedin B (NMB) and human gastrin releasing peptide (GRP10), respectively. Molecular docking analysis revealed that the GRP receptor had a binding energy equal to − 7.3 kcal.mol−1 and − 8.5 kcal.mol−1 when interacting with bombesin and BR-bombesin, respectively. Taken together, our data open an avenue to investigate BR-bombesin in disorders that involve gastrointestinal tract motility and acid gastric secretion.Fil: de Sousa, Nayara Alves. Universidade Estadual do Ceará; BrasilFil: Marani, Mariela Mirta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Fernandes Lopes, André Luís. Universidade Federal do Delta do Parnaíba; BrasilFil: Morais Silva, Emanuelle. Universidade Federal do Delta do Parnaíba; Brasil. Universidade Federal do Piaui; BrasilFil: Alves Barbosa, Eder. Universidade do Brasília; BrasilFil: Gomes Vasconcelos, Andreanne. Universidade do Brasília; BrasilFil: Kuzniewski, Felipe T. B.. Universidade do Brasília; BrasilFil: Sousa Lustosa, Suellen. Universidade Federal do Delta do Parnaíba; BrasilFil: Pereira Gomes, Karina. Universidade Federal de Goiás; BrasilFil: Basile Colugnati, Diego. Universidade Federal de Goiás; BrasilFil: Rocha, Jefferson A.. Universidade Federal do Maranhão; BrasilFil: Santos, Lucianna Helene. Universidade Federal de Minas Gerais; BrasilFil: Benquerer, Marcelo P.. Embrapa Recursos Genéticos e Biotecnologia; BrasilFil: Quelemes, Patrick. Universidade Federal do Delta do Parnaíba; Brasil. Universidade Federal do Piaui; BrasilFil: Véras, Leiz. Universidade Federal do Delta do Parnaíba; BrasilFil: Moreira, Daniela. Universidade do Brasília; BrasilFil: Lima Gadelha, Kalinne Kelly. Universidade Estadual do Ceará; BrasilFil: Caldas Magalhães, Pedro Jorge. Universidade Estadual do Ceará; BrasilFil: Plácido, Alexandra. Universidad de Porto; PortugalFil: Eaton, Peter. Universidad de Porto; PortugalFil: Nicolau, Lucas. Universidade Federal do Delta do Parnaíba; BrasilFil: Medeiros, Jand Venes R.. Universidade Federal do Delta do Parnaíba; BrasilFil: Leite, José R. S. A.. Universidade do Brasília; Brasi