title: Bowman-Birk protease inhibitor from Vigna unguiculata seeds enhances the action of bradykinin-related peptides.
abstract: The hydrolysis of bradykinin (Bk) by different classes of proteases in plasma and tissues leads to a decrease in its half-life. Here, Bk actions on smooth muscle and in vivo cardiovascular assays in association with a protease inhibitor, Black eyed-pea trypsin and chymotrypsin inhibitor (BTCI) and also under the effect of trypsin and chymotrypsin were evaluated. Two synthetic Bk-related peptides, Bk1 and Bk2, were used to investigate the importance of additional C-terminal amino acid residues on serine protease activity. BTCI forms complexes with Bk and analogues at pH 5.0, 7.4 and 9.0, presenting binding constants ranging from 103 to 104 M-1. Formation of BTCI-Bk complexes is probably driven by hydrophobic forces, coupled with slight conformational changes in BTCI. In vitro assays using guinea pig (Cavia porcellus) ileum showed that Bk retains the ability to induce smooth muscle contraction in the presence of BTCI. Moreover, no alteration in the inhibitory activity of BTCI in complex with Bk and analogous was observed. When the BTCI and BTCI-Bk complexes were tested in vivo, a decrease of vascular resistance and consequent hypotension and potentiating renal and aortic vasodilatation induced by Bk and Bk2 infusions was observed. These results indicate that BTCI-Bk complexes may be a reliable strategy to act as a carrier and protective approach for Bk-related peptides against plasma serine proteases cleavage, leading to an increase in their half-life. These findings also indicate that BTCI could remain stable in some tissues to inhibit chymotrypsin or trypsin-like enzymes that cleave and inactivate bradykinin in situ.
authors.affiliation: Laboratório de Biofísica, Instituto de Biologia, Departamento de Biologia Celular, Universidade de Brasília-UnB, Quadra 604, Asa Norte, Bloco J 1° andar, Brasília, DF 70910-900, Brazil. pharmalice@gmail.com.
authors.forename: Alice
authors.initials: A
authors.lastname: da Cunha Morales Álvares
authors.affiliation: Laboratório de Toxinologia, Departamento de Ciências Fisiológicas, Universidade de Brasília-UnB, Quadra 604, Asa Norte, Bloco J Térreo, Brasília, DF 70910-900, Brazil. efschwa@unb.br.
authors.forename: Elisabeth Ferroni
authors.initials: EF
authors.lastname: Schwartz
authors.affiliation: Center of Neuroscience and Cardiovascular Physiology, Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Estrada do Campus, Goiânia, GO 74690-900, Brazil. oda_ufg@posgrad.ufg.br.
authors.forename: Nathalia Oda
authors.initials: NO
authors.lastname: Amaral
authors.affiliation: Center of Neuroscience and Cardiovascular Physiology, Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Estrada do Campus, Goiânia, GO 74690-900, Brazil. neidiane@posgrad.ufg.br.
authors.forename: Neidiane Rosa
authors.initials: NR
authors.lastname: Trindade
authors.affiliation: Center of Neuroscience and Cardiovascular Physiology, Department of Physiological Sciences, Biological Sciences Institute, Federal University of Goiás, Estrada do Campus, Goiânia, GO 74690-900, Brazil. pedrino@ufg.br.
authors.forename: Gustavo Rodrigues
authors.initials: GR
authors.lastname: Pedrino
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, Laboratório de Espectrometria de Massa, PBI, Parque Estação Biológica, Final W5 Norte, Asa Norte, Brasília, DF 70770-917, Brazil. luciano.paulino@embrapa.br.
authors.forename: Luciano Paulino
authors.initials: LP
authors.lastname: Silva
authors.affiliation: Laboratório de Biofísica, Instituto de Biologia, Departamento de Biologia Celular, Universidade de Brasília-UnB, Quadra 604, Asa Norte, Bloco J 1° andar, Brasília, DF 70910-900, Brazil. nina@unb.br.
authors.forename: Sonia Maria
authors.initials: SM
authors.lastname: de Freitas
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000378:metabolism*; D002319:Cardiovascular System / Q000187:drug effects / Q000378:metabolism; D002918:Chymotrypsin / Q000378:metabolism; D007887:Fabaceae / Q000737:chemistry*; D006168:Guinea Pigs; D006207:Half-Life; D057927:Hydrophobic and Hydrophilic Interactions; D007082:Ileum / Q000187:drug effects / Q000378:metabolism; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry*; D057057:Serine Proteases / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects
chemical_list: D010455:Peptides; D010940:Plant Proteins; D011480:Protease Inhibitors; C042736:trypsin, chymotrypsin inhibitor, black-eyed pea; D057057:Serine Proteases; D002918:Chymotrypsin; D001920:Bradykinin