has role has role is conjugate base of bradykinin(2+) oligopeptide bradykinin CHEBI:3165 RPPGFSPFR chebi_ontology BK A linear nonapeptide messenger belonging to the kinin group of proteins, with amino acid sequence RPPGFSPFR. Enzymatically produced from kallidin in the blood, it is a powerful vasodilator that causes smooth muscle contraction, and may mediate inflammation. Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg L-Arg-L-Pro-L-Pro-Gly-L-Phe-L-Ser-L-Pro-L-Phe-L-Arg L-bradykinin vasodilator agent human blood serum metabolite