Helokinestatin: a new bradykinin B2 receptor antagonist decapeptide from lizard venom.
Synthetic bradykinin antagonist peptides/peptoids have been powerful tools for delineating the roles of kinins in both normal physiology and in pathological states. Here, we report the identification of a novel, naturally occurring bradykinin B2 receptor antagonist peptide, helokinestatin, isolated and structurally characterized from the venoms of helodermatid lizards-the Gila monster (Heloderma suspectum) and the Mexican beaded lizard (Heloderma horridum). The primary structure of the peptide was established by a combination of microsequencing and mass spectroscopy as Gly-Pro-Pro-Tyr-Gln-Pro-Leu-Val-Pro-Arg (Mr 1122.62). A synthetic replicate of helokinestatin was found to inhibit bradykinin-induced vasorelaxation of phenylephrine pre-constricted rat tail artery smooth muscle, mediated by the B2 receptor sub-type, in a dose-dependent manner. Natural selection, that generates functional optimization of predatory reptile venom peptides, can potentially provide new insights for drug lead design or for normal physiological or pathophysiological processes.
Kwok
Hang Fai
HF
School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, Northern Ireland, UK. h.f.kwok@qub.ac.uk <h.f.kwok@qub.ac.uk>
Chen
Tianbao
T
O'Rourke
Martin
M
Ivanyi
Craig
C
Hirst
David
D
Shaw
Chris
C
D000818:Animals; D001158:Arteries / Q000187:drug effects; D065094:Bradykinin B2 Receptor Antagonists; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008116:Lizards; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009842:Oligopeptides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D013997:Time Factors; D014688:Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
D065094:Bradykinin B2 Receptor Antagonists; D009842:Oligopeptides; D014688:Venoms; C527846:helokinestatin