title: Angioprotectin: an angiotensin II-like peptide causing vasodilatory effects.
abstract: The family of angiotensin peptides has been steadily growing in recent years. Most are fragments of angiotensin II (Ang II) with different affinities to the known angiotensin receptors. Here, we describe a novel endogenous Ang II-like octapeptide in plasma from healthy humans and patients with end-stage renal failure, which acts as a stronger agonist at Mas receptors than Ang 1-7. Chromatographic purification and structural analysis by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) revealed an Ang II-like octapeptide, angioprotectin, with the sequence Pro-Glu-Val-Tyr-Ile-His-Pro-Phe, which differs from Ang II in Pro¹ and Glu² instead of Asp¹ and Arg². Pro-Glu-Val-Tyr-Ile-His-Pro-Phe in angioprotectin is most likely generated enzymatically from Ang II. Angioprotectin antagonized the contractile actions of Ang II on rat aortic rings. The physiological antagonism of vasoconstrictor actions of Ang II by angioprotectin is mediated by the Mas receptor. Angioprotectin has a stronger affinity to the Mas receptor than Ang-1-7. Plasma concentrations were ~15% of plasma Ang II concentrations in healthy volunteers and up to 50% in patients with renal failure. A commercially available Ang II antibody did not discriminate between angioprotectin and Ang II; thus, angioprotectin can contribute to Ang II concentrations measured by antibody-based assays. This novel peptide is likely to be a relevant component of the human renin-angiotensin-system.
authors.affiliation: Medizinische Klinik IV, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Jankowski
authors.forename: Markus
authors.initials: M
authors.lastname: Tölle
authors.forename: Robson A S
authors.initials: RA
authors.lastname: Santos
authors.forename: Thomas
authors.initials: T
authors.lastname: Günthner
authors.forename: Eberhard
authors.initials: E
authors.lastname: Krause
authors.forename: Michael
authors.initials: M
authors.lastname: Beyermann
authors.forename: Pia
authors.initials: P
authors.lastname: Welker
authors.forename: Michael
authors.initials: M
authors.lastname: Bader
authors.forename: Sergio Veloso Brant
authors.initials: SV
authors.lastname: Pinheiro
authors.forename: Walkyria O
authors.initials: WO
authors.lastname: Sampaio
authors.forename: Roberto
authors.initials: R
authors.lastname: Lautner
authors.forename: Axel
authors.initials: A
authors.lastname: Kretschmer
authors.forename: Markus
authors.initials: M
authors.lastname: van der Giet
authors.forename: Walter
authors.initials: W
authors.lastname: Zidek
authors.forename: Joachim
authors.initials: J
authors.lastname: Jankowski
mesh_terms: D000368:Aged; D000804:Angiotensin II / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology; D000818:Animals; D001011:Aorta; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D051381:Rats; D051437:Renal Insufficiency / Q000097:blood; D014664:Vasodilation / Q000187:drug effects*
chemical_list: C562253:prolyl-glutamyl-valyl-tyrosyl-isoleucyl-histidyl-prolyl-phenylalanine; D000804:Angiotensin II