title: Structure-activity relationships of alpha-human atrial natriuretic peptide (alpha-hANP) analogs: role of charged groups in alpha-hANP.
abstract: To determine whether the addition of a methylene unit in the side chain of the Asp or Arg residue in alpha-human atrial natriuretic peptide (alpha-hANP) influences its biological activity, analogs of alpha-hANP, [Glu13]-alpha-hANP (7-28) (1), [Aad13]-alpha-hANP (7-28) (2), and [Harn]-alpha-hANP(7-28) (where n is any possible combination of 11, 14 and 27) (3-9), where the original Asp or Arg residue was replaced by a homo-amino acid, were synthesized by the solid-phase synthesis method. All the analogs were evaluated for their receptor binding, cyclic guanosine monophosphate (cGMP) accumulation activity in rat vascular smooth muscle cells (VSMC), and for vasorelaxant activity employing rat aorta. 1 and 2 were 0.9 and 0.03 times as potent as alpha-hANP (7-28), respectively, in binding. Har-containing analogs (3-9) were as potent as alpha-hANP (7-28) in binding. Among the Har-containing analogs, [Har11,14]-alpha-hANP (7-28) (6) and [Har11,27]-alpha-hANP (7-28) (7) were remarkably vasorelaxant active, being 4.2 and 5.3 times potent than alpha-hANP (7-28), respectively, in spite of relatively lower cGMP accumulation activity in the case of 7. The roles of the chargeable amino acid residues in biological activity are discussed.
authors.affiliation: Suntory Institute for Biomedical Research, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Minamitake
authors.forename: Y
authors.initials: Y
authors.lastname: Kitajima
authors.forename: M
authors.initials: M
authors.lastname: Furuya
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000737:chemistry / Q000494:pharmacology*; D006152:Cyclic GMP / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship
chemical_list: D010446:Peptide Fragments; D009320:Atrial Natriuretic Factor; D006152:Cyclic GMP