title: Structural and functional characterization of a mutant of Pseudocerastes persicus natriuretic peptide.
abstract: We hereby report on a mutational analysis of a novel natriuretic peptide (PNP), recently isolated by us from the Iranian snake venom. The PNP variant (mutPNP) with four substitutions (G16T, K18S, R21S, G23R) and a disulfide bonded ring shortened by 3 residues. mutPNP peptide was expressed in pET32 and purified by affinity separation on nickel resin followed by RP-HPLC chromatography. The conformation of mutPNP was characterized in solution by 1H nuclear magnetic resonance spectroscopy, where it was found that the 14-residue disulfide bonded ring, like the 17-residue ring in PNP, retains a high degree of conformational flexibility. The conformation of mutPNP bound to NPR-C receptor was predicted by homology protein structure modeling. When injected intravenously into rats, mutPNP, in contrast to PNP had no physiological effect on blood pressure or on diuresis. The loss of physiological activity is explained in terms of the modeled bound conformation and the ensemble of solution conformations obtained using the NMR constraints.
authors.affiliation: Institute of Biochemistry and Biophysics, Tehran University, P.O. Box 13145-1384, Tehran, Iran.
authors.forename: Maryam M
authors.initials: MM
authors.lastname: Elmi
authors.forename: Mehriar
authors.initials: M
authors.lastname: Amininasab
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hondo
authors.forename: Jun
authors.initials: J
authors.lastname: Kikuchi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Hossein
authors.initials: H
authors.lastname: Naderi-Manesh
authors.forename: Mohammad N
authors.initials: MN
authors.lastname: Sarbolouki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D017124:Conserved Sequence; D004220:Disulfides / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D045265:Natriuretic Peptides / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D051381:Rats; D017208:Rats, Wistar; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014757:Viper Venoms / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000494:pharmacology; D017819:Viperidae
chemical_list: D004220:Disulfides; D045265:Natriuretic Peptides; D014757:Viper Venoms