title: A novel bradykinin-like peptide from skin secretions of the frog, Rana nigrovittata.
abstract: A bradykinin-like peptide has been isolated from the skin secretions of the frog Rana nigrovittata. This peptide was named ranakinin-N. Its primary structure, RAEAVPPGFTPFR, was determined by Edman degradation and mass spectrometry. It is structurally related to bradykinin-like peptides identified from skin secretions of other amphibians. Ranakinin-N is composed of 13 amino acid residues and is related to the bradykinin identified from the skin secretions of Odorrana schmackeri, which is composed of 9 amino acid residues. Ranakinin-N was found to exert concentration-dependent contractile effects on isolated guinea pig ileum. cDNA sequence encoding the precursor of ranakinin-N was isolated from a skin cDNA library of R. nigrovittata. The amino acid sequences deduced from the cDNA sequences match well with the results from Edman degradation. Analysis of different amphibian bradykinin cDNA structures revealed that the deficiency of a 15-nucleotide fragment (agaatgatcagacgc in the cDNA encoding bradykinin from O. schmackeri) in the peptide-coding region resulted in the absence of a dibasic site for trypsin-like proteinases and an unusual -AEVA- insertion in the N-terminal part of ranakinin-N. The -AEAV- insertion resulted in neutral net charge at the N-terminus of ranakinin-N. Ranakinin-N is the first reported bradykinin-like peptide with a neutral net charge at the N-terminus.
authors.affiliation: Key Laboratory of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, Life Sciences College of Nanjing Agricultural University, Nanjing, Jiangsu, China.
authors.forename: Xiuhong
authors.initials: X
authors.lastname: Liu
authors.forename: Dewen
authors.initials: D
authors.lastname: You
authors.forename: Lihua
authors.initials: L
authors.lastname: Chen
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.forename: Keyun
authors.initials: K
authors.lastname: Zhang
authors.forename: Ren
authors.initials: R
authors.lastname: Lai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001920:Bradykinin / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D015723:Gene Library; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009119:Muscle Contraction / Q000187:drug effects; D009842:Oligopeptides / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D011898:Ranidae / Q000235:genetics / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012867:Skin / Q000378:metabolism
chemical_list: D017931:DNA Primers; D009842:Oligopeptides; D010455:Peptides; C071642:ranakinin; D001920:Bradykinin