title: Skin bradykinin-related peptides (BRPs) and their biosynthetic precursors (kininogens): comparisons between various taxa of Chinese and North American ranid frogs.
abstract: Bradykinins and related peptides (BRPs) occur in the defensive skin secretions of many amphibians. Here we report the structures of BRPs and their corresponding biosynthetic precursor cDNAs from the Chinese brown frog, Rana chensinensis, and the North American leopard frog, Lithobates pipiens. R. chensinensis skin contained four transcripts each encoding a different kininogen whose organizations and spectrum of encoded BRPs were similar to those reported for the pickerel frog, Lithobates palustris. In contrast, from L. pipiens, a single skin kininogen was cloned whose structural organization and spectrum of mature BRPs were similar to those reported for the Chinese piebald odorous frog, Huia schmackeri. These data also implied that the endogenous precursor processing proteases in each species pair have identical site-directed specificities, which in part may be dictated by the primary structures of encoded BRPs. Thus the spectra of skin BRPs and the organization of their biosynthetic precursors are not consistent with recent taxonomy. The natural selective pressures that mould the primary structures of amphibian skin secretion peptides are thought to be related to the spectrum of predators encountered within their habitats. Thus similarities and differences in skin bradykinins may be reflective of predator spectra rather than indicative of species relatedness.
authors.affiliation: Molecular Therapeutics Research, School of Pharmacy, Queen's University, Belfast, Northern Ireland, UK.
authors.forename: YeeTing
authors.initials: Y
authors.lastname: Sin
authors.forename: Mei
authors.initials: M
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Tianbao
authors.initials: T
authors.lastname: Chen
authors.forename: Brian
authors.initials: B
authors.lastname: Walker
authors.forename: Chris
authors.initials: C
authors.lastname: Shaw
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001001:Anura / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001920:Bradykinin / Q000737:chemistry*; D002681:China; D007704:Kininogens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009656:North America; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D012867:Skin / Q000378:metabolism*; D013045:Species Specificity; D053719:Tandem Mass Spectrometry
chemical_list: D007704:Kininogens; D010455:Peptides; D001920:Bradykinin