title: Cloning and sequence analysis of an Ophiophagus hannah cDNA encoding a precursor of two natriuretic peptide domains.
abstract: The king cobra (Ophiophagus hannah) is the largest venomous snake. Despite the components are mainly neurotoxins, the venom contains several proteins affecting blood system. Natriuretic peptide (NP), one of the important components of snake venoms, could cause local vasodilatation and a promoted capillary permeability facilitating a rapid diffusion of other toxins into the prey tissues. Due to the low abundance, it is hard to purify the snake venom NPs. The cDNA cloning of the NPs become a useful approach. In this study, a 957 bp natriuretic peptide-encoding cDNA clone was isolated from an O. hannah venom gland cDNA library. The open-reading frame of the cDNA encodes a 210-amino acid residues precursor protein named Oh-NP. Oh-NP has a typical signal peptide sequence of 26 amino acid residues. Surprisingly, Oh-NP has two typical NP domains which consist of the typical sequence of 17-residue loop of CFGXXDRIGC, so it is an unusual NP precursor. These two NP domains share high amino acid sequence identity. In addition, there are two homologous peptides of unknown function within the Oh-NP precursor. To our knowledge, Oh-NP is the first protein precursor containing two NP domains. It might belong to another subclass of snake venom NPs.
authors.affiliation: Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Yunnan, Kunming 650223, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Lei
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guoyu
authors.initials: G
authors.lastname: Yu
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
authors.forename: Yingying
authors.initials: Y
authors.lastname: He
authors.forename: Wenhui
authors.initials: W
authors.lastname: Lee
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D016000:Cluster Analysis; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D004546:Elapid Venoms / Q000235:genetics*; D017815:Elapidae / Q000235:genetics*; D015723:Gene Library; D008969:Molecular Sequence Data; D045265:Natriuretic Peptides / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D017434:Protein Structure, Tertiary / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D004546:Elapid Venoms; D045265:Natriuretic Peptides