title: Structural divergence of cysteine-rich secretory proteins in snake venoms.
abstract: Cysteine-rich secretory proteins (CRISPs) are expressed in spermatocytes and granules of neutrophils in mammals, and are associated with sperm maturation and host defense. Related proteins have recently been recovered in snake venoms, and some of the snake venom-derived CRISPs exhibit ion channel blocking activity. Here we isolated and identified two novel CRISPs (kaouthin-1 and kaouthin-2) from the venom of Naja kaouthia (Elapidae), and cloned the encoding cDNAs. Kaouthin-1 and kaouthin-2 were classified into two broad sister groups of Elapidae, the Asian species and the marine/Australian species, respectively. Sequence comparisons reveal that the high-frequency variable regions among snake venom CRISPs define a continuous line on the molecular surface of the N-terminal pathogenesis-related protein-1 (PR-1) domain and the C-terminal cysteine-rich domain (CRD). Snake venom proteins generally display efficient molecular diversity around functionally key regions, suggesting that the PR-1 domain of CRISPs is important for the recognition of target molecules.
authors.affiliation: Department of Biochemistry, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Matsunaga
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Fumiko
authors.initials: F
authors.lastname: Hyodo
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nozaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Morita
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004546:Elapid Venoms / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D006023:Glycoproteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D013045:Species Specificity; D055672:Static Electricity
chemical_list: D018076:DNA, Complementary; D004546:Elapid Venoms; D006023:Glycoproteins; C521753:Naja kaouthia venom