title: Spider toxins comprising disulfide-rich and linear amphipathic domains: a new class of molecules identified in the lynx spider Oxyopes takobius.
abstract: In addition to the conventional neurotoxins and cytotoxins, venom of the lynx spider Oxyopes takobius was found to contain two-domain modular toxins named spiderines: OtTx1a, 1b, 2a and 2b. These toxins show both insecticidal activity (a median lethal dose against flesh fly larvae of 75 μg·g(-1)) and potent antimicrobial effects (minimal inhibitory concentrations in the range 0.1-10 μm). Full sequences of the purified spiderines were established by a combination of Edman degradation, mass spectrometry and cDNA cloning. They are relatively large molecules (~ 110 residues, 12.0-12.5 kDa) and consist of two distinct modules separated by a short linker. The N-terminal part (~ 40 residues) contains no cysteine residues, is highly cationic, forms amphipathic α-helical structures in a membrane-mimicking environment, and shows potent cytolytic effects on cells of various origins. The C-terminal part (~ 60 residues) is disulfide-rich (five S-S bonds), and contains the inhibitor cystine knot (ICK/knottin) signature. The N-terminal part of spiderines is very similar to linear cytotoxic peptides found in various organisms, whereas the C-terminal part corresponds to the usual spider neurotoxins. We synthesized the modules of OtTx1a and compared their activity to that of full-length mature toxin produced recombinantly, highlighting the importance of the N-terminal part, which retained full-length toxin activity in both insecticidal and antimicrobial assays. The unique structure of spiderines completes the range of two-domain spider toxins.
authors.affiliation: M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Vassilevski
authors.forename: Maria Y
authors.initials: MY
authors.lastname: Sachkova
authors.forename: Anastasija A
authors.initials: AA
authors.lastname: Ignatova
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Kozlov
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Feofanov
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Grishin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001483:Base Sequence; D002470:Cell Survival / Q000187:drug effects; D002942:Circular Dichroism; D004220:Disulfides / Q000737:chemistry* / Q000378:metabolism; D006367:HeLa Cells; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D047468:Immunoprecipitation; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D058493:Sarcophagidae / Q000187:drug effects; D017386:Sequence Homology, Amino Acid; D013111:Spider Venoms / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013112:Spiders / Q000502:physiology*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000890:Anti-Infective Agents; D004220:Disulfides; D010446:Peptide Fragments; D013111:Spider Venoms
keywords: antimicrobial peptide; cytotoxin; inhibitor cystine knot; neurotoxin; spider venom