title: Characterization of the venom from the Brazilian Brown Spider Loxosceles similis Moenkhaus, 1898 (Araneae, Sicariidae).
abstract: Accidents caused by brown spiders (Loxosceles genus) are frequent in Brazil and are associated with dermonecrotic lesions and, eventually, systemic reactions that may be lethal. The major species implicated with human envenoming have been: L. intermedia, L. gaucho and L. laeta. In this study we characterized the venom from Loxosceles similis, a species of spider normally found inside caves. L. similis venom was characterized by two-dimensional gel electrophoresis and enzymatic activity (dermonecrosis and haemolysis). The lethal dose to mice and the capacity of commercial anti-serum to neutralize this venom were also analysed. The cross-reactivity with anti-venoms against L. intermedia, L. laeta and L. gaucho were studied. Our results showed that this venom was able to induce severe dermonecrotic lesions and showed the presence of the bacteria Clostridium septicum in association with the fangs. In addition, we have cloned the DNA coding for a dermonecrotic protein (LsD1), using the genomic DNA of L. similis. The deduced amino acid sequence showed a toxin of approximately 31.2 kDa with an estimated pI of 7.37 and sequence similar to LiD1, a protein from the dermonecrotic family of Loxosceles intermedia spider venom, a synanthropic species of medical importance.
authors.affiliation: Departamento de Biologia Geral, Instituto de Ciências Biológicas, ICB, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG, CEP 31270901, Brazil.
authors.forename: F G
authors.initials: FG
authors.lastname: Silvestre
authors.forename: C S
authors.initials: CS
authors.lastname: de Castro
authors.forename: J F
authors.initials: JF
authors.lastname: de Moura
authors.forename: M S
authors.initials: MS
authors.lastname: Giusta
authors.forename: M
authors.initials: M
authors.lastname: De Maria
authors.forename: E S S
authors.initials: ES
authors.lastname: Alvares
authors.forename: F C F
authors.initials: FC
authors.lastname: Lobato
authors.forename: R A
authors.initials: RA
authors.lastname: Assis
authors.forename: L A
authors.initials: LA
authors.lastname: Gonçalves
authors.forename: I C
authors.initials: IC
authors.lastname: Gubert
authors.forename: C
authors.initials: C
authors.lastname: Chávez-Olórtegui
authors.forename: E
authors.initials: E
authors.lastname: Kalapothakis
mesh_terms: D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D001938:Brazil; D003013:Clostridium / Q000302:isolation & purification; D003429:Cross Reactions / Q000276:immunology; D017931:DNA Primers; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006461:Hemolysis / Q000187:drug effects; D007106:Immune Sera / Q000494:pharmacology; D007928:Lethal Dose 50; D051379:Mice; D008969:Molecular Sequence Data; D009336:Necrosis; D010727:Phosphoric Diester Hydrolases / Q000235:genetics / Q000302:isolation & purification* / Q000633:toxicity*; D017422:Sequence Analysis, DNA; D012867:Skin / Q000473:pathology*; D013045:Species Specificity; D013111:Spider Venoms / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification* / Q000633:toxicity*; D013112:Spiders / Q000737:chemistry* / Q000382:microbiology
chemical_list: D017931:DNA Primers; D007106:Immune Sera; D013111:Spider Venoms; C055161:loxosceles venom; D010727:Phosphoric Diester Hydrolases