Physiological and biochemical analysis of L. tredecimguttatusvenom collected by electrical stimulation

ABSTRACT

The L. tredecimguttatus venom was collected by electrical stimulation and systematicallyanalyzed. Gel electrophoresis and RP-HPLC showed that the venomconsisted primarily of proteins with molecular weights above 10 kDa, most of whichwere high-molecular-mass acidic proteins, with fewer proteins and peptides below 10kDa. The most abundant proteins in the venom were concentrated at around 100kDa, which included latrotoxins- the principal toxic components of the venom.Injection of the venom in mice and cockroaches P. americana gave rise to obviouspoisoned symptoms, with LD50 values of 0.16 mg/kg and 1.87 ìg/g , respectively.Electrophysiological experiments showed that the venom could block the neuromusculartransmission in isolated mouse phrenic nerve-hemidiaphragm and rat vasdeferens preparations. The low-molecular-weight fraction (<10 kDa) of the venomhad no effect on the transmission. Enzymatic analysis indicated that the venom possessactivities of several kinds of hydrolases including hyaluronidase and proteases.These results demonstrated that L. tredecimguttatus venom was basically a large-protein-constituted venom and is one of the most poisonous spider venoms known inthe world. The mammalian toxicity of the venom was based on its larger proteinsrather than on smaller proteins and peptides, and its hydrolase activities might beinvolved in the latrodectism. The use of electrical stimulation method to collect thevenom has the advantages of avoiding contamination and repeated use of the valuableL. tredecimguttatus venom resources (AU)

RESUMEN

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