PARTIAL CHARACTERIZATION OF LETHAL AND NEUROACTIVE COMPONENTS OF THE BROWN RECLUSE SPIDER (LOXOSCELES-RECLUSA) VENOM

L. D. Foil, J. L. Frazier and B. R. Norment. Partial characterization of lethal and neuroactive components of the brown recluse spider (Loxosceles reclusa) venom. Toxicon 17, 347-354, 1979.-Loxosceles reclusa venom was separated by Sephadex G-50 gel filtration into three 280 nm absorbing peaks, two of which contained components lethal to insects. The heavy molecular weight (mol. wt) protein found in peak 1 caused knockdown and mortality in Musca domestica 20-24 hr after injection. The low mol. wt (less than 10,000) polypeptide in peak 2 was heat stable at 90°C and caused knockdown within 30 min and mortality within four hr after injection. Both whole venom and peak 2 contained components which caused a dramatic increase in the amplitude and frequency of the endogenous activity of the ventral nerve cord of Periplaneta americana. The neuroactive factor stimulated this activity to 680-fold and with 5 min produced a block which was reversible by saline irrigation. Gel filtration elutions of the low mol. wt lethal factor and the neuroactive factor overlapped but did not coincide. © 1979.