Venom Components of Brachypelma vagans, a Mexican Tarantula.
Clement, Herlinda; Alagón, Alejandro; Possani, Lourival and Odell, George V.
Instituto de Biotecnologia, UNAM. Cuernavaca, Mor. 62210. México
Pooled venom samples of the Mexican tarantula, Brachypelma vagans, are clear, colorless, with a pH of 5.5 to 5.7, a solid content of 16%, and a volatile (water) content of 84%. Gel filtration of venom shows several exclusion proteins (which include hyaluronidase), peptide toxins, acylpolyamines, adenosine triphosphate, and citrate. Hyaluronidase is a "spreading factor"; the peptide toxins are lethal to insects, reptiles, and mice; the acylpolyamines are paralytic to insects; and the role of the acidic components (ATP and citrate) in venom action is not known at this time. ATP has been shown to be synergistic with the peptide toxins, and extracellular ATP is toxic to some cell types.
Citrate is well established as an anticoagulant and functions by chelation of divalent metal ions. Citrate has been shown to inhibit zinc-dependent venom proteases and calcium-dependent phospholipases A2. Citrate is also a buffer and counter ion for basic venom components such as peptides and acylpolyamines. Sephadex G-50 does not resolve the acylpolyamines from the nucleotide or citrate components. Some minor proteins are seen by PAGE between 45 and 10 kDa. Purification and sequence is planned for toxic peptides.
Publication Dates
-
Publication in this collection
08 Oct 2002 -
Date of issue
Dec 2001
