Psalmopoeus cambridgei is a large, lanky and fast tarantula
species found in Trinidad. It is an arboreal species that can make
extensive sheet-like webs of a very filmy silk extending from retreats in
crevices on cliffs and road cuts, amongst exposed roots and in abandoned
buildings.
The toxicity of the venom towards humans and other mammals is not known.
This spider can bite when threatened bites may cause severe pain and
inflammation, apparently due to capsaicin (chili pepper) receptor agonists
in the venom (Siemens et al 2006). |
| The venom is best known for Psalmotoxin 1
(PcTx1), the first known selective
blocker of a proton-gated ion channel discovered by researchers in Lazdunski's
group in France. This toxin is of special interest neuroprotectant
activities and potentials in the diagnosis and treatment of aggressive
gliomas. Another French group
identified novel antimalarial peptides, Psalmopeotoxin I (PcFK1) and
Psalmopeotoxin II (PcFK2), whose targets are unknown. They do not appear to be
conventional, pore forming antimicrobials commonly found in arthropods (Choi,
Parent et al. 2004) . |
|
Selected References
Bubien, J. K., H. L. Ji, et al. (2004). "Cation selectivity and inhibition of
malignant glioma Na+ channels by Psalmotoxin 1." Am J Physiol Cell Physiol
287(5): C1282-91.
PubMed
Choi, S. J., R. Parent, et al. (2004). "Isolation and characterization of
Psalmopeotoxin I and II: two novel antimalarial peptides from the venom of the
tarantula Psalmopoeus cambridgei." FEBS Lett 572(1-3): 109-17.
PubMed
Chu, X. P., J. Miesch, et al. (2002). "Proton-gated channels in PC12 cells." J
Neurophysiol 87(5): 2555-61.
PubMed
Escoubas, P., C. Bernard, et al. (2003). "Recombinant production and solution
structure of PcTx1, the specific peptide inhibitor of ASIC1a proton-gated cation
channels." Protein Sci 12(7): 1332-43.
PubMed
Siemens, J., S.
Zhou, R. Piskorowski, T. Nikai, E. A. Lumpkin, A. I. Basbaum, D. King and
D. Julius (2006). "Spider toxins activate the capsaicin receptor to
produce inflammatory pain." Nature 444(7116): 208-212.
PubMed
Xiong, Z. G., X. M. Zhu, et al. (2004). "Neuroprotection in ischemia: blocking
calcium-permeable acid-sensing ion channels." Cell 118(6): 687-98.
PubMed |
