2543 Stromatoxin Stromatoxin is a peptide spider toxin produced by the Featherleg baboon tarantula (Stromatopelma calceatum). This spider lives high in the canopy tops of tropical forests in West Africa. Stromatoxin blocks certain delayed-rectifier and A-type voltage-gated potassium channels. (L1029) Stromatoxin is a peptide consisting of 34 amino acids that belongs to the structural family of ‘inhibitor cystine knot’ spider peptides. 1262235-00-6 3798.295000000001 Clear solution. >10 mg/mL Injection (sting/bite) (L1812) Stromatoxin blocks the delayed-rectifier type potassium channels Kv2.1, Kv2.2, Kv2.1/9.3 and the A-type potassium channel Kv4.2, with affinity (IC50) of 12.7 nM, 21.4 nM, 7.2 nM and 1.2 nM, respectively. No activity on Kv4.1 and Kv4.3 has been observed. The effect of stromatoxin on potassium channels is voltage-dependent, maximal inhibition is reached between –30 and 0 mV, while inhibition is only partial at values more positive than +10 mV. The toxin therefore acts as a gating modifier, shifting the activation of the channel to more depolarized potentials. Although the channel can still be activated, a much larger depolarization is needed. (A15116) Free toxin may be removed by opsonization via the reticuloendothelial system (primarily the liver and kidneys) or it may be degraded through cellular internalization via the lysosomes. Lysosomes are membrane-enclosed organelles that contain an array of digestive enzymes, including several proteases. No indication of carcinogenicity to humans (not listed by IARC). Stromatoxin is a peptide toxin produced by the Featherleg baboon tarantula (Stromatopelma calceatum). (L1029) Bites from the Featherleg baboon tarantula are very painful. There is only one recorded death from a featherleg baboon tarantula bite (a soldier in South Africa). Throbbing pain at site of bite. Redness, swelling, burning sensation, some joint pain near bite. Some cramping may develop in joints. Most symptoms disappear after 1-2 days. Minor bites and stings can be treated by: 1) washing the affected area with soap and water; 2) placing a cold compress (a flannel or cloth cooled with cold water) over the affected area to reduce swelling and 3) not scratching the area as it can become infected. If the symptoms of a systemic reaction (SR) appear, it could lead to anaphylactic shock. Anaphylaxis may need to be treated with an adrenaline injection, antihistamines, oxygen or an intravenous drip directly into a vein. 2009-07-03T22:19:01Z 2014-12-24T20:25:37Z http://en.wikipedia.org/wiki/Stromatoxin P60991 true Exogenous Liquid BSEQ0008432