23109-05-9

Inhibits eukaryotic RNA-polymerase II with high efficiency, but not eukaryotic RNA-polymerase I, or bacterial or viral RNA-polymerases. Inhibits mammalian protein synthesis.

α-amanitin, the most deleterious toxin of a. phalloides to humans, inhibits rna polymerase ii (rnapii), causing hepatic and renal failure.

The major toxic constituent of the mushroom, Amanita phalloides, inhibits eukaryotic RNA polymerase II and III, but does not inhibit RNA polymerase I or bacterial RNA polymerase. Inhibits mammalian protein synthesis.

This bicyclic octapeptide toxin (FW = 918.98 g/mol; CAS 23109-05-9; LD50 = 0.1 mg/kg i.p in albino mice) from the the death-cap fungus Amanita phalloides binds very tightly to eukaryotic RNA polymerase II (Ki ≈ 10 nM) and less tightly to eukaryotic RNA polymerase III (Ki ≈ 1 μM), blocking mRNA synthesis and inducing cytolysis of hepatocytes and kidney cells. a-Amanitin istable at room temperature, soluble in water and ethanol, and melts with decomposition at 254-255°C. Caution: Gloves should be worn, and measures should be taken to avoid inhalation. Symptoms of a toxic dose may not appear for 6-15 hours after exposure. More than 90% of deaths caused by mushroom poisonings are due to A. phalloides and related species. Target (s) : RNA polymerase II; RNA polymerase III; yeast RNA polymerase B; RNA polymerase I; certain plant RNA polymerases (e.g., plant RNA polymerase II (); DNA-directed DNA polymerase; DNA-directed RNA polymerase.

-20°C, protect from light,unstable in solution, ready to use.