Amanin is a
cyclic peptide
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty am ...
. It is one of the
amatoxin
Amatoxins are a subgroup of at least nine related cyclic peptide toxins found in three genera of deadly poisonous mushrooms (''Amanita'', '' Galerina'' and '' Lepiota'') and one species of the genus '' Pholiotina''. Amatoxins are very potent, as li ...
s, all of which are found in several members of the
mushroom
A mushroom or toadstool is the fleshy, spore-bearing Sporocarp (fungi), fruiting body of a fungus, typically produced above ground on soil or another food source. ''Toadstool'' generally refers to a poisonous mushroom.
The standard for the n ...
genus ''
Amanita
The genus ''Amanita'' contains about 600 species of agarics, including some of the most toxic known mushrooms found worldwide, as well as some well-regarded Edible mushroom, edible species (and many species of unknown edibility). The genus is re ...
''.
Toxicology
Like other amatoxins, amanin is an inhibitor of
RNA polymerase II
RNA polymerase II (RNAP II and Pol II) is a Protein complex, multiprotein complex that Transcription (biology), transcribes DNA into precursors of messenger RNA (mRNA) and most small nuclear RNA (snRNA) and microRNA. It is one of the three RNA pol ...
. Upon ingestion, it binds to the RNA polymerase II enzyme which completely prevents
mRNA synthesis, effectively causing
cytolysis
Cytolysis, or osmotic lysis, occurs when a cell bursts due to an osmotic imbalance that has caused excess water to diffuse into the cell. Water can enter the cell by diffusion through the cell membrane or through selective membrane channels ...
of
hepatocyte
A hepatocyte is a cell of the main parenchymal tissue of the liver. Hepatocytes make up 80% of the liver's mass.
These cells are involved in:
* Protein synthesis
* Protein storage
* Transformation of carbohydrates
* Synthesis of cholesterol, bi ...
s (liver cells) and
kidney cells.
See also
*
Mushroom poisoning
Mushroom poisoning is poisoning resulting from the ingestion of mushrooms that contain toxicity, toxic substances. Signs and symptoms, Symptoms can vary from slight Gastrointestinal tract, gastrointestinal discomfort to death in about 10 days. Mus ...
References
{{Toxins
Peptides
Amatoxins
Hepatotoxins