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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 little as half a mushroom cap can cause severe liver injury if swallowed. Structure The compounds have a similar structure, that of eight amino-acid residues arranged in a conserved macrobicyclic motif (an overall pentacyclic structure when counting the rings inherent in the proline and tryptophan-derived residues); they were isolated in 1941 by Heinrich O. Wieland and Rudolf Hallermayer. All amatoxins are cyclic peptides that are synthesized as 35-amino-acid proproteins, from which the final eight amino acids are cleaved by a prolyl oligopeptidase. The schematic amino acid sequence of amatoxins is Ile-Trp-Gly-Ile-Gly-Cys-Asn-Pro with cross-linking between Trp and Cys via the sulfoxide (S=O) moiety and hydroxylation in variants of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Amatoxins Generic Strucuture
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 little as half a mushroom cap can cause severe liver injury if swallowed. Structure The compounds have a similar structure, that of eight amino-acid residues arranged in a conserved macrobicyclic motif (an overall pentacyclic structure when counting the rings inherent in the proline and tryptophan-derived residues); they were isolated in 1941 by Heinrich O. Wieland and Rudolf Hallermayer. All amatoxins are cyclic peptides that are synthesized as 35-amino-acid proproteins, from which the final eight amino acids are cleaved by a prolyl oligopeptidase. The schematic amino acid sequence of amatoxins is Ile-Trp-Gly-Ile-Gly-Cys-Asn-Pro with cross-linking between Trp and Cys via the sulfoxide (S=O) moiety and hydroxylation in variants of the mol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lepiota
''Lepiota'' is a genus of gilled mushrooms in the family Agaricaceae. All ''Lepiota'' species are ground-dwelling saprotrophs with a preference for rich, calcareous soils. Basidiocarps (fruit bodies) are agaricoid with whitish spores, typically with scaly caps and a ring on the stipe. Around 400 species of ''Lepiota'' are currently recognized worldwide. Many species are poisonous, some lethally so. Taxonomy History ''Agaricus'' section ''Lepiota'' was originally published in 1797 by South African-born mycologist Christian Hendrik Persoon. It was subsequently raised to the rank of genus by Samuel Frederick Gray. As originally conceived, the genus was a mix of agarics with rings on their stems, including species now placed in '' Armillaria'', '' Cortinarius'', and '' Pholiota''. In 1822, however, the influential Swedish mycologist Elias Magnus Fries restricted ''Lepiota'' to white-spored, ringed agarics. Based on macro- and micromorphology, later authors gradually refi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Amaninamide
Amaninamide is a cyclic peptide. It is one of the amatoxins, all of which are found in several members of the mushroom genera ''Amanita'', ''Lepiota'' and ''Galerina''. It differs from alpha-amanitin in lacking the hydroxyl group on tryptophan. This alters its UV absorption spectrum but not its toxicity. Toxicology Like other amatoxins, amaninamide is an inhibitor of RNA polymerase II. Upon ingestion, it binds to the RNA polymerase II enzyme which completely prevents mRNA synthesis, effectively causing cytolysis of hepatocytes (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 External linksAmatoxins REVISED(German) {{Toxins Peptides Amatoxins Hepatotoxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Amanullin
Amanullin is a cyclic peptide. It is an amatoxin, all of which are found in several members of the mushroom genus ''Amanita''. The oral of amanullin is approximately 20 mg/kg in mice; however, it is non-toxic in humans. Toxicology Like other amatoxins, amanullin 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 .... Amanullin has a species dependent and specific attraction to the enzyme RNA polymerase II. Upon ingestion, it binds to the RNA polymerase II enzyme, effectively causing cytolysis of hepatocytes (liver cells). See also * Mushroom poisoning References External linksAmatoxins REVISED(German) {{Toxins Peptides Amatoxins Hepatotoxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Proamanullin
Promanullin is a cyclic nonribosomal peptide. It is an amatoxin, all of which are found in the mushroom genus ''Amanita''. Toxicology Like other amatoxins, proamanullin is an inhibitor of RNA polymerase II. Promanullin has a specific attraction to the enzyme RNA polymerase II. Upon ingestion, it binds to the RNA polymerase II enzyme, effectively causing cytolysis of hepatocytes (liver 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 External linksAmatoxins REVISED {{Toxins Peptides Amatoxins Hepatotoxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Amanin
Amanin is a cyclic peptide. It is one of the amatoxins, all of which are found in several members of the mushroom genus ''Amanita''. Toxicology Like other amatoxins, amanin is an inhibitor of RNA polymerase II. Upon ingestion, it binds to the RNA polymerase II enzyme which completely prevents mRNA synthesis, effectively causing cytolysis of hepatocytes (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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Amanullinic Acid
Amanullinic acid is a cyclic nonribosomal peptide. It is an amatoxin, all of which are found in several members of the mushroom genus ''Amanita''. Amanullinic acid is relatively non-toxic( oral >20 mg/kg in mice). Toxicology Like other amatoxins, amanullinic acid is an inhibitor of RNA polymerase II. 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 External linksAmatoxins REVISED {{Toxins Peptides Amatoxins Hepatotoxins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 polymerase, RNAP enzymes found in the nucleus of eukaryote, eukaryotic cells. A 550 kDa complex of 12 subunits, RNAP II is the most studied type of RNA polymerase. A wide range of transcription factors are required for it to bind to upstream gene promoter (biology), promoters and begin transcription. Discovery Early studies suggested a minimum of two RNAPs: one which synthesized rRNA in the nucleolus, and one which synthesized other RNA in the nucleoplasm, part of the nucleus but outside the nucleolus. In 1969, biochemists Robert G. Roeder and William J. Rutter, William Rutter discovered there are total three distinct nuclear RNA polymerases, an additional RNAP that was responsible for transcription of some kind of RNA in the nucleoplasm. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
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 responsible for approximately 95% of fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own. The most potent toxin present in these mushrooms is . The genus also contains many edible mushrooms, but mycologists discourage mushroom hunters, other than experts, from selecting any of these for human consumption. Nonetheless, in some cultures, the larger local edible species of ''Amanita'' are mainstays of the markets in the local growing season. Samples of this are ''Amanita zambiana'' and other fleshy species in central Africa, ''Amanita basii, A. basii'' and similar species in Mexico, ''Amanita caesarea, A. caesarea'' and the "Blusher" ''Amanita rubescens, A. rubescens'' in Europe, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cyclic Peptide
Cyclic peptides are polypeptide chains which contain a circular sequence of bonds. This can be through a connection between the amino and carboxyl ends of the peptide, for example in cyclosporin; a connection between the amino end and a side chain, for example in bacitracin; the carboxyl end and a side chain, for example in colistin; or two side chains or more complicated arrangements, for example in alpha-amanitin. Many cyclic peptides have been discovered in nature and many others have been synthesized in the laboratory. Their length ranges from just two amino acid residues to hundreds. In nature they are frequently antimicrobial or toxic; in medicine they have various applications, for example as antibiotics and immunosuppressive agents. Thin-layer chromatography, Thin-Layer Chromatography (TLC) is a convenient method to detect cyclic peptides in crude extract from bio-mass. Classification Cyclic peptides can be classified according to the types of bonds that comprise the ring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cyclic Peptides
Cyclic peptides are polypeptide chains which contain a circular sequence of bonds. This can be through a connection between the amino and carboxyl ends of the peptide, for example in cyclosporin; a connection between the amino end and a side chain, for example in bacitracin; the carboxyl end and a side chain, for example in colistin; or two side chains or more complicated arrangements, for example in alpha-amanitin. Many cyclic peptides have been discovered in nature and many others have been synthesized in the laboratory. Their length ranges from just two amino acid residues to hundreds. In nature they are frequently antimicrobial or toxic; in medicine they have various applications, for example as antibiotics and immunosuppressive agents. Thin-Layer Chromatography (TLC) is a convenient method to detect cyclic peptides in crude extract from bio-mass. Classification Cyclic peptides can be classified according to the types of bonds that comprise the ring. *Homodetic cyclic pept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Galerina
''Galerina'' is a genus of small brown-spore saprobic mushroom-bearing fungi, with over 300 species found throughout the world from the far north to remote Macquarie Island in the Southern Ocean. The genus is most noted for some extremely poisonous species which are occasionally confused with hallucinogenic species of ''Psilocybe''. ''Galerina'' mushrooms are typically small and hygrophanous, with a slender and brittle stem. They are often found growing on wood, and when on the ground have a preference for mossy habitats. ''Galerina'' means ''helmet-like''. Taxonomic definition The genus ''Galerina'' is defined as small mushrooms of mycenoid stature, that is, roughly similar in form to ''Mycena'' species: a small conical to bell-shaped cap, and gills attached to a long and slender cartilaginous stem. Species have a pileipellis that is a cutis, and ornamented spores that are brown in deposit, where the spore ornamentation comes from an extra spore covering. Description ''Ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
