Alamethicin
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Names | |
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IUPAC name
N-acetyl-2-methylalanyl-L-prolyl-2-methylalanyl-L-alanyl-2-methylalanyl-L-alanyl-L-glutaminyl-2-methylalanyl-L-valyl-2-methylalanylglycyl-D-leucyl-2-methylalanyl-L-prolyl-L-valyl-2-methylalanyl-2-methylalanyl-L-α-glutamyl-N1-[(1S)-1-benzyl-2-hydroxyethyl]-L-glutamamide
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Identifiers | |
27061-78-5 | |
ChEMBL | ChEMBL438243 |
ChemSpider | 17288702 |
Jmol 3D model | Interactive image Interactive image |
PubChem | 16132042 |
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Properties | |
C92H150N22O25 | |
Molar mass | 1964.31 g/mol |
Appearance | Off white solid |
Melting point | 255 to 270 °C (491 to 518 °F; 528 to 543 K) |
Insoluble | |
Solubility in DMSO, methanol, ethanol | Soluble |
Vapor pressure | {{{value}}} |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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verify (what is ?) | |
Infobox references | |
Alamethicin is a peptide antibiotic, produced by the fungus Trichoderma viride. It belongs to peptaibol peptides which contain the non-proteinogenic amino acid residue Aib (2-aminoisobutyric acid). This residue strongly induces formation of alpha-helical structure. The peptide sequence is:
Ac-Aib-Pro-Aib-Ala-Aib-Ala-Gln-Aib-Val-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-Glu-Gln-Phl
(Ac = acetyl, Phl = phenylalaninol, Aib = 2-Aminoisobutyric acid)
In cell membranes, it forms voltage-dependent ion channels by aggregation of four to six molecules.
Biosynthesis
Alamethicin biosynthesis is hypothesized to be catalyzed by alamethicin synthase, a Nonribosomal peptide synthase (NRPS) first isolated in 1975.[2] Although there are several sequences of the alamethicin peptide accepted,[3] evidence suggests these all follow the general NRPS mechanism [4] with small variations at select amino acids.[5] Beginning with the acylation of the N terminal of the first aminoisobutiric acid on the ALM synthase enzyme by Acetyl-CoA,[6] this is followed by the sequential condensation of amino acids by each modular unit of the synthetase.[7] Amino acids are initially adenylated by an “adenylylation” (A) domain before being attached by a thioester bond to an Acyl Carrier Protein-like Peptidyl carrier protein.[8] The growing chain is attached to the amino acid bearing PCP by the "condensation" (C) domain, followed by another round of the same reactions by the next module.[8]
Assembly is completed by the addition of phenylalaninol, an unusual amino acid-like substrate.[9] Following addition of phenylalaninol the completed peptide chain is cleaved by the thioesterase domain, cleaving the thioester bond and leaving an alcohol.
References
- ↑ Alamethicin product page from Fermentek
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
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Further reading
- Lua error in package.lua at line 80: module 'strict' not found.
- Explore structures of Alamethicin at the protein data bank
- Alamethicin in Norine
- From "A voltage-gated ion channel model inferred from the crystal structure of alamethicin at 1.5-A resolution." Lua error in package.lua at line 80: module 'strict' not found.
- The History of Alamethicin: A Review of the Most Extensively Studied Peptaibol [1]
- ↑ Lua error in package.lua at line 80: module 'strict' not found.