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| Names | |
|---|---|
| IUPAC name
N-acetyl-2-methylalanyl-L-prolyl-2-methylalanyl-L-alanyl-2-methylalanyl-L-alanyl-L-glutaminyl-2-methylalanyl-L-valyl-2-methylalanylglycyl-L-leucyl-2-methylalanyl-L-prolyl-L-valyl-2-methylalanyl-2-methylalanyl-L-α-glutamyl-N1-[(1S)-1-benzyl-2-hydroxyethyl]-L-glutamamide | |
| Identifiers | |
3D model (JSmol) |
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| ChEMBL | |
| ChemSpider |
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| ECHA InfoCard | 100.121.626 
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PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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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 | |
| SolubilityinDMSO, methanol, ethanol | Soluble |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Alamethicin is a channel-forming 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
where Ac = acetyl, Phl = phenylalaninol, and Aib = 2-Aminoisobutyric acid.
Incell membranes, it forms voltage-dependent ion channels by aggregation of four to six molecules.
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.[citation needed]
