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Alamethicin I

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It is produced by the strain of Trichoderma viride. It was mainly resistant to gram-positive bacteria and pear-type tetrahymena, and inhibited KB cells.

Functional Peptides
Catalog number
CAS number
Molecular Formula
Molecular Weight
Alamethicin I
(4S)-4-[[2-[[2-[[(2S)-2-[[(2S)-1-[2-[[(2S)-2-[[2-[[2-[[(2S)-2-[[2-[[(2S)-2-[[(2S)-2-[[2-[[(2S)-2-[[2-[[(2S)-1-(2-acetamido-2-methylpropanoyl)pyrrolidine-2-carbonyl]amino]-2-methylpropanoyl]amino]propanoyl]amino]-2-methylpropanoyl]amino]propanoyl]amino]-5-amino-5-oxopentanoyl]amino]-2-methylpropanoyl]amino]-3-methylbutanoyl]amino]-2-methylpropanoyl]amino]acetyl]amino]-4-methylpentanoyl]amino]-2-methylpropanoyl]pyrrolidine-2-carbonyl]amino]-3-methylbutanoyl]amino]-2-methylpropanoyl]amino]-2-methylpropanoyl]amino]-5-[[(2S)-5-amino-1-[[(2S)-1-hydroxy-3-phenylpropan-2-yl]amino]-1,5-dioxopentan-2-yl]amino]-5-oxopentanoic acid
Alamethicin; Alamethicin gamma; Alamethicin F 30; Antibiotic U 22324; F-50; U 22324; Ac-Aib-Pro-Aib-Ala-Aib-Ala-Gln-Aib-Val-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-Glu-Gln-Phe-ol; L-Glutamamide, 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-alpha-glutamyl-N1-(1-(hydroxymethyl)-2-phenylethyl)-, (S)-; ALM
Related CAS
27061-78-5 (Alamethicin)
White Crystal
1.240±0.1 g/cm3
Melting Point
259-260 °C
Boiling Point
2090.0±65.0°C at 760 mmHg
Store at 2-8°C
Soluble in DMSO, Ethanol
InChI Key
Canonical SMILES
1. NMR studies on the conformation, stability and dynamics of alamethicin in methanol
Yoshinori Miura Eur Biophys J . 2020 Jan;49(1):113-124. doi: 10.1007/s00249-019-01418-8.
Alamethicin is an antibiotic peptide comprising 20 amino acid residues and functions as an ion channel in biological membranes. Natural alamethicins have a variety of amino acid sequences. Two of them, used as a mixed sample in this study, are: UPUAUAQUVUGLUPVUUQQO and UPUAUUQUVUGLUPVUUQQO, where U and O represent α-aminoisobutyric acid and phenylalaninol, respectively. As indicated, only the amino acid at position six differs, and the two alamethicins are referred to as alamethicin-A6 and -U6, respectively. The conformation and thermal stability of alamethicin-A6 and -U6 in methanol were examined using proton nuclear magnetic resonance (NMR) spectroscopy. Both alamethicins form an α-helix between the 2nd and 11th residues. The N-terminal, 19th and C-terminal residues take a non-helical conformation. The structure between the 12th and 18th residues has not been well determined due to the absence of cross peaks in the two-dimensional NMR data. The α-helices are maintained up to 54 °C at least. In contrast to these similarities, it has been found that the length of the α-helix of alamethicin-U6 is somewhat shorter than that of alamethicin-A6, the intra-molecular hydrogen bonds formed by the amide proton of the seventh residue is much more thermally stable for alamethicin-U6 than for alamethicin-A6, and the C-terminal residue of alamethicin-U6 has higher mobility than that of alamethicin-A6. The mobility of the N- and C-terminal residues is discussed on the basis of a model chain which consists of particles connected by rigid links, and the physiological significance of the mobility is emphasized.
2. Communication: Alamethicin can capture lipid-like molecules in the membrane
Victoria N Syryamina, Sergei A Dzuba, Ekaterina F Afanasyeva J Chem Phys . 2017 Jan 7;146(1):011103. doi: 10.1063/1.4973703.
Alamethicin (Alm) is a 19-mer antimicrobial peptide produced by fungus Trichoderma viride. Above a threshold concentration, Alm forms pores across the membrane, providing a mechanism of its antimicrobial action. Here we show that at a small concentration which is below the threshold value, Alm participates in formation of nanoscale lipid-mediated clusters of guest lipid-like molecules in the membrane. These results are obtained by electron spin echo (ESE) technique-a pulsed version of electron paramagnetic resonance-on spin-labeled stearic acid in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine bilayer with Alm added at 1/200 peptide-to-lipid ratio. ESE decay measurements are interpreted assuming that stearic acid molecules in the membrane are assembling around the Alm molecule. One may suggest that this Alm capturing effect on the guest lipid-like molecules could be important for the peptide antimicrobial action.
3. Alamethicin and related membrane channel forming polypeptides
M K Mathew, P Balaram Mol Cell Biochem . 1983;50(1):47-64. doi: 10.1007/BF00225279.
Alamethicin and several related microbial polypeptides, which contain a high proportion of alpha-aminoisobutyric acid (Aib) residues, possess the ability to modify the permeability properties of phospholipid bilayer membranes. Alamethicin induces excitability phenomena in model membranes and has served as an excellent model for the study of voltage sensitive transmembrane channels. This review summarizes various aspects of the structural chemistry and membrane modifying properties of alamethicin and related Aib containing peptides. The presence of Aib residues in these sequences, constrains the polypeptides to 3(10) or alpha-helical conformations. Functional membrane channels are formed by aggregation of cylindrical peptide helices, which span the lipid bilayer, forming a scaffolding for an aqueous column across the membrane. After consideration of the available data on the conductance characteristics of alamethicin channels, a working hypothesis for a channel model is outlined. Channel aggregates in the lipid phase may be stabilized by intermolecular hydrogen bonding, involving a central glutamine residue and also by interactions between the macro-dipoles of proximate peptide helices. Fluctuations between different conductance states are rationalized by transitions between states of different aggregation and hence altered dimensions of the aqueous core or by changes in net dipole moment of the aggregate. Ion fluxes through the channel may also be affected by the electric field within the aqueous core.
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