Alamethicin
Alamethicin is a peptide antibiotic, produced by trichoderma viride. It contains the non-proteinogenic amino acid 1-amino isobutyric acid (Aib), which strongly induces helical peptide structures. 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)
In cell membranes, it forms voltage dependent on ion channels by aggregation of four to six molecules.