Analysis of peptaibol sequence composition: implications for in vivo synthesis and channel formation
- 111 Downloads
The sequence entries in the Peptaibol Database were analysed to provide information on compositional features of this unusual family of peptides. The non-standard amino acid α-aminoisobutyric acid represents almost 40% of the residues in all the known sequences. Glutamine is the only significant polar residue in peptaibols, and the position and number of these residues appear to be related to their functional properties as ion channels. Aromatic residues are clustered at the termini, which may contribute to stabilization of the peptide vertically within the bilayer. The peptide chain length is strongly weighted towards the longer members of the family (16–20 residues) and likely to be an important feature in their mode of action as transmembrane permeabilizers. The significant skewing towards even numbers of residues and the bias in pairwise distributions of amino acids have implications for the nature of the in vivo synthesis of these peptides via large non-ribosomal protein complexes.
KeywordsBioinformatics Database Ion channels Non-ribosomal synthesis Peptide structure
This work was supported, in part, by BBSRC grant B13586 to B.A.W.
- Nagaoka Y, Iida A, Kambara T, Asami K, Fujita T (1996) Role of 61n (7) in the ion channel forming, properties of the peptaibol trichosporin-B-VIa. Chem Commun 9:1079–1080Google Scholar
- Whitmore L, Chugh JK, Snook CF, Wallace BA (2003) The peptaibol database: a sequence and structure resource. J Pept Sci (in press)Google Scholar