Amino acid codesPeptaibols contain non-standard amino acid residues. Currently, there are four types contained within this database. The names, three and one letter codes for these unusual peptides are :
Undetermined residuesOccasionally, entries contain residues which weren't completely resolved. Two such types of entry occur in the database :
Where valine could not be distinguished from isovaline, records are marked Vx or Vxx.
N-terminal groupsThe N-terminus of a peptaibol is an an alkyl group, this is predominantly the acetyl group although other groups are known. The following descriptions appear within the database :
C-Terminal groupsPeptaibols have unusual C-terminal groups. Mainly, the c-terminal residue is reduced to an amino alochol. I.E. the COOH group becomes CH2OH.
The nomenclature we use for this is to treat the hydroxyl group as a seperate
entity, thus labelling valinol (hydroxylated valine) as Val-OH. This
system holds for all residues, even the unusual ones and the undetermined
Some peptaibols have other C-terminal groups, when these occur, they are included in a chemical nomenclature. Occasionally, a sequence contains the Tdol C-terminus, Tdol is an abbreviation for Trichodiaminol.
This nomenclature is adopted for the smooth running of the searching tools. Other nomenclatures for C-terminal groups will become apparent within the literature.