Silva RN et al. Metabolic Diversity of Trichoderma. (2014) Megjelent: Biotechnology
and Biology of Trichoderma pp. 363-376 [Idézéskapcsolat:23356088]
They contain high amounts of the nonproteinogenic α-aminoisobutyric acid, and other
nonproteinogenic amino acids can be found in peptaibols, such as l- and isovaline,
cis and trans-4-lhydroxyproline, cis-4-l-methylproline, β-hydroxy-lleucine, β-alanine,
l-pipecolic acid, α-ethyl-norvaline, and 2-amino-4-methyl-6-hydroxy-8-oxoecanoic acid
(Szekeres et al., 2005).
Peptaibols are defined as linear or cyclic polypeptide antibiotics. They may be classified
according to the number of residues: long-chain peptides with 18–20 amino acid residues,
exemplified by alamethicins or trichorzianins with a single central Pro; the short-chain
peptides with 11–16 residues, exemplified by harzianins or zervamicins with a high
proportion of Pro; the lipopeptaibols with 7 or 11 residues, exemplified by trichogin
A IV with a high Gly content; and the very short-chain peptides with ≤5 residues,
exemplified by peptaibolin
(Krause et al., 2007; Szekeres et al., 2005).
The loss of peptaibol production demonstrated by experiments with tex1 knockout mutants
reflects the availability of conjugate substrates rather than the existence of multiple,
nonribosomal peptide synthetases, each responsible for the production of one member
of the mixture (Szekeres et al., 2005).