New Sequences, Constituents, and Producers of Peptaibiotics: An Updated Review

Abstract

To date, 18 genera of imperfect and ascomycetous fungi have been recognized to produce ca. 700 individual sequences of peptaibiotics. These are linear polypeptide antibiotics which i) have a molecular weight between 500 and 2,200 Dalton, thus containing 5-21 residues; ii) show a high content of alpha-aminoisobutyric acid; iii) are characterized by the presence of other nonproteinogenic amino acids and/or lipoamino acids; iv) possess an acylated N-terminus, and v) have a C-terminal residue that, in most of them, consists of a free or acetylated amide-bonded 1,2-amino alcohol, but might also be an amine, amide, free amino acid, 2,5-dioxopiperazine, or sugar alcohol. From April 2003 until present, ca. 300 new individual sequences of peptaibiotics have been published in the literature, but most of them have not yet been included in databases. To summarize these new sequences and novel constituents, as well as to introduce fungal species hitherto unknown as producers of peptaibiotics, the relevant literature is reviewed. Furthermore, ecophysiological and taxonomic aspects of the producing fungi are discussed.

Recent Results in Alamethicin Research

“…ALM consists of 20 amino acid residues with phenylalaninol (Pheol) at the C-terminus and an acetylated N-terminus. The originally described compound is composed of two major groups named ALM F30 and ALM F50 and a minor component (ALM F20) based on their retention factor values in tissue liquid chromatography on acidic silica gel [2].…”

Peptaibiomics: Towards a Myriad of Bioactive Peptides Containing Cα‐Dialkylamino Acids?

“…Although not yet reported in literature, Degenkolb et al [2] claimed the detection of very short chain ( < 5 residues) peptaibiotics that may represent drastically truncated sequences.…”

“…The majority of Aib-containing peptides carries a C-terminal residue representing a 2-amino alcohol, and this subgroup is, therefore, referred to as peptaibols [2] [3]. In strongly lipophilic peptaibols, the N-terminus is acylated by octanoic, decanoic, or cis-dec-4-enoic acid, and these are named lipopeptaibols [4].…”

“…To our present knowledge, this compound, 2-amino-6-hydroxy-4-methyl-8-oxodecanoic acid (AHMOD), has only been detected in this subfamily. A fourth subfamily comprises all other linear peptaibiotics that cannot be classified in any of the other three preceding subfamilies [2]. Recently, a fifth subfamily has been introduced.…”

“…The N-terminal Pro residue of the texenomycins is protected by a b-keto-2-methyltetradecanoyl (MOTDA) residue, whereas arginol (Argol) is found as a so far unique C-terminal constituent [144]. However, ecophysiological and chemotaxonomic considerations rather suggest an unrecognized infection of the investigated strain by a mycoparasite of basidiomycete affiliation that could be attributed as the producer of these peptaibiotics [2] [122]. Lipohexin, an inhibitor of prolyl endopeptidase, representing a six-residue N-terminal deletion sequence of texenomycin, was isolated from three fungal strains, originally identified as Moeszia lindtneri HKI-0054, and two Paecilomyces sp., HKI-0055 and HKI-0096 [145] [146].…”