Front line defenders of the ecological niche! Screening the structural diversity of peptaibiotics from saprotrophic and fungicolousTrichoderma/Hypocreaspecies.
Approximately 950 individual sequences of non-ribosomally biosynthesised peptides are produced by the genusTrichoderma/Hypocreathat belong to a perpetually growing class of mostly linear antibiotic oligopeptides, which are rich in the non-proteinogenicα-aminoisobutyric acid (Aib). Thus, they are comprehensively named peptaibiotics. Notably, peptaibiotics represent ca. 80 % of the total inventory of secondary metabolites currently known fromTrichoderma/Hypocrea. Their unique membrane-modifying bioactivity results from amphipathicity and helicity, thus making them ideal candidates in assisting both colonisation and defence of the natural habitats by their fungal producers. Despite this, reports on the in vivo-detection of peptaibiotics have scarcely been published in the past. In order to evaluate the significance of peptaibiotic production for a broader range of potential producers, we screened nine specimens belonging to seven hitherto uninvestigated fungicolous or saprotrophicTrichoderma/Hypocreaspecies by liquid chromatography coupled to electrospray high resolution mass spectrometry. Sequences of peptaibiotics found were independently confirmed by analysing the peptaibiome of pure agar cultures obtained by single-ascospore isolation from the specimens. Of the nine species examined, five were screened positive for peptaibiotics. A total of 78 peptaibiotics were sequenced, 56 (=72 %) of which are new. Notably, dihydroxyphenylalaninol andO-prenylated tyrosinol, twoC-terminal residues, which have not been reported for peptaibiotics before, were found as well as new and recurrent sequences carrying the recently described tyrosinol residue at theirC-terminus. The majority of peptaibiotics sequenced are 18- or 19-residue peptaibols. Structural homologies with 'classical representatives' of subfamily 1 (SF1)-peptaibiotics argue for the formation of transmembrane ion channels, which are prone to facilitate the producer capture and defence of its substratum.
Bioresources Project Group, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Winchesterstrasse 2, 35394 Giessen, Germany. Present Address: AB SCIEX Germany GmbH, Landwehrstrasse 54, 64293 Darmstadt, Germany.
Christian R
CR
Röhrich
Department of Systematic and Evolutionary Botany, Faculty Centre of Biodiversity, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
Walter M
WM
Jaklitsch
Department of Systematic and Evolutionary Botany, Faculty Centre of Biodiversity, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
Hermann
H
Voglmayr
Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Building 221, 2800 Kgs. Lyngby, Denmark. Present Address: Danish Emergency Management Agency, Universitetsparken 2, 2100 Copenhagen, Denmark.
Anita
A
Iversen
Bioresources Project Group, Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Winchesterstrasse 2, 35394 Giessen, Germany; Interdisciplinary Research Centre for BioSystems, Land Use and Nutrition (IFZ), Department of Applied Entomology, Institute of Phytopathology and Applied Zoology (IPAZ), University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
Andreas
A
Vilcinskas
Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Building 221, 2800 Kgs. Lyngby, Denmark.
Kristian Fog
KF
Nielsen
Department of Systems Biology, Technical University of Denmark, Søltofts Plads, Building 221, 2800 Kgs. Lyngby, Denmark.
Ulf
U
Thrane
Biochemistry and Molecular Biology OE 2, Institute of Chemistry, Technical University of Berlin, Franklinstrasse 29, 10587 Berlin, Germany.
Hans
H
von Döhren
Interdisciplinary Research Centre for BioSystems, Land Use and Nutrition (IFZ), Department of Food Sciences, Institute of Nutritional Science, University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
Hans
H
Brückner
Interdisciplinary Research Centre for BioSystems, Land Use and Nutrition (IFZ), Department of Applied Entomology, Institute of Phytopathology and Applied Zoology (IPAZ), University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany thomas.degenkolb@ernaehrung.uni-giessen.de.
Thomas
T
Degenkolb
Aib peptides; HPLC/QTOF-ESI-HRMS; Hypocrea; Metabolite profiling; Peptaibiotics; Peptaibols; Trichoderma