title: New Trichobrachins, 11-residue peptaibols from a marine strain of Trichoderma longibrachiatum.
abstract: A marine strain of Trichoderma longibrachiatum isolated from blue mussels (Mytilus edulis) was investigated for short peptaibol production. Various 11-residue peptaibols, obtained as microheterogenous mixtures after a chromatographic fractionation, were identified by positive mass spectrometry fragmentation (ESI-IT-MS(n), CID-MS(n) and GC/EI-MS). Thirty sequences were identified, which is the largest number of analogous sequences so far observed at once. Twenty-one sequences were new, and nine others corresponded to peptaibols already described. These peptaibols belonged to the same peptidic family based on the model Ac-Aib-xxx-xxx-xxx-Aib-Pro-xxx-xxx-Aib-Pro-xxol. They were named trichobrachin A when the residue in position 2 was an Asn, and trichobrachin C when it was a Gln. Major chromatographic sub-fractions, corresponding to purified peptaibols, were assayed for their cytotoxic activity. Trichobrachin A-IX and trichobrachin C exhibited the highest activities. There was an exponential relation between their relative hydrophobicity and their cytotoxicity on KB cells.
authors.affiliation: Université de Nantes, Nantes Atlantique Universités, SMAB-EA 2160, Faculté de pharmacie, BP 53508, F-44000 Nantes, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ruiz
authors.forename: Gaëtane
authors.initials: G
authors.lastname: Wielgosz-Collin
authors.forename: Laurence
authors.initials: L
authors.lastname: Poirier
authors.forename: Olivier
authors.initials: O
authors.lastname: Grovel
authors.forename: Karina Ethel
authors.initials: KE
authors.lastname: Petit
authors.forename: Mustapha
authors.initials: M
authors.lastname: Mohamed-Benkada
authors.forename: Thibaut Robiou
authors.initials: TR
authors.lastname: du Pont
authors.forename: John
authors.initials: J
authors.lastname: Bissett
authors.forename: Philippe
authors.initials: P
authors.lastname: Vérité
authors.forename: Gilles
authors.initials: G
authors.lastname: Barnathan
authors.forename: Yves François
authors.initials: YF
authors.lastname: Pouchus
mesh_terms: D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007624:KB Cells; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D014242:Trichoderma / Q000737:chemistry*
chemical_list: D010455:Peptides