title: Isolation, sequence, and conformation of seven trichorzianines B from Trichoderma harzianum.
abstract: From the antagonistic fungus Trichoderma harzianum, a group of acidic new peptides, trichorzianines B (TB), was isolated in addition to neutral trichorzianines A (TA) previously studied. TA and TB exhibit various biological activities related to their membrane properties and a different behaviour of the two groups was noticed. As observed for other peptaibols, TB consist in a microheterogeneous mixture which was resolved into pure peptides by reversed-phase C18 HPLC. The sequence of the seven main isolated TB, namely TB IIa, TB IIIc, TB IVb, TB Vb, TB VIa, TB VIb, TB VII, was determined by the combined use of positive ion FAB mass spectrometry and 2D 1H n.m.r. spectroscopy, including COSY and NOESY experiments. TB differ from the corresponding TA only by the replacement of Gln 18 in the TA sequence by a glutamic acid. The 1H n.m.r. data suggested that the TB are mainly organized in an alpha helix.
authors.affiliation: Laboratory of Chemistry, UA 401 CNRS, National Museum of Natural History, Paris, France.
authors.forename: S
authors.initials: S
authors.lastname: Rebuffat
authors.forename: M
authors.initials: M
authors.lastname: el Hajji
authors.forename: P
authors.initials: P
authors.lastname: Hennig
authors.forename: D
authors.initials: D
authors.lastname: Davoust
authors.forename: B
authors.initials: B
authors.lastname: Bodo
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000302:isolation & purification; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods; D003904:Mitosporic Fungi / Q000032:analysis*; D008969:Molecular Sequence Data; D054848:Peptaibols; D010455:Peptides / Q000302:isolation & purification; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D014242:Trichoderma / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D054848:Peptaibols; D010455:Peptides; C058494:trichorzianine B