Novel peptaibiotics identified from Trichoderma clade Viride.

This study focuses on the peptaibiome produced by different species of Trichoderma belonging to clade Viride: T. koningii SZMC 28387 (CBS 979.70), T. cf. strigosellum SZMC 28007 (TUCIM 4886/IQ 191), T. cf. dorothopsis SZMC 28390 (TUCIM 416/TUB F-597), T. cf. strigosellum SZMC 28391 (TUCIM 423/DAOM 230018), T. atroviride SZMC 28748 (IMI 206040), T. hamatum SZMC 28747 (TUCIM 2730) and T. cf. dorothopsis SZMC 28005 (TUCIM 4882/IQ 11). We were able to identify new compounds with similarity to already known groups of peptaibiotics, as well as completely newly discovered compounds using high-performance liquid chromatography (HPLC) -mass spectrometry (MS). From the 367 peptaibiotics identified, 216 are peptaibols and 111 are lipopeptaibols. Out of all peptaibols, 55 are previously known, while 161 are newly discovered. The new peptaibol subgroups Strigosellin A, B and Dorothopsin A, B are introduced. Furthermore, besides 38 previously known lipopeptaibols, 73 new lipopeptaibol sequences, named Lipostrigosellins and Lipohamatins are also reported. In addition, 41 peptaibol-like compounds with unusual C-terminus were also found. Out of the 7 strains examined, 5 produced both peptaibols and lipopeptaibols, while 2 only peptaibols. The well-known compound, Trikoningin KA V (TRK-V) also produced by T. koningii SZMC 28387 (CBS 979.70), was studied for its folding dynamics using accelerated molecular dynamics simulations (aMD) for understanding the plausible three-dimensional structures adopted by these peptaibols of clade Viride. We observed a propensity to form kinked, right-handed helical structures when simulated in an aqueous environment.