Tubulysin G is a highly cytotoxic peptide isolated from the myxobacterial species Archangium geophyra and Angiococcus disciformis. Tubulysin displays extremely potent cytotoxic activity in mammalian cells, including multidrug-resistant cell lines, with IC50 values in the lower nanomolar range[1]. Tubulysin G is a cytotoxic activity tubulysin which inhibits tubulin polymerization and leads to cell cycle arrest and apoptosis[2].
[1]. Kubicek K, et al. The tubulin-bound structure of the antimitotic drug tubulysin. Angew Chem Int Ed Engl. 2010 Jun 28;49(28):4809-12. [2]. Vlahov IR, et al. Acid mediated formation of an N-acyliminium ion from tubulysins: a new methodology for the synthesis of natural tubulysins and their analogs. Bioorg Med Chem Lett. 2011 Nov 15;21(22):6778-81.