Leptomycin B is the dominant and most studied member of the leptomycin class isolated from selected Streptomyces strains. Leptomycin B is a nanomolar active and specific nuclear export inhibitor. Its target is CRM1/exportin1 a protein in the nuclear export sequence (NES). Examples of proteins affected are c-Abl, cyclin B1, HIV-1 Rev, IκB, MPF, MAP/ERK, MDM2/p53, NF-κB/IκB7 and PKA. Export of many RNAs are also inhibited e.g. COX-2 and c-FOS mRNA. In addition Leptomycin B shows antifungal and antibacterial and potent antitumour activities.
Solubility:Soluble in ethanol or methanol. Poor water solubility. Ethanol is recommended. Unstable in DMSO.
Storage and Stability:Stable for 6 months after receipt at -20°C.
Related to: Anguinomycin A, Leptomycin A, Kazusamycin A, Kazusamycin B
