Description
Product Usage Information
Leptomycin B is supplied as a 200 μM solution in ethanol within a sealed container. In order to minimize evaporation, ensure vial is tightly closed at all times except when actively diluting or pipetting. It is also recommended that the LMB vial be kept on ice when in use to help prevent evaporation. All dilutions, except the final dilution, must be performed in ethanol. Final dilutions can be performed in culture media. Working concentrations and length of treatment can vary depending on the desired effect, but 1-20 nM for 3 hours generally inhibits most nuclear export. Soluble and stable in ethanol. Leptomycin B is not stable in DMSO; do not dilute in DMSO. Stability Warning: LMB in any quantity is unstable when dried down into a film. Thus, under no circumstances should the solvent be removed from solutions of LMB because rapid decomposition and loss of recoverable material will result.
Storage
Store solution at -20ºC. Protect from light. If stored and handled appropriately, it will be stable for 12 months.
Background
Leptomycin B (LMB), originally discovered and utilized as a potent anti-fungal antibiotic from Streptomyces sp., has more recently been identified to inhibit nuclear export of proteins and RNA containing a Nuclear Export Sequence (NES) (1). The mechanism behind LMB's potent inhibition is achieved by specifically binding to chromosomal region maintenance (CRM)/exportin 1 protein; CRM1 binds to ribonuclear proteins containing the NES (1,2). LMB has also been reported to inhibit the degradation and subsequently lead to accumulation of p53 within the nucleus (3) and has demonstrated specific anti-tumor properties, although toxic, at high doses (1-3).
Alternate Names
anti-tumor; chromosomal region maintenance; CRM; CRM1; exportin 1; exportin1; Inhibition; Inhibitor; LMB; Nuclear Export Inhibition; p53
