wehi-539 hydrochloride is a small-molecule inhibitor of bcl xl with ic50 value of 1.1 nm [1].wehi-539 was designed as a bcl-xl inhibitor with high affinity. it interacted with the binding groove of bcl-xl with kd value of 0.6 nm. in mef cells lacking mcl-1, wehi-539 induced apoptosis which was evidenced by the release of mitochondrial cytochrome c and caspase-3 processing. in bcl-xl overexpressed mef cells, wehi-539 showed ec50 value of 0.48 μm. wehi-539 also significantly induced apoptosis of the platelets purified from mice. besides that, wehi-539 cannot kill mef cells lacking bak because the cell death mediator bak is regulated by bcl-xl and mcl-1. [1].
[1]. lessene g, czabotar pe, sleebs be, et al. structure-guided design of a selective bcl-xl inhibitor. nature chemical biology, 2013, 9(6): 390-397.