Stapled peptides: Magic bullets in nature's arsenal.

inhibitor of Mcl-1. Stewart et al. screened a library of stapled peptides based on the BH3 domains of BCL-2 family proteins (library depicted on left) and identified a selective inhibitor of MCL-1 (structure of the inhibitor in complex with Mcl-1 shown on the right), one of the anti-apoptotic family members that plays a key role in the survival of cancer cells. The peptide inhibitor, derived from the BH3 domain of MCL-1 itself, sensitizes cancer cells to caspase-dependent apoptosis, providing a novel tool to study and modulate this potential drug target. Cover art by Erin Boyle, based on artwork provided by Eric D. Smith. Article p595; News & Views p566 editorial 559 A practical philosophy