Figure 8.6.

Procaspase activation by small molecules. (A) Four small molecules have been reported to act as allosteric activators of procaspases; PAC-1 (Putt et al., 2006), 1541 (Wolan, Zorn, Gray, & Wells, 2009), compound-42 (Schipper, MacKenzie, Sharma, & Clark, 2011), and compound-2 (Vickers et al., 2013). (B) Mechanism of procaspase activation by 1541 nanofibrils. A small amount of active caspase (labeled with asterisk) is already present in E. coli-purified procaspase samples. The nanofibrils serve as a scaffold for colocalization of active caspase with the proenzyme, leading to activation. Figure (B) is adapted with permission from Zorn, Wille, Wolan, and Wells, (2011). Copyright (2011) American Chemical Society.