Structural asymmetry of procaspase-7 bound to a specific inhibitor

The first structural analysis of a procaspase-7 variant bound to a specific inhibitor, Ac-DEVD-CHO, revealed a structural asymmetry that the two L2 loops in homodimeric procaspase-7 served as inherent L2 and L2' loops forming a complete active site in one monomer, which may be responsible to a basal activity level, but not in the other. This provides insight into the basal activity of procaspase-7 and the folding mechanism during caspase-7 activation.