Figure 6.

Determination of the caspase-3 cleavage sites in Cas using site-directed mutagenesis. (A) Cas mutants containing point mutations replacing Asp (DVPD⁴¹⁶ and/or DSPD⁷⁴⁸) with Glu were translated in vitro and incubated with extracts (20 μg) prepared from bacterial cells overexpressing recombinant caspase-3. Mutations at D416 and/or D748 are able to block Cas cleavage at those sites. Molecular mass standards are shown by the arrowheads on the left. Molecular masses of the cleavage products are shown by the arrows on the right.