Different concentrations of lamin A protein (3-400 nM) were digested with 20 nM caspase-6 in caspase cleavage buffer for 15, 30, 45, and 60 minutes at 37uC. The reactions were stopped by shock-freezing, and thawed samples were analysed with the Mesoscale ELISA system. The cleavage rate was calculated at each lamin concentration and plotted against the concentration of Lamin A protein to calculate the Km and Kcat (Fig. S2 ).