TABLE 5.

Effect of E-64d on cathepsin activity and viability of HeLa cells

HeLa S3 cells were continuously treated with E-64d (EST), a cell-permeable precursor of inhibitor of cysteine proteases E-64. Activity of cathepsins was measured as in Table 4 in extracts of cells harvested 6 h after the start of the treatment. Cell viability was measured with Alamar Blue 48 h after the treatment. Cathepsin activity is normalized to the amount of protein in extracts used for the measurements of activity and expressed relative to the value in mock-treated controls. Values are averages ± S.E. of two independent measurements.