Influence of different protease inhibitors on the proteolytic activity of HTRA1.

The protease inhibitors were added separately to an incubation mixture containing 5 µg β-casein and 0.5 µg HTRA1 at 37°C. Aliquots were taken at time 0 h and after 1 h incubation at 37°C and analysed by RP-HPLC. Percentage degradation of β-casein was calculated on the height basis from the UV chromatogram obtained at a wavelength of 205 nm, normalised to the height of the β-casein peak at time 0 h (mean of three replicates). As control, β-casein was incubated with HTRA1 without addition of an inhibitor. Compared with the control, protease activity of HTRA1 was not significantly inhibited by the inhibitors tested in this study. Only EDTA seems to slow slightly the proteolytic reaction.
Influence of different protease inhibitors on the proteolytic activity of HTRA1.