Inhibition activities against cathepsin B, C, L and S by recombinant cysteine protease inhibitor <i>Ascaris lumbricoides</i> (Al-CPI).

<p>Cathepsins were incubated with the fluorogenic substrates in the absence or presence of serially diluted Al-CPI in appropriate buffer for 15 min. and reaction was stopped with stopping buffer. The amount of product was measured fluorometrically with excitation at 360 nm and emission at 460 nm. The inhibitory activity of Al-CPI was expressed as a percentage of the total activity detected in reactions without Al-CPI. The half maximal inhibitory concentration (IC₅₀) values of Al-CPI based on initial reaction velocities were determined by nonlinear regression analysis and are shown on each plot. Data shown are from one of three experiments.