Cysteine proteinase. Hydrolyzes denatured natural substrates such as casein, hemoglobin, azoalbumin and azocasein with a high specific activity. Has little or no activity against synthetic substrates. Activated by thio-specific activators such as cysteine, beta-mercaptoethanol, DTT and glutathione. Inhibited by the thiol-specific inhibitors leupeptin, iodoacetamide, PCMB, NEM, mercuric chloride and sodium tetrathionate. Optimum pH is 7.5-8.0 with azoalbumin or hemoglobin as substrate. Active and stable from pH 2.0 to 12.0. Optimum temperature is 50 degrees Celsius with azoalbumin as substrate. Thermostable up to 70 degrees Celsius. Monomer. Laticifer. Belongs to the peptidase C1 family.