“…Cystein proteases are the most abundant proteases present in E histolytica [54,62]. Although several authors [20,59,62] have described a wide variety of proteases with different electrophoretic mobilities, three molecular sizes are the most frequently described: 16 kDa [39], [26][27][28][29]38,59,60,70,77,78] and 56 kDa [20,29,62,70,71]. All of them are inhibited by thiol proteinase inhibitors, especially iodoacetic acid, p.HMB and chicken cystatin, and less effectively by leupeptin, N-ethylmaleimide (NEM), l-chloro-3-tosylamido-7-amino-2-heptanone hydrochloride (TLCK) and antipain [7,8,29,38,39,62,77,78].…”