Journal of Tropical Medicine / 2013 / Article / Tab 1

Review Article

Proteases from Entamoeba spp. and Pathogenic Free-Living Amoebae as Virulence Factors

Table 1

Cysteine proteases of Entamoeba histolytica that degrade host proteins and their implication in virulence.

Tissue or protein PurifiedNameMr (kDa) Comment, localizationReference

ECM components

 CollagenYesEhCP127In vitro, surface [6]
YesEhCP226 In vitro, membrane-associated[7]
YesEhCP11235.5In vitro (zymogram), surface[8]
YesEhCP530 In vitro (zymogram), and it is essential ex vivo for the cleavage of the collagen network, surface[9, 10]
Yes56 In vitro, secreted[11]
No72In vitro (zymogram), crude extracts and EDG[12]
Yes27–29In vitro [13]
 LamininYesEhCP426 In vitro, secreted and nuclear[14]
Yes56 In vitro, secreted[11]
Yes27–29In vitro [13]
 FibronectinYesEhCP11235.5In vitro (zymogram), surface[8]
Yes56 In vitro, secreted[11]
Yes27–29In vitro [13]
 GelatinNo110, 68, 56, and 22Induced by collagen, conditioned medium[15]


 IgAYesEhCP426In vitro, secreted and nuclear[14]
Yes70In vitro [16]
 IgGYesEhCP530In vitro, surface[9]
YesEhCP426In vitro, secreted and nuclear[14]
YesEhCP127In vitro, surface[17]
Yes56 In vitro, secreted[11]


 C3YesEhCP426In vitro, secreted and nuclear[14]
YesEhCP127In vitro, surface[17]
Yes56 In vitro [18]
 C3a and C5aYes56 In vitro [19]


 proIL-18YesEhCP426In vitro, secreted and nuclear[14]
YesEhCP530In vitro, surface[20]
YesEhCP127In vitro, surface[17]
 proIL-1βYesEhCP127In vitro, surface[21, 22]
EhCP226In vitro, membrane-associated[21, 22]

Iron-containing proteins

 HemoglobinYesEhCP11235.5In vitro (zymogram), surface[8]
YesEhCP530In vitro (zymogram), surface[9]
Yes41, 27In vitro, intracellular[23]
No32, 40In vitro, total extract[24]
Yes22In vitro [25]
Yes16In vitro [26]
No116, 82, 28, and 21Human, porcine, and bovine Hb in vitro (zymogram)[27]
 TransferrinNo130, 43, 20, and 6 Total extract
in vitro (zymogram)
No130, 70, 50, 35, and 30 Conditioned medium
in vitro (zymogram)
 LactoferrinNo250, 100, 40, and 22 Total extract
in vitro (zymogram)
 FerritinNo100, 75, and 50 Total extract
in vitro (zymogram)

Other proteins or tissues

 MucinYesEhCP530In vitro (zymogram), although ex vivo is not needed to cross the mucus, surface[9, 31]
 ProteoglycanYesEhCP226In vitro, membrane-associated[7]
 VillinYesEhCP127In vitro, surface[14]
YesEhCP426Iin vitro, secreted and nuclear[14]
 FibrinogenYesEhCP530In vitro (zymogram), surface[9]
 BSAYesEhCP530In vitro (zymogram), surface[9]

EDG: electron-dense granules.