Cysteine proteases of parasitic helminths

Abstract

Cysteine protease and/or thiol peptidase/sulphydryl peptidase/cysteinyl peptidaseinvariably contain cysteine at their active site and hence collectively termedas cathepsins. This proteolytic enzyme, secreted and/or regurgitated/excreted bythe in situ invasive forms of metazoan parasites of men and domestic livestock, often involve in the host tissue penetration, digestion of nutrients, and theiravailability to the parasite for its growth and development, evasion of hostdefense, and in of late documented their significant role in detection of in situparasites at an early developmental stage(s) [Immunodiagnosis] beside animportant entity to develop immunoprotection strategies against the livestockdiseases, so much so, to contain and curb the colossal recurring losses, incidentalto widely prevalent parasitic disease, to the fast developing livestock productsbased food industry in the developing world. Herein, the authors discuss thehistorical background, molecular structure, and classification of cathepsinproteases and update advancements in exploiting the enzyme for early diagnosisand planning immunoprotection strategies against metazoan parasitic diseaseswith special reference to tropical fasciolosis.