Trypanosoma cruzi Peptidases: An Overview

Peptidases are a group of enzymes which have a catalytic function that is to hydrolyze peptide bonds of pro- teins. The enzymes that hydrolyze peptide bonds at the amino- or carboxy- terminus are classified as exopeptidases, and those that cleave peptide bonds inside the polypeptide are endopeptidases. Endopeptidases, such as cysteine-, metalo-, ser- ine- and threonine peptidases as well as some exopeptidases, have been characterized in Trypanosoma cruzi. Understand- ing the pathogenesis of T. cruzi requires the identification of functional properties of those peptidases, as they are implied in virulence, are important for host-parasite interactions and are critical for successful survival in their hosts. Here we examine the main T. cruzi peptidases, focusing on their biological roles, especially concerning the parasite-mammalian host relations.