Has protein tyrosine phosphatase activity. H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Activated in a reduced environment which promotes the reduction of the disulfide bond between the regulatory Cys-52 and the catalytic Cys-107 residues (By similarity). Inhibited by sodium orthovanadate (PubMed:16151248). Optimum pH is 7.5-8. In epimastigotes, localizes close to flagellar pocket, cytostome and to reservosomes. Reservosomes are prelysosomal-like acidic organelles found at the cell posterior end which contain the protease cruzipain and ingested proteins and lipids. In amastigotes and trypomastigotes partially co-localizes with concavalin A, a marker of the endocytic pathway. Expressed at the amastigote life cycle stage (at protein level). Expressed at the epimastigote, amastigote and trypomastigote life cycle stages. Belongs to the protein-tyrosine phosphatase family.