Cysteine conjugate β-lyase activity in three species of parasitic helminth

Abstract

Living organisms employ a variety of metabolic pathways when detoxifying xenobiotic compounds, including the formation of cysteine S-conjugates via glutathione conjugation. However, cysteine conjugate β-lyase (CCBL) catalysed β-cleavage, of certain cysteine conjugates, is known to cause cytotoxicity. This study represents the first investigation into the expression of CCBL and other associated enzymes in helminth species. A survey of the three major groups of parasitic helminths [cestodes ( Moniezia expansa), digeneans ( Fasciola hepatica) and nematodes ( Necator americanus, Heligmosomoides polygyrus)] has been made. The presence of CCBL enzymes within Moniezia expansa, Necator americanus and Heligmosomoides polygyrus has been established. Each species was screened for γ-glutamyl transpeptidase activity and transaminase activity towards l-aspartate, l-alanine, l-albizziin and l-phenylalanine. Aspartate and alanine aminotransferase activity were detected in all four species tested. γ-Glutamyl transpeptidase activity was only detected in Moniezia expansa and Necator americanus.