This paper describes a global investigation of the components of Fasciola h
epatica excretory-secretory (ES) products by a proteomic approach. Despite
the absence of a F hepatica genome sequencing project we have shown that it
was possible to identify 29 of the 60 prominent proteins found using two-d
imensional gel electrophoresis. As well as cathepsin L proteases, a number
of enzymes implicated in parasite protection from the host immune system we
re also found to be present in relatively large abundance. These included s
uperoxide dismutase, thioredoxin peroxidase, glutathione S-transferases and
fatty acid binding proteins, all of which may play a part in the detoxific
ation of reactive oxygen intermediates. Interestingly, ovine superoxide dis
mutase was the only protein from the host identified on the gel. We suggest
that the relative abundance and protective nature of the components of the
ES products of this organism play an important role in its survival within
the host. The precise identification, to individual NCBI database entries,
of a number of glutathione S-transferases and cathepsin Ls from F hepatica
, by peptide mass fingerprinting, was hampered by multidatabase submissions
of the two protein superfamilies from this organism.