S. Abdel-rahman et al., Biochemical characterization and localization of Fasciola hepatica 26-28 kDa diagnostic coproantigen, PARASITE IM, 21(6), 1999, pp. 279-286
We have previously reported the usefulness of a 26-28 kDa coproantigen of F
asciola hepatica for diagnosis of infection, In this study, the 26-28 kDa c
oproantigen was biochemically characterized with the aid of monoclonal anti
bodies (MoAb) in an effort to better understand the biology of the antigen.
Differential staining of chromatographically-purified 26-28 kDa coproantig
en on SDS-PAGE, under reducing and nan-reducing conditions indicated that t
he coproantigen was a monomeric, highly glycosylated glycoprotein. Alkaline
treatment of the purified coproantigen resulted in an 8 kDa protein core w
hich still contained the epitope recognized by the MoAb. No protease activi
ty was associated with the 26-28 kDa coproantigen. The coproantigen could b
e cleaved by trypsin without altering the reactive epitope recognized by th
e MoAb, but was resistant to pepsin digestion. Further, the coproantigen wa
s stable under several different storage conditions. Indirect immunofluores
cence on tissue sections of adult flukes indicated that the coproantigen wa
s present in gut cells and tegument, Taken together these results confirm t
he stability of the 26-28 kDa coproantigen and its usefulness in diagnostic
tests for F. hepatica infections.