Expression of an enzymatically active parasite molecule in Escherichia coli: Schistosoma japonicum glutathione S-transferase.

The NH2-terminal amino acid sequence of the Mr 26 000 glutathione S-transferase (EC 2.5.1.18) of Schistosoma japonicum (Sj26) has been deduced by RNA and protein sequence analysis. Using this information, a bacterial plasmid has been constructed that directs the synthesis of the entire Sj26 molecule in Escherichia coli. Recombinant Sj26 exhibits glutathione S-transferase activity and can be readily purified from bacteria in a one-step procedure under non-denaturing conditions. The availability of recombinant Sj26 in essentially unlimited quantities will aid its assessment as a candidate vaccine molecule in schistosomiasis and could eventually lead to the rational design of a drug targetted on schistosome glutathione S-transferases.