Isolation and biochemical characterisation of a glutathione S-transferase from Echinococcus granulosus protoscoleces.

A protein fraction migrating as a M(r) 24 kDa band on SDS-PAGE was isolated by affinity chromatography on glutathione-agarose from a soluble extract of E. granulosus proto-scoleces from sheep(UK). This fraction had glutathione S-transferase activity of 0.4 mumol min-1 mg-1 when measured using a standard synthetic substrate and its determined N-terminal amino acid sequence most closely resembled Mu class glutathione S-transferases. In addition, protoscoleces from the distinct sheep and horse E. granulosus strains showed a different pattern of glutathione-binding proteins: the M(r) 24 kDa species was obtained in both cases whereas an additional band of slightly faster electrophoretic mobility was isolated from horse(UK) protoscoleces.