Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. GST isoenzymes appear to play a central role in the parasite detoxification system. Other functions are also suspected including a role in increasing the solubility of haematin in the parasite gut. glutathione + RX = a halide anion + an S-substituted glutathione + H(+) Homodimer. There are at least two isoenzymes of GST in S.japonicum. Belongs to the GST superfamily. Mu family.