Triose phosphate isomerase from the blood fluke Schistosoma mansoni: Biochemical characterisation of a potential drug and vaccine target

The glycolytic enzyme triose phosphate isomerase from Schistosoma mansoni is a potential target for drugs and vaccines. Molecular modelling of the enzyme predicted that a Ser-Ala-Asp motif which is believed to be a helminth-specific epitope is exposed. The enzyme is dimeric (as judged by gel filtration and cross-linking), resistant to proteolysis and highly stable to thermal denaturation (melting temperature of 82.0 °C). The steady-state kinetic parameters are high (K_m for dihydroxyacetone phosphate is 0.51 mM; K_m for glyceraldehyde 3-phosphate is 1.1 mM; k_cat for dihydroxyacetone phosphate is 7800 s⁻¹ and k_cat for glyceraldehyde 3-phosphate is 6.9 s⁻¹).