MALDI mass sequencing and characterization of filarialglutathione-S-transferase

Glutathione-S-transferase has been detected in the somatic extract and excretory–secretory products of different life stages of Setaria cervi, a bovine filarial parasite. The enzyme was subjected to MALDI-TOF followed by mass spectrometry and the nearest match found was Pleuronectes platessa GST. Molecular mass of the purified enzyme was≈26 kDa as determined by SDS–PAGE and MALDI-TOF. Setaria cervi GST exhibited high activity towards 1-chloro-2,4-dinitrobenzene and ethacrynic acid. Kinetic analysis with respect to 1-chloro-2,4-dinitrobenzene and glutathione as substrate revealed a Km of 2.22 mM and 0.61 mM, respectively. The activity was inhibited significantly by Cibacron blue and α-tocopherol.