Purification and properties of recombinant Plasmodium falciparum S-adenosyl-L-homocysteine hydrolase

Recombinant S-adenosyl-L-homocysteine (SAH) hydrolase of the malaria parasi te Plasmodium falciparum was expressed in Escherichia coli, purified to hom ogeneity and characterized. Comparison of the malaria parasite SAH hydrolas e with that derived from the human gene indicated marked differences in k(c at) values. The values of both forward and reverse reactions of P, falcipar um SAH hydrolase are more than 21-fold smaller than those of the human enzy me. K-m values of the parasite and human SAH enzymes are 1.2 and 7.8 muM, r espectively. On the other hand, IC50 values of neplanocin A, a strong inhib itor of SAH hydrolase and a growth inhibitor of P, falciparum, are 101 nM f or the parasite enzyme and 47 nM for human enzyme. P, falciparum SAH hydrol ase has been thought to be a target for a chemotherapeutic agent against ma laria. This study may make it possible to develop a specific inhibitor for the parasite SAH hydrolase.