Comparison of efficacies of cysteine protease inhibitors against five strains of Plasmodium falciparum

Falcipain-2, a cysteine protease and essential hemoglobinase of Plasmodium falciparum, is a potential antimalarial drug target. We compared the falcip ain-2 sequences and sensitivities to cysteine protease inhibitors of five p arasite strains that differ markedly in sensitivity to established antimala rial drugs, The sequence of falcipain-2 was highly conserved, and the sensi tivities of all of the strains to falcipain-2 inhibitors were very similar, Thus, cross-resistance between cysteine protease inhibitors and other anti malarial agents is not expected in parasites that are now circulating and f alcipain-2 remains a promising chemotherapeutic target.