The expression of a Plasmodium falciparum 41 kDa blood stage antigen (p41) was followed by examining both protein level and aldolase activity in synchronized cultures. The protein and enzymatic levels were low in erythrocytes containing ring forms, and increased markedly with the appearance of trophozoites and young schizonts. The subcellular localization of p41 aldolase was determined using immunoelectron microscopy with rabbit anti-p41 and anti-recombinant p41 antisera. P41 was localized within the cytoplasm of P. falciparum extracellular merozoites, trophozoites and schizonts.
