During the asexual blood stage, catalyzes the initial cleavage of native host hemoglobin (Hb) resulting in Hb denaturation; specifically cleaves between Phe-33 and Leu-34 of Hb alpha-chain. Digestion of host Hb is an essential step which provides the parasite with amino acids for protein synthesis, and regulates osmolarity. Hydrolysis of the 33-Phe-|-Leu-34 bond in the alpha-chain of hemoglobin, leading to denaturation of molecule. Inhibited by KNI derived compounds KNI-10333 and to a lesser extent KNI-10743. At the beginning of the asexual blood stage, the transmembrane zymogen is transported to the cytostome, an endocytic structure spanning the parasite cell membrane and the parasitophorous vacuole membrane where host proteins such as hemoglobin are endocytosed. Following endocytosis, localizes to the cytostome vacuole membrane to be then delivered to the digestive (or food) vacuole where it is cleaved into the soluble and active enzyme. In trophozoites, localizes to the digestive vacuole, an acidic vacuole where host hemoglobin is digested. Expressed during the asexual blood stage including in trophozoites (at protein level). Not N-glycosylated. Proteolytically cleaved into the soluble active mature form in the digestive vacuole by cysteine protease falcipains; the process begins at the early ring stage (PubMed:14709539). Proteolysis requires an acidic environment (By similarity). No growth defect (PubMed:15513918). However, slight decrease in proliferation and slight increase in doubling time during the asexual blood stage in an amino acid-limited medium (PubMed:15513918). Belongs to the peptidase A1 family.