   3.4.11.9 | physiological function |
peptide recycling, the process by which cellular proteins are broken down to single amino acid residues, is critical to parasite survival. In blood-stage malaria parasites, two major processes are responsible for peptide turnover: proteasomal (within the cytosol) and vacuolar (in the specialized digestive food vacuole). The vacuolar pathway is responsible for the digestion of 60-80% of host cell hemoglobin, which is imported into the digestive vacuole and degraded into free amino acids. This process is absolutely necessary for parasite growth and development. The final step of peptide turnover, the removal of N-terminal amino acids from short polypeptide chains, is catalyzed by a panel of aminopeptidases, which work in concert according to different substrate specificities, to complete protein digestion. During the blood stage, the parasites utilise a proteolytic cascade to digest host hemoglobin, which produces free amino acids absolutely necessary for parasite growth and reproduction. The enzymes required for hemoglobin digestion are therefore attractive therapeutic targets. The final step of the cascade is catalyzed by several metalloaminopeptidases, including aminopeptidase P (APP) |
752716 |
