Abstract
The malaria parasite Plasmodium falciparum uses host erythrocyte hemoglobin as a major nutrient source. We report the purification of P. falciparum digestive vacuoles and characterization of the degradative process therein. Vacuoles were isolated by a combination of differential centrifugation and density gradient separation. The pure vacuoles were capable of degrading hemoglobin to small fragments with a pH optimum of 5-5.5. Proteolysis in the vacuoles appears to be an ordered process, requiring an aspartic protease to clip intact hemoglobin before other proteolytic activities can function efficiently. The vacuoles do not contain other hydrolases commonly found in lysosomes and therefore appear to be unique proteolytic organelles designed specifically to degrade hemoglobin.
| Original language | English |
|---|---|
| Pages (from-to) | 2931-2935 |
| Number of pages | 5 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 87 |
| Issue number | 8 |
| State | Published - Apr 1990 |
Keywords
- Aspartic protease
- Hemozoin
- Lysosomes
- Vacuoles