Plasmodium chabaudi p68 Serine Protease Activity Required for Merozoite Entry into Mouse Erythrocytes

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 89; no. 20; pp. 9647 - 9651
• Main Authors: Breton, Catherine Braun, Blisnick, Thierry, Jouin, Helene, Barale, Jean Christophe, Rabilloud, Thierry, Langsley, Gordon, Luis H. Pereira da Silva
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 15.10.1992; National Acad Sciences; National Academy of Sciences
• Subjects: activity; Animals; Anion Exchange Protein 1, Erythrocyte; Anion Exchange Protein 1, Erythrocyte - metabolism; Chemical suspensions; Enzyme substrates; Enzymes; Erythrocyte invasion; Erythrocyte Membrane; Erythrocyte Membrane - metabolism; Erythrocytes; Erythrocytes - parasitology; Gels; Life Sciences; Malaria; Merozoites; Mice; Microbiology and Parasitology; Molecular Weight; Parasites; Parasitology; Plasmodium chabaudi; Plasmodium chabaudi - enzymology; Protease Inhibitors; Protease Inhibitors - pharmacology; Schizonts; Serine Endopeptidases; Serine Endopeptidases - chemistry; Serine Endopeptidases - metabolism; serine proteinase; Substrate Specificity
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.89.20.9647

To define the role of malaria parasite enzymes during the process of erythrocyte invasion, we have developed an in vitro serum-free invasion assay of mouse erythrocytes by purified Plasmodium chabaudi merozoites. The sensitivity of a merozoite-specific serine protease (p68) to various inhibitors and the effect of these inhibitors on invasion indicate a crucial role for p68. The substrate specificity of the purified enzyme has been partially defined using fluorogenic peptides. Consistent with this, in vitro incubation of mouse erythrocytes with the merozoite enzyme led to the cleavage of band 3 protein. The possible implication of erythrocyte band 3 truncation for the successful entry of the merozoite into the erythrocyte is discussed.