title: Does a histidine-rich protein from Plasmodium lophurae have a function in merozoite penetration?
abstract: Autoradiography was used to localize the distribution of L-[3H]histidine incorporated in vitro by developing  segmenters of Plasmodium lophurae. Under conditions used for the visualization of high specific activity loci, radioactivity appeared associated mainly with the histidine-rich protein of cytoplasmic granules as well as with rhoptries and micronemes of merozoites. The isolated histidine-rich protein caused agglutination of erythrocytes and increased their osmotic fragility. Based on the observed evidence suggesting the presence of this histidine-rich protein in the polar organelles of merozoites and its reactivity with erythrocyte membranes, the hypothesis that such a protein may have a function in the penetration of merozoites is proposed.
mesh_terms: D000371:Agglutination; D000818:Animals; D003594:Cytoplasmic Granules / Q000378:metabolism / Q000648:ultrastructure; D004372:Ducks; D004912:Erythrocytes / Q000276:immunology / Q000648:ultrastructure; D006639:Histidine / Q000378:metabolism*; D009996:Osmotic Fragility; D010961:Plasmodium / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D014176:Protein Biosynthesis; D011506:Proteins / Q000276:immunology / Q000502:physiology*
chemical_list: D011506:Proteins; D006639:Histidine