title: Invasion of erythrocytes by Plasmodium falciparum malaria parasites: evidence for receptor heterogeneity and two receptors.
abstract: Plasmodium falciparum malaria parasites with different capabilities of invading sialic acid-deficient erythrocytes were identified. Thai-2 parasites cultured in Tn erythrocytes invaded neuraminidase-treated and Tn erythrocytes twice as efficiently as Thai-2 parasites cultured in normal erythrocytes and seven to ten times more efficiently than a cloned line of Camp parasites cultured in normal erythrocytes. All three parasite lines required sialic acid for optimal invasion, but Thai-2 parasites cultured in Tn erythrocytes invaded neuraminidase-treated erythrocytes with 45% efficiency whereas Camp parasites invaded neuraminidase-treated erythrocytes with less than 10% efficiency. P falciparum malaria parasites probably possess two receptors: one that binds to a sialic acid-dependent ligand and another that binds to a sialic acid-independent ligand. Parasites may differ in the quantity or affinity of their receptors for the sialic acid-independent ligand.
mesh_terms: D001665:Binding Sites; D004910:Erythrocyte Membrane / Q000502:physiology*; D004912:Erythrocytes / Q000378:metabolism / Q000469:parasitology*; D006801:Humans; D009439:Neuraminidase / Q000378:metabolism; D010963:Plasmodium falciparum / Q000472:pathogenicity*; D012794:Sialic Acids / Q000097:blood; D014357:Trypsin / Q000378:metabolism
chemical_list: D012794:Sialic Acids; D009439:Neuraminidase; D014357:Trypsin