title: A comparison of knobby (K+) and knobless (K-) parasites from two strains of Plasmodium falciparum.
abstract: Erythrocytes infected with Plasmodium falciparum develop knob-like protrusions on their membranes. Knobby (K+) parasites of the FCR-3 (Gambian) strain have been shown to possess a histidine-labelled protein of apparent molecular weight 80 000 which is absent from knobless (K-) variants of the same strain. Here we report similar findings with K+ and K- parasites of another strain, the Malayan Camp strain, and also with cloned K+ and K- parasites of the FCR-3 strain. A histidine-labelled protein unique to the two K+ parasites was identified as a broad band with an apparent molecular weight of 89 000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The presence of this protein in both K+ Malayan Camp parasites and K+ FCR-3 (Gambian) parasites and its absence from K- parasites of both strains is consistent with this protein being a major component of knobs.
mesh_terms: D000818:Animals; D001029:Aotus trivirgatus; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004910:Erythrocyte Membrane / Q000469:parasitology; D004912:Erythrocytes / Q000469:parasitology; D008970:Molecular Weight; D010963:Plasmodium falciparum / Q000235:genetics*; D011506:Proteins / Q000235:genetics*; D012967:Sodium Dodecyl Sulfate
chemical_list: D011506:Proteins; D012967:Sodium Dodecyl Sulfate