A 22 kDa protein associated with the Plasmodium falciparum merozoite surface protein-1 complex.
The Plasmodium falciparum merozoite surface protein-1 (MSP-1) is synthesized as a precursor of approximately 195 kDa and is processed to form a complex of polypeptides on the surface of free merozoites. As a result of a second processing event, the entire MSP-1 complex is shed from the surface, apart from a C-terminal fragment that remains anchored to the merozoite membrane. We have identified a 22 kDa protein (p22) on the surface of merozoites by cell surface radioiodination and indirect immunofluorescence assay on unfixed free merozoites. p22 is also a component of the shed MSP-1 complex where it is present in part as a 19 kDa form (p22(19)) as shown by immunochemical and peptide mapping analyses. The soluble complex contains MSP-1-derived polypeptides and p22 in approximately stoichiometrically equal amounts. N-terminal amino acid sequence analyses of p22/p22(19) showed that the protein is not derived from the MSP-1 precursor.
Division of Parasitology, National Institute for Medical Research, London, UK.
W H
WH
Stafford
B
B
Günder
A
A
Harris
H G
HG
Heidrich
A A
AA
Holder
M J
MJ
Blackman
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000378:metabolism; D046911:Macromolecular Substances; D020066:Merozoite Surface Protein 1; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010963:Plasmodium falciparum / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D000953:Antigens, Protozoan; D046911:Macromolecular Substances; D020066:Merozoite Surface Protein 1; D011498:Protein Precursors; D015800:Protozoan Proteins; C057273:antigen gp195, Plasmodium