Epitope map and processing scheme for the 195,000-dalton surface glycoprotein of Plasmodium falciparum merozoites deduced from cloned overlapping segments of the gene.
DNA fragments from human malaria parasites were cloned into lambda gt11 to produce a genomic DNA expression library. A pool of monoclonal antibodies (mAbs) recognizing three domains of the 195-kDa major merozoite surface glycoprotein (gp195) reacted with seven clones expressing malaria antigens. mAbs recognizing the 83-kDa product of gp195 reacted with the clones, but mAbs recognizing a glycosylated 45-kDa and a nonglycosylated 45-kDa domain did not. Restriction enzyme mapping revealed that the clones contained overlapping segments encoding about 70% of the gene beginning at the 5' end and ending at an EcoRI restriction enzyme site 3.3 kilobase pairs downstream. The mAbs recognizing the 83-kDa domain reacted differently with the clones, allowing the mapping of three epitopes, one of which was repetitive. Affinity-purified antibodies were selected from immune monkey serum with recombinant expression proteins adsorbed to nitrocellulose filters. When used to probe electrophoretic immunoblots of parasite extracts, these antigen-selected antibodies reacted with specific sets of processed products of gp195, including those associated with the 83- and the nonglycosylated 45-kDa domains. This information, combined with the mAb epitope map, allowed a tentative scheme for processing gp195 from the Camp strain to be proposed.
J A
JA
Lyon
R H
RH
Geller
J D
JD
Haynes
J D
JD
Chulay
J L
JL
Weber
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000953:Antigens, Protozoan / Q000235:genetics*; D003001:Cloning, Molecular; D000939:Epitopes / Q000032:analysis / Q000235:genetics*; D006023:Glycoproteins / Q000235:genetics* / Q000276:immunology; D010963:Plasmodium falciparum / Q000235:genetics* / Q000276:immunology
D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan; D000939:Epitopes; D006023:Glycoproteins