title: Identification of two integral membrane proteins of Plasmodium falciparum.
abstract: We describe the isolation and cloning of two integral membrane protein antigens of Plasmodium falciparum. The antigens were isolated by Triton X-114 temperature-dependent phase separation, electrophoretically transferred to nitrocellulose, and used to affinity-purify monospecific human antibodies. These antibodies were used to isolate the corresponding cDNA clones from a phage lambda gt11-Amp3 cDNA expression library. Clone Ag512 corresponds to a Mr 55,000 merozoite rhoptry antigen, and clone Ag513 corresponds to a Mr 45,000 merozoite surface antigen. Both proteins can be biosynthetically labeled with [3H]glucosamine and [3H]myristic acid, suggesting that they may be anchored in membranes via a glycosylphosphatidylinositol moiety. Similarities in the C-terminal sequences of the Mr 45,000 merozoite surface antigen and the Trypanosoma brucei variant surface glycoproteins provides further evidence that this antigen has a glycosylphosphatidylinositol anchor.
authors.affiliation: Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
authors.forename: J A
authors.initials: JA
authors.lastname: Smythe
authors.forename: R L
authors.initials: RL
authors.lastname: Coppel
authors.forename: G V
authors.initials: GV
authors.lastname: Brown
authors.forename: R
authors.initials: R
authors.lastname: Ramasamy
authors.forename: D J
authors.initials: DJ
authors.lastname: Kemp
authors.forename: R F
authors.initials: RF
authors.lastname: Anders
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000302:isolation & purification; D000953:Antigens, Protozoan / Q000032:analysis* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004274:DNA, Recombinant / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D005455:Fluorescent Antibody Technique; D006801:Humans; D007118:Immunoassay; D007163:Immunosorbent Techniques; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010716:Phosphatidylinositols / Q000276:immunology; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins; D012689:Sequence Homology, Nucleic Acid
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D004274:DNA, Recombinant; C064417:GYMSSA antigen, Plasmodium falciparum; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010716:Phosphatidylinositols; D015800:Protozoan Proteins; D004247:DNA