Molecular characterization of two Schistosoma mansoni proteins sharing common motifs with the vif protein of HIV-1.
We have previously described a rat mAb directed against a peptide derived from the vif protein of HIV-1 that recognized two Schistosoma mansoni (Sm) antigens with a major band at 65 kDa. Epitope mapping of this mAb using overlapping hexapeptides derived from the vif peptide revealed that the motif recognized was PLPSVT. The screening of a Sm cDNA library led to the identification of two clones, Sm70 and Sm65. The two deduced protein sequences did not share any common structural features apart from the epitope recognized by the mAb (see below), and did not show significant identity to sequences present in the data bases. However, the N terminus of the deduced sequence of the Sm70 protein exhibits a consensus sequence known to be an ATP/GTP binding site. Furthermore, the C terminus of the deduced Sm65 protein sequence was found to contain a conserved hexapeptide with a consensus sequence LPETGE reported to be an important motif of the surface proteins of gram-positive cocci. Both proteins exhibit a peptide sequence (PLRSVT for Sm70 and PVGSVT for Sm65) similar to the epitope recognized by the mAb anti-vif. Western blotting experiments showed that the mAb anti-vif reacted with both proteins. However, only Sm65 was recognized by sera from HIV-1-seropositive individuals, whereas both proteins were recognized by S. mansoni-infected patients.
Khalife
J
J
Centre d'immunologie et de Biologie Parasitaire, INSERM U 167-CNRS 624, Institut Pasteur, Lille, France.
Pierce
R J
RJ
Godin
C
C
Capron
A
A
D000595:Amino Acid Sequence; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth / Q000235:genetics; D001483:Base Sequence; D006224:Cricetinae; D018076:DNA, Complementary / Q000235:genetics; D016346:Gene Products, vif / Q000235:genetics* / Q000276:immunology; D015483:HIV Antibodies / Q000097:blood; D015488:HIV Antigens / Q000235:genetics; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology; D015801:Helminth Proteins / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008969:Molecular Sequence Data; D051381:Rats; D012550:Schistosoma mansoni / Q000235:genetics* / Q000276:immunology; D012555:Schistosomiasis mansoni / Q000276:immunology; D017386:Sequence Homology, Amino Acid; D054320:vif Gene Products, Human Immunodeficiency Virus
D000909:Antibodies, Helminth; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth; D018076:DNA, Complementary; D016346:Gene Products, vif; D015483:HIV Antibodies; D015488:HIV Antigens; D015801:Helminth Proteins; D054320:vif Gene Products, Human Immunodeficiency Virus