J. Khalife et al., MOLECULAR CHARACTERIZATION OF 2 SCHISTOSOMA-MANSONI PROTEINS SHARING COMMON MOTIFS WITH THE VIF PROTEIN OF HIV-1, Parasitology, 108, 1994, pp. 533-542
We have previously described a rat mAb directed against a peptide deri
ved from the vif protein of HIV-1 that recognized two Schistosoma mans
oni (Sm) antigens with a major band at 65 kDa. Epitope mapping of this
mAb using overlapping hexapeptides derived from the vif peptide revea
led that the motif recognized was PLPSVT. The screening of a Sm cDNA l
ibrary led to the identification of two clones, Sm70 and Sm65. The two
deduced protein sequences did not share any common structural feature
s apart from the epitope recognized by the mAb (see below), and did no
t show significant identity to sequences present in the data bases. Ho
wever, the N terminus of the deduced sequence of the Sm70 protein exhi
bits a consensus sequence known to be an ATP/GTP binding site. Further
more, the C terminus of the deduced Sm65 protein sequence was found to
contain a conserved hexapeptide with a consensus sequence LPETGE repo
rted 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 wi
th both proteins. However, only Sm65 was recognized by sera from HIV-1
-seropositive individuals, whereas both proteins were recognized by S.
mansoni-infected patients.