IDENTIFICATION OF A DOMAIN OF TRYPANOSOMA-CRUZI METACYCLIC TRYPOMASTIGOTE SURFACE-MOLECULE GP82 REQUIRED FOR ATTACHMENT AND INVASION OF MAMMALIAN-CELLS
Fr. Santori et al., IDENTIFICATION OF A DOMAIN OF TRYPANOSOMA-CRUZI METACYCLIC TRYPOMASTIGOTE SURFACE-MOLECULE GP82 REQUIRED FOR ATTACHMENT AND INVASION OF MAMMALIAN-CELLS, Molecular and biochemical parasitology, 78(1-2), 1996, pp. 209-216
Recombinant proteins and synthetic peptides representing various seque
nces of gp82, a surface glycoprotein of Trypanosoma cruzi metacyclic t
rypomastigotes implicated in mammalian cell invasion, were used in thi
s study aiming at the identification of the domain(s) of this molecule
required for interaction with target cells. Invasion of cultured HeLa
cells by metacyclic trypomastigotes was inhibited by about 80% in the
presence of native gp82 or the corresponding recombinant construct J1
8. Inhibition by recombinant proteins J18a and J18b, containing respec
tively the N-terminal and the C-terminal portions of gp82, was on the
order of 30% and 65%. As compared to J18b (amino acids 224-516), the t
runcated gp82 fragments J18b1 (amino acids 303-516) and J18b2 (amino a
cids 357-516) displayed lower inhibitory effect (similar to 40% and si
milar to 15%, respectively). Compatible with these observations, we fo
und that the recombinant protein J18b, but not J18a or J18b2, binds to
HeLa cells in a dose-dependent and saturable fashion. Experiments wit
h ten overlapping synthetic peptides, representing the gp82 portion sp
anning amino acids 224-333, showed that peptides 4 (amino acids 254-27
3) and 8 (amino acids 294-313) have significant inhibitory activity on
HeLa cell invasion by metacyclic forms. All these results indicate th
at the portion of gp82 required for mammalian cell attachment and inva
sion is located in the central domain of the molecule.