G. Abuin et al., TURNOVER AND SHEDDING OF THE TC-85 SURFACE GLYCOPROTEIN OF TRYPANOSOMA-CRUZI TRYPOMASTIGOTES, Brazilian journal of medical and biological research, 29(3), 1996, pp. 335-341
Tc-85 is an 85-kDa surface glycoprotein specific for the trypomastigot
e stage of Trypanosoma cruzi which has been implicated in the invasion
of host cells by the parasite, Tc-85 has a half-life of 3.5-4 h and i
s synthesized as a 95-kDa precursor. Processing of the 95-kDa precurso
r is inhibited by N-p-tosyl-L-lysine chloromethyl ketone, p-chloromerc
uriphenylsulfonic acid, iodoacetamide or N-ethyl-maleimide, but not by
aprotinin, antipain or phenylmethylsulfonil fluoride. Tc-85, but not
the precursor, is rapidly shed into the medium, allowing a correlation
between the decrease of Tc-85 in trypomastigotes and its increase in
the culture medium. The shedding of Tc-85 was inhibited 50% by 1 mu M
tunicamycin, but not by 10 mu M swainsonine or 10 mu M 1-deoxynojirimy
cin under the experimental conditions employed. This suggests that N-l
inked oligosaccharides are important for the shedding phenomenon, alth
ough it appears that they do not have to be fully processed for sheddi
ng to occur.