MUCIN-LIKE GLYCOPROTEINS LINKED TO the MEMBRANE BY GLYCOSYLPHOSPHATIDYLINOSITOL ANCHOR ARE the MAJOR ACCEPTORS of SIALIC-ACID in A REACTION CATALYZED BY TRANS-SIALIDASE in METACYCLIC FORMS of TRYPANOSOMA-CRUZI

MUCIN-LIKE GLYCOPROTEINS LINKED TO the MEMBRANE BY GLYCOSYLPHOSPHATIDYLINOSITOL ANCHOR ARE the MAJOR ACCEPTORS of SIALIC-ACID in A REACTION CATALYZED BY TRANS-SIALIDASE in METACYCLIC FORMS of TRYPANOSOMA-CRUZI

Author Schenkman, S. Google Scholar
Ferguson, MAJ Google Scholar
Heise, N. Google Scholar
Dealmeida, MLC Google Scholar
Mortara, R. A. Google Scholar
Yoshida, N. Google Scholar
Institution UNIV DUNDEE
Universidade Federal de São Paulo (UNIFESP)
Abstract We have previously shown that 35- and 50-kDa glycoconjugates of cultured metacyclic trypomastigotes participate in the attachment of parasites to mammalian cells. Here we show that when metacyclic trypomastigotes are incubated with [H-3]sialyllactose, most of the sialic acid is transferred to these 35/50-kDa molecules in a reaction catalyzed by a parasite transsialidase. the sialic acid is incorporated in oligosaccharides of about 10 glucose units in size that are released from the glycoconjugate by mild alkaline hydrolysis. Compositional analysis reveals that the 35/50-kDa molecules are highly glycosylated proteins rich in threonine, galactose, N-acetyl-glucosamine and sialic acid. These glycoproteins can be labeled in vivo with [H-3]palmitate, and the labeled fatty acid is released by glycosylphosphatidylinositol specific phospholipases C. This result, associated with the fact that they contain mannose, ethanolamine, myo-inositol, and lipid, indicate that these glycoproteins are anchored to the membrane by glycosylphosphatidylinositol. During cell invasion, these molecules appear to be capped and locally released by the parasite.
Keywords TRYPANOSOMA-CRUZI
SIALIC ACID
TRANS-SIALIDASE
CELL INVASION
GLYCOSYLPHOSPHATIDYLINOSITOL
Language English
Date 1993-06-01
Published in Molecular and Biochemical Parasitology. Amsterdam: Elsevier B.V., v. 59, n. 2, p. 293-303, 1993.
ISSN 0166-6851 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 293-303
Origin http://dx.doi.org/10.1016/0166-6851(93)90227-O
Access rights Closed access
Type Article
Web of Science ID WOS:A1993LE84900012
URI http://repositorio.unifesp.br/handle/11600/25331

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