The surface trans-sialidase family of Trypanosoma cruzi.
Trypanosomes cannot synthesize sialic acids. Infectious stages of the life cycle of the human pathogen Trypanosoma cruzi express a cell-surface glycolipid-anchored trans-sialidase, which can transfer sialic acid between glyco-conjugates. Sialic acid is transferred from host cell-surface and serum sialylglycoproteins to trypanosome cell-surface glycoconjugates. The transfer reaction is specific for donors with terminal alpha-2,3-linked sialic acid, and terminal beta-1,4-linked galactose is the preferred acceptor. In the absence of an acceptor, the enzyme acts as a hydrolase, but cleavage is less efficient than transfer. Trans-sialidase activity is attributable to a few members of a large family of T. cruzi surface glycoproteins, many of which are simultaneously expressed. The functions of the trans-sialidase surface glycoprotein family are unknown but may be important for adhesion, invasion, virulence, or pathogenicity. A trans-sialidase is also expressed in the procyclic forms of Trypanosoma brucei.
Cross
G A
GA
Labortory of Molecular Parasitology, Rockefeller University, New York, NY 10021.
Takle
G B
GB
D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D012799:Sialyltransferases / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000201:enzymology*
D008565:Membrane Proteins; D012799:Sialyltransferases