Identification of a second catalytically active trans-sialidase in Trypanosoma brucei.

TitleIdentification of a second catalytically active trans-sialidase in Trypanosoma brucei.
Publication TypeJournal Article
Year of Publication2011
AuthorsNakatani F, Morita YS, Ashida H, Nagamune K, Maeda Y, Kinoshita T
JournalBiochem Biophys Res Commun
Date Published2011 Nov 18
KeywordsAmino Sugars, Catalysis, Cell Membrane, Cloning, Molecular, Glycoproteins, Glycosylphosphatidylinositols, Mutation, N-Acetylneuraminic Acid, Neuraminidase, Trypanosoma brucei brucei

The procyclic stage of Trypanosoma brucei is covered by glycosylphosphatidylinositol (GPI)-anchored surface proteins called procyclins. The procyclin GPI anchor contains a side chain of N-acetyllactosamine repeats terminated by sialic acids. Sialic acid modification is mediated by trans-sialidases expressed on the parasite's cell surface. Previous studies suggested the presence of more than one active trans-sialidases, but only one has so far been reported. Here we cloned and examined enzyme activities of four additional trans-sialidase homologs, and show that one of them, Tb927.8.7350, encodes another active trans-sialidase, designated as TbSA C2. In an in vitro assay, TbSA C2 utilized α2-3 sialyllactose as a donor, and produced an α2-3-sialylated product, suggesting that it is an α2-3 trans-sialidase. We suggest that TbSA C2 plays a role in the sialic acid modification of the trypanosome cell surface.

Alternate JournalBiochem. Biophys. Res. Commun.
PubMed ID22040733