title: Sialylation of lactosyl lipids in membrane microdomains by T. cruzi trans-sialidase.
abstract: A synthetic perfluoroalkyl-tagged lactosyl glycolipid has been shown to form lipid microdomains in fluid phospholipid bilayers. When embedded in the membranes of phospholipid vesicles, this glycolipid was trans-sialylated by soluble T. cruzi trans-sialidase (TcTS) to give a perfluoroalkyl-tagged glycolipid that displayed the ganglioside GM3 epitope, with up to 35% trans-sialylation from fetuin after 18 h. Following sialylation, vesicles bearing this Neu5Ac(α2-3)Gal(β1-4)Glc sequence in their "glycocalyx" were recognised and agglomerated by the lectin M. amurensis leukoagglutinin. Monitoring TcTS-mediated trans-sialylation by HPLC over the first 6 h revealed that enzymatic transformation of bilayer-embedded substrate was much slower than that of a soluble lactosyl substrate. Furthermore, clustering of the lactose-capped glycolipid into "acceptor" microdomains did not increase the rate of sialic acid transfer from fetuin by soluble TcTS, instead producing slight inhibition.
authors.affiliation: Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK. sabine.flitsch@manchester.ac.uk S.Webb@manchester.ac.uk.
authors.forename: Gavin T
authors.initials: GT
authors.lastname: Noble
authors.forename: Faye L
authors.initials: FL
authors.lastname: Craven
authors.forename: Maria Dolores
authors.initials: MD
authors.lastname: Segarra-Maset
authors.forename: Juana Elizabeth Reyes
authors.initials: JE
authors.lastname: Martínez
authors.forename: Robert
authors.initials: R
authors.lastname: Šardzík
authors.forename: Sabine L
authors.initials: SL
authors.lastname: Flitsch
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Webb
mesh_terms: D001665:Binding Sites; D006023:Glycoproteins / Q000378:metabolism*; D007785:Lactose / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D021962:Membrane Microdomains / Q000737:chemistry* / Q000201:enzymology; D008958:Models, Molecular; D015394:Molecular Structure; D009439:Neuraminidase / Q000378:metabolism*; D012794:Sialic Acids / Q000737:chemistry*; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D006023:Glycoproteins; D008055:Lipids; D012794:Sialic Acids; C069715:trans-sialidase; D009439:Neuraminidase; D007785:Lactose