title: Assessing the cluster glycoside effect during the binding of concanavalin A to mannosylated artificial lipid rafts.
abstract: Mannosyl glycolipids with perfluoroalkyl membrane anchors have been synthesised. When inserted into vesicles, these mannosyl lipids either dispersed evenly over the surface or, in the presence of cholesterol, phase-separated into artificial lipid rafts. At 1% mol/mol, the affinity of dispersed mannosyl lipids for Con A was 3-fold weaker than in solution, perhaps reflecting steric blocking by the surface. However increasing membrane loading 5-fold increased Con A affinity by up to 75% and indicated weak intramembrane chelation of Con A. Despite this observation, concentrating the mannosyl lipids into artificial lipid rafts did not significantly improve affinity for Con A. This lack of a cluster glycoside effect was ascribed to lipid congestion inhibiting intra-raft chelation of Con A, and implies that glycolipids located in lipid rafts may not necessarily be preorganised for multivalent binding.
authors.affiliation: Manchester Interdisciplinary Biocentre, The University of Manchester and School of Chemistry, 131 Princess Street, Manchester, M1 7DN, UK.
authors.forename: Gavin T
authors.initials: GT
authors.lastname: Noble
authors.forename: Sabine L
authors.initials: SL
authors.lastname: Flitsch
authors.forename: Kwan Ping
authors.initials: KP
authors.lastname: Liem
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Webb
mesh_terms: D002784:Cholesterol; D003208:Concanavalin A / Q000378:metabolism*; D006027:Glycosides / Q000737:chemistry*; D006031:Glycosylation; D008358:Mannose / Q000737:chemistry; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism*; D008567:Membranes, Artificial; D008954:Models, Biological; D011485:Protein Binding
chemical_list: D006027:Glycosides; D008567:Membranes, Artificial; D003208:Concanavalin A; D002784:Cholesterol; D008358:Mannose