title: Exploiting a (13)C-labelled heparin analogue for in situ solid-state NMR investigations of peptide-glycan interactions within amyloid fibrils.
abstract: Pathological amyloid deposits are mixtures of polypeptides and non-proteinaceous species including heparan sulfate proteoglycans and glycosaminoglycans (GAGs). We describe a procedure in which a (13)C-labelled N-acetyl derivative of the GAG heparin ([(13)C-CH(3)]NAcHep) serves as a useful probe for the analysis of GAG-protein interactions in amyloid using solid-state nuclear magnetic resonance (SSNMR) spectroscopy. NAcHep emulates heparin by enhancing aggregation and altering the fibril morphology of Abeta(1-40), one of the beta-amyloid polypeptides associated with Alzheimer's disease, and alpha-synuclein, the major protein component of Lewy bodies associated with Parkinson's disease. (13)C SSNMR spectra confirm the presence of [(13)C-CH(3)]NAcHep in Abeta(1-40) fibril deposits and detect dipolar couplings between the glycan and arginine R(5) at the Abeta(1-40) N-terminus, suggesting that the two species are intimately mixed at the molecular level. This procedure provides a foundation for further extensive investigations of polypeptide-glycan interactions within amyloid fibrils.
authors.affiliation: School of Biological Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom.
authors.forename: Jillian
authors.initials: J
authors.lastname: Madine
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Clayton
authors.forename: Edwin A
authors.initials: EA
authors.lastname: Yates
authors.forename: David A
authors.initials: DA
authors.lastname: Middleton
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism*; D000682:Amyloid / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D016229:Amyloid beta-Peptides / Q000378:metabolism; D002247:Carbon Isotopes; D006493:Heparin / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010300:Parkinson Disease / Q000378:metabolism*; D051844:alpha-Synuclein / Q000378:metabolism
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D002247:Carbon Isotopes; D051844:alpha-Synuclein; D006493:Heparin