title: A new glycation product 'norpronyl-lysine,' and direct characterization of cross linking and other glycation adducts: NMR of model compounds and collagen.
abstract: NMR is ideal for characterizing non-enzymatic protein glycation, including AGEs (advanced glycation endproducts) underlying tissue pathologies in diabetes and ageing. Ribose, R5P (ribose-5-phosphate) and ADPR (ADP-ribose), could be significant and underinvestigated biological glycating agents especially in chronic inflammation. Using [U-13C]ribose we have identified a novel glycoxidation adduct, 5-deoxy-5-desmethylpronyl-lysine, 'norpronyl-lysine', as well as numerous free ketones, acids and amino group reaction products. Glycation by R5P and ADPR proceeds rapidly with R5P generating a brown precipitate with PLL (poly-L-lysine) within hours. ssNMR (solid-state NMR)13C-13C COSY identifies several crosslinking adducts such as the newly identified norpronyl-lysine, in situ, from the glycating reaction of13C5-ribose with collagen. The same adducts are also identifiable after reaction of collagen with R5P. We also demonstrate for the first time bio-amine (spermidine, N-acetyl lysine, PLL) catalysed ribose 2-epimerization to arabinose at physiological pH. This work raises the prospect of advancing understanding of the mechanisms and consequences of glycation in actual tissues, in vitro or even ex vivo, using NMR isotope-labelled glycating agents, without analyses requiring chemical or enzymatic degradations, or prior assumptions about glycation products.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
authors.forename: Peter T B
authors.initials: PT
authors.lastname: Bullock
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
authors.forename: David G
authors.initials: DG
authors.lastname: Reid
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
authors.forename: W
authors.initials: W
authors.lastname: Ying Chow
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
authors.forename: Wendy P W
authors.initials: WP
authors.lastname: Lau
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K. mjd13@cam.ac.uk.
authors.forename: Melinda J
authors.initials: MJ
authors.lastname: Duer
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000737:chemistry*; D000818:Animals; D003094:Collagen / Q000737:chemistry*; D006031:Glycosylation; D008956:Models, Chemical; D019906:Nuclear Magnetic Resonance, Biomolecular; D012267:Ribosemonophosphates / Q000737:chemistry*
chemical_list: D012267:Ribosemonophosphates; D000246:Adenosine Diphosphate Ribose; C031626:ribose-5-phosphate; D003094:Collagen
keywords: ADP-ribose; Maillard reaction; advanced glycation endproducts; ribose; ribose-5-phosphate; solid-state NMR