SENS PubMed Publication Search
A new glycation product ‘norpronyl-lysine’ and direct characterization of cross linking and other glycation adducts: NMR of model compounds and collagen.
Biosci Rep. 2014 Feb 12. [Epub ahead of print] doi:
Bullock PT, Reid DG, Chow WY, Lau WP, Duer MJ
Abstract:
NMR is ideal for characterizing non-enzymatic protein glycation, including AGEs (advanced glycation end products) underlying tissue pathologies in diabetes and ageing. Ribose, ribose-5-phosphate (R5P) and ADP-ribose (ADPR) 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 within hours. Solid state NMR (ssNMR) 13C-13C correlation spectroscopy identifies several crosslinking adducts such as the newly identified norpronyl-lysine, in situ, from the glycating reaction of 13C5-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, poly-L-lysine (PLL)) catalyzed 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.
PMID: 24517485
Free Full-Text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3953948/