Towards a unifying mechanistic picture of glycation-induced crosslinking of protein (360G-Wellcome-214069_Z_18_Z)

Non-enzymatic glycation of protein leads to ternary crosslinks involving reducing sugars, lysine and arginine residues (e.g. glucosepane, pentosidine, and DOGDIC), which alter the physical properties of long-lived fibrous tissue and are strongly correlated with the severity of diabetes in individuals. However, it remains unclear whether there is a causal link between these crosslinks and microvascular complications of diabetes. Furthermore, the mechanism by which initial adducts between glucose and lysine (Amadori products) are transformed into highly reactive intermediates that lead to crosslinking is poorly understood. With experiments employing 2H and 13C-labelled glucose, novel synthetic reagents, HPLC/MS analysis and DFT computation, we intend to describe, in great molecular detail, the origin of advanced glycation end-products (AGEs) derived from lysine, arginine and glucose. In particular, we will test the hypothesis that a hitherto unexplored through-space 1,5-hydrogen shift and the catalytic role of protein environment is pivotal in determining the fate of the Amadori product. The results will form the basis of a larger collaborative programme that will predict sites on fibrous tissue where crosslinks are likely to form, and develop well-defined protein platforms for both exploring RAGE/lectin activation and identifying antibodies and small molecules as biological probes and therapeutic agents for diabetes.