Figure 2. Examples of fructation products expected to form in vitro as a basis for structures resulting from the enzymatic action of GfrE in bacteria.

(A) The non-enzymatic reaction of fructose with ϵ-amino-lysine residues leads to the formation of various possible isomeric products (so-called Heyns rearrangement products), depending on whether the initial Schiff base isomerizes via the 1,2-, or 2,3-enolization pathway (B) Wiame et al. [14] have now identified not only enzymes that can catalyse and deglycate the formation of phosphorylated glycated lysine from glucose 6-phosphate, but also that of glucoselysine 6-phosphate from fructose 6-phosphate and ϵ-amino-lysine.