The lysine glycation 1. A preliminary investigation on the products arising from the reaction of protected lysine and D-glucose

Abstract

The nature of the products arising from a 10 days, sterile incubation at 37°C and pH 7.2 of a 1:1 mixture of N-α-(p-tosyl)-lysine-methylesterhydrochloride and anhydrous D-glucose was investigated by fast atom bombardment mass spectrometry and(1)H and(13)C nuclear magnetic resonance spectroscopies. Differently to the reactivity usually described on the basis of other analytical techniques, FAB mass spectrometric measurements indicate the occurrence of the reaction of protected lysine with more than one D-glucose molecule.

Structural studies of the Maillard reaction products of a protein using ion trap mass spectrometry

“…The 1 H and 13 C NMR spectra of Ac‐Lys* indicate that various tautomeric products are generated by the Maillard reaction. For the assignment of the signals obtained by NMR, the published chemical shifts and the coupling constants of various tautomers of the Amadori compounds of amino acids and sugars were very helpful 2–4. The structures of the Amadori compounds of glycine, β ‐alanine, γ ‐aminobutyric acid, δ‐aminovaleric acid, ϵ ‐aminocaproic acid and N α ‐formyl‐ L ‐lysine with D ‐glucose have already been determined by Mossine et al 4 We used the chemical shifts of the Amadori compound of N α ‐formyl‐ L ‐lysine with D ‐glucose ( N α ‐formyl‐Lys*) as the references for the structural characterization of Ac‐Lys*.…”

“…In the early stage, a sugar reacts with the amino groups of an amino acid or a protein to form a stable Amadori rearrangement product, via a Shiff base (Scheme ). The structures of the early stage products of amino acids with D ‐glucose have been studied 2–4. In the advanced stage, many different, complex reactions occur, and consequently yellow–brown, cross‐linked fluorescent products, called advanced glycation end (AGE) products, are produced 5, 6.…”

In situcharacterization of advanced glycation end products (AGEs) in collagen and model extracellular matrix by solid state NMR

“…The complexity of the glycation process is compounded by its proceeding with a distinct lack of consistency under apparently consistent conditions, rendering pathways and structural consequences of glycation extremely difficult to study systematically in vivo . This complexity is exacerbated by the occurrence of reactions which are hard to predict even with simple model compounds, 14 and the poorly understood catalytic influence of certain biomolecules and ions. 15…”

Diabetes and mass spectrometry

“…In view of the controversial results obtained by MS and other analytical techniques, the identification of possible molecular species structurally different from FFI but containing substructure(s) accounting for the absorbency and RIA responses57, 58 was retained of interest. The furoyl cation was therefore chosen for parent ion spectroscopy experiments59. This technique identified all molecular species in the hydrolysed collagen samples exhibiting furanyl in their substructure.…”