THE IN-VITRO GLYCATION OF LYSOZYME AND THE INFLUENCE OF BUFFER CONCENTRATION INVESTIGATED BY MASS-SPECTROMETRY

The non-enzymatic reactions between glucose or fructose with lysozyme, performed under pseudo-physiological conditions, have been studied by means of matrix-assisted laser desorption/ionization mass spectrometr y. Phosphate buffer at concentrations of 0.05, 0.2 and 0.5 M has been employed. The formation of glycated proteins as well as of cross-linki ng products has been always observed. In the case of glucose, high pho sphate buffer concentrations affect the glycation kinetics and promote the formation of cross-linking products. With fructose, such influenc e is moderate, the reaction kinetics being mainly influenced by the hi gher reactivity of the sugar.