Study on the nonenzymatic glycation of nucleosides/nucleotides and proteins with sugars: An in vitro investigation of advanced glycation endproducts (AGEs) formation

Advanced glycation endproducts (AGEs) are a complex and heterogeneous group 1 of compounds formed by the nonenzymatic reactions of the carbonyl groups of reducing sugars with the free amino groups of biomolecules. Nonenzymatic reactions can occur in vitro and in vivo and affect the structure, function and conformation of many biomolecules, and AGEs has been suggested to associate with the pathogenesis of various disease such as diabetes and Alzheimer disease. The increased number of reports on the nonenzymatic glycation of proteins and nucleic acids has generated great interest in the methods for characterization of AGEs. The lack of universally applicable method of AGE detection and measurement made it difficult to study and monitor glycation. Methylglyoxal and glyoxal are generated from the oxidation of carbohydrates and lipids, and like D-glucose have been shown to nonenzymatically react with proteins to form advanced glycation end products (AGEs). The objective of this study was to focus on purines and pyrimidines and to analyze these nucleic acids derived AGE adducts with glyoxal or methylglyoxal using a combination of analytical techniques. Other glycation precursors such as glyceraldehyde (GA), dihydroxyacetone (DHAP) also have been evaluate their glycation ability with nucleoside triphosphates. Studies using UV and fluorescence spectroscopy along with CE, HPLC, mass spectrometry provided for a thorough analysis of the nucleoside AGEs and human serum albumin (HSA) derived AGEs. Keywords. Advanced glycation endproducts; Maillard reaction products; glyoxal; methylglyoxal; 2\u27-deoxyguanosine; human serum albumin; nucleic acid