Glycation-Induced Structural Alteration in Biomolecules ^†

Abstract

Hyperglycaemia leads to an accumulation of harmful substances in the body due to a process known as glycation. In this process, carbonyl groups of sugars interact with the amino groups of other biomolecules, ultimately resulting in the formation of advanced glycation end products. These products have been implicated in various pathophysiological conditions like diabetes, Parkinson’s, Alzheimer’s, cataracts, etc. Although the exact mechanism by which AGEs bring about changes in the structure of biomolecules is not known, it is assumed that cross-linking, aggregation, oxidation, and precipitation of proteins are some probable processes that are responsible for the structural and functional changes in biomolecules. In our study, we have used glucose and BSA as the in vitro model system to study the structural alterations they produce and the reversal of these alterations induced by natural products. A range of spectroscopic and electrophoretic tools were used to assess the alteration in BSA structure. The amounts of glycation products were also quantified by colourimetric and spectrofluorometric methods. The results indicate that glucose induces severe changes in the conformation of BSA and the presence of thymoquinone suppresses these alterations. Similarly, a significant amount of glycation products were generated in the in vitro system and were inhibited by the natural product. It can be concluded that glucose brings about conformational changes in proteins and causes the accumulation of glycation products during sustained hyperglycaemia.