An in vitro approach to unveil the structural alterations in d-ribose induced glycated fibrinogen

Abstract

Plasma proteins persistently bear non-enzymatic post-translational modifications (NEPTM) that proceeds with nucleophilic addition between free amino groups of proteins, and carbonyl group of reducing sugars. Glycation, a prevalent NEPTM rush by the high availability of reducing sugars results in the generation of advanced glycation end products (AGEs). Plasma proteins are more vulnerable to glycation because of the presence of multiple glycation sites and are widely studied. However, fibrinogen glycation is less studied. Therefore, it was designed as an in vitro study to elucidate d-ribose mediated glycative damage suffered by fibrinogen protein at secondary and tertiary structure level. The glycation induced structural alterations were analyzed by UV-vis, fluorescence, circular dichroism, scanning electron microcopy and Fourier transform infrared spectroscopy. Glycation induced protein aggregation and fibrils formation was confirmed by thioflavin T and congo red assay. Moreover, molecular docking study was performed to further validate physicochemical characterization. Structural alterations, increased ketoamines, protein carbonyls and HMF contents were reported in d-ribose glycated fibrinogen against their native analogues. The results validate structural perturbations, increased glycoxidative stress and AGEs formation, which might influence normal function of fibrinogen especially blood coagulation cascade. Thus, we can conclude that under diabetes induced hyperglycemic state in physiological systems, d-ribose induced fibrinogen glycation might play a crucial role in the onset of micro- and macro-vascular complications, thereby worsen the diabetes associated secondary disorders. Moreover, this in vitro study might pave a path to choose fibrinogen as a future biomarker for the early detection of diabetes mediated vascular complications. Communicated by Ramaswamy H. Sarma