D-Ribose induced glycoxidative insult to hemoglobin protein: An approach to spot its structural perturbations

Glycation of biological macromolecule leads to the establishment of advanced glycation end products (AGES) having implications in metabolic disorders. D ribose appears to be the most reactive among the naturally occurring sugars and contribute significantly to the glycation reactions in vivo, however, no report have been published yet to discuss D ribose induced glycation of hemoglobin (Hb). Therefore, the present study was designed to investigate D ribose induced glycoxidative damage to Hb protein. Briefly, the commercially available Hb was glycated with D ribose for varying time intervals. The structural perturbation induced in glycated Hb (GHb) was confirmed by biophysical techniques viz., UV-visible, fluorescence spectroscopy, circular dichroism, Fourier transform infrared spectroscopy, dynamic light scattering, MALDIthermal denaturation by UV-visible spectrophotometer and DSC. Biophysical techniques confirm the secondary and tertiary structural perturbation in GHb as compared to native Hb. The values of carbonyl content, hydroxy methyl furfural, thiobarbituric acid reactive substance and nitro blue tetrazolium were found to be increased and free lysine and free arginine content were decreased in the GHb due to structural change. Thus, results of this study have established that glycation with D ribose lead to the structural changes in the native Hb which might play an important role in pathophysiology metabolic diseases. (C) 2018 Elsevier B.V. All rights reserved