Background: Non-enzymatic glycation of proteins plays a significant role in the pathogenesis
of secondary diabetic complications via the formation of advanced glycation end products (AGEs) and
increased oxidative stress. Methylglyoxal (MG), a highly reactive dicarbonyl of class α-oxoaldehyde
that generates during glucose oxidation and lipid peroxidation, contributes to glycation.
Objective: This comparative study focuses on methylglyoxal induced glycoxidative damage suffered by
immunoglobulin G (IgG) and fibrinogen, and to unveil implication of structural modification of serum
proteins in diabetes-associated secondary complications.
Methods: The methylglyoxal induced structural alterations in IgG and fibrinogen were analyzed by UVvis,
fluorescence, circular dichroism and Fourier transform infrared (FT-IR) spectroscopy. Ketoamine
moieties, carbonyl contents, 5-Hydroxymethylfurfural (HMF) and malondyaldehyde were also quantified.
Free lysine and arginine estimation, detection of non-fluorogenic carboxymethyllysine (CML) and
fibril formation were confirmed by thioflavin T (ThT) assay.
Results: Structural alterations, increased carbonyl contents and ketoamines were reported in MG glycated
IgG and fibrinogen against their native analogues.
Conclusion: The experiment results validate structural modifications, increased oxidative stress and
AGEs formation. Thus, we can conclude that IgG-AGEs and Fib-AGEs formed during MG induced glycation
of IgG and fibrinogen could impede normal physiology and might initiates secondary complications
in diabetic patients.