2’-Deoxyribose Mediated Glycation Leads to Alterations in BSA Structure Via Generation of Carbonyl Species

Abstract

The non-enzymatic glycosylation is a very common phenomenon in the physiological conditions which is mediated by distinct chemical entities containing reactive carbonyl species (RCS) and participate in the modification of various macromolecules particularly proteins. Till date, various carbonyl species, i.e., glucose, fructose, D-ribose and methylglyoxal have been used frequently to assess the in-vitro non-enzymatic glycosylation. Similarly, 2'-Deoxyribose is one of the most abundant reducing sugar of the living organisms which forms the part of deoxyribonucleic acid and may react with proteins leading to the production of glycation intermediates, advanced glycation end products (AGEs) and highly reactive RCS. Thymidine phosphorylase derived degradation of thymidine contributes to the formation of 2'-Deoxyribose, therefore, acting as a major source of cellular 2'-Deoxyribose. Since albumin is a major serum protein which plays various roles including binding and transporting endogenous and exogenous ligands, it is more prone to be modified through different physiological modifiers; therefore it may serve as a model protein for in-vitro experiments to study the effect of 2’Deoxyribose mediated modifications in the protein. In this study, Bovine Serum Albumin (BSA) was glycated with 50 and 100 mM 2'-Deoxyribose followed by examining secondary and tertiary structural modifications in BSA as compared to its native (unmodified) form by using various physicochemical techniques. We evident a significant modification in 2'-Deoxyribose-glycated BSA which was confirmed through increased hyperchromicity, keto amine moieties, carbonyl and hydroxymethyl furfural content, fluorescent AGEs, altered secondary structure conformers (α helix and β sheets), band shift in the amide-I region and diminished free lysine and free arginine content. These modifications were reported to be higher in 100 mM 2'-Deoxyribose-glycated BSA than 50 mM 2'-Deoxyribose-glycated BSA. Our findings also demonstrated that the rate of glycation is positively affected by the increased concentration of 2'-Deoxyribose. The results of the performed study can be implied to uncover the phenomenon of serum protein damage caused by 2'-Deoxyribose leading towards diabetic complications and number of AGE-related diseases.

Nonenzymatic glycosylation of isolated human immunoglobulin‐G by D‐ribose

“…The UV‐Vis spectra of the N‐IgG and glycated IgG (D‐rib‐IgG) samples were measured postincubation (1–12 days with 10 mM and 1–8 days with 100 mM D‐ribose, respectively). The absorbance was recorded using a quartz 1 cm path‐length cuvette on a Biospectrum‐Spectrophotometer (Eppendorf) across the wavelength range of 240–800 nm 6 . The absorbance spectra profile at 278 nm was assessed individually for each aliquot of the sample mixtures.…”

“…The absorbance was recorded using a quartz 1 cm path-length cuvette on a Biospectrum-Spectrophotometer (Eppendorf) across the wavelength range of 240-800 nm. 6 The absorbance spectra profile at 278 nm was…”

“…Besides the amino‐terminal of proteins, the epsilon (ε) amino groups of lysine and guanidino group of arginine are considered to be involved in the glycation process 4 . The in vitro glycation reaction occurs by incubating proteins with reducing sugars or reactive carbonyl species such as glucose, fructose, ribose, glyoxal (GO), and methylglyoxal (MG) 5–7 . The susceptible nucleophilic amino group involved in reversible condensation with a carbonyl group of the reducing sugar is the possible mechanism that contributes to elevating the formation of unstable Schiff's base, an intermediate of the glycation process, which can further undergo a spontaneous multistep rearrangement and acid‐base reactions to form unstable Amadori products 8–11 .…”

“…4 The in vitro glycation reaction occurs by incubating proteins with reducing sugars or reactive carbonyl species such as glucose, fructose, ribose, glyoxal (GO), and methylglyoxal (MG). [5][6][7] The susceptible nucleophilic amino group involved in reversible condensation with a carbonyl group of the reducing sugar is the possible mechanism that contributes to elevating the formation of unstable Schiff's base, an intermediate of the glycation process, which can further undergo a spontaneous multistep rearrangement and acid-base reactions to form unstable Amadori products. [8][9][10][11] The intermediate Amadori products may further undergo rearrangements, dehydrations, and cyclizations to form highly stable advanced glycation end products (AGEs).…”

Metformin encapsulated gold nanoparticles (MTF‐GNPs): A promising antiglycation agent

“…Glycation is resulted by the reaction (nonenzymatic) of free reducing sugars with amino groups of proteins, DNA, and lipids. As the reaction progresses, unstable Schiff bases are generated and converted into an early glycation product called the Amadori product 6,7 . As these intermediates proceed through a series of complicated processes, they produce fluorescent and cross‐linked derivatives known as advanced glycation end products (AGEs).…”