Non-enzymatic glycation and oxidation of self-proteins, causing formation and accumulation of advanced glycation end products (AGEs), have been reported in an array of pathologies, including systemic lupus erythematosus (SLE). Such modifications may generate neo-epitopes, break immunological tolerance, and induce antibody response. In this study, we have first analysed the structural modifications of whole histone in the presence of deoxyribose followed by oxidation with hydroxyl radicals.
View Article and Find Full Text PDFThe purpose of the present study is to explore the effects of endogenous stressors on structure and function of rheumatoid arthritis (RA) patients' albumin. In contrast to glycated-albumin or nitro-oxidized-albumin, high titre antibodies against glyco-nitro-oxidized-albumin were found in the sera of RA patients. Also, compared to the other two modified forms of albumin, glyco-nitro-oxidized-albumin showed highest percent inhibition.
View Article and Find Full Text PDFThe minor fraction of methylglyoxal that is not metabolized in healthy humans reacts with macromolecules to form AGEs. In diabetics, the formation of MG is accelerated; its level may be enhanced multifold. The glyoxalase enzymes responsible for the regular and effective clearance of excess methylglyoxal may become defective in diabetes mellitus leading to its retention in cells and plasma.
View Article and Find Full Text PDFRheumatoid arthritis (RA), a chronic inflammatory disease, and its exact aetiology is not defined clearly. The free radicals produced in large amount in RA are associated with alteration in molecular structure resulting in glycation of proteins. As a result of glycation, advanced glycation end products (AGEs) produced.
View Article and Find Full Text PDFThe micro- and macro-complications in diabetes mellitus (DM) mainly arise from the damage induced by Amadori and advanced glycation end products, as well as the released free radicals. The primary goal of DM treatment is to reduce the risk of micro- and macro-complications. In this study, we looked at the efficacy of aminoguanidine (AG) to prevent the production of early glycation products in alloxan-diabetic rabbits.
View Article and Find Full Text PDFAlbumin, an important serum protein, is continuously exposed to various oxidizing/nitrating and glycating agents. Depending upon the nature/concentration of reactive species present, the protein may be glycated, oxidized/nitroxidized or glyco-nitro-oxidized. Peroxynitrite is a powerful nitroxidant and has been reported to damage a wide array of macromolecules.
View Article and Find Full Text PDFCarbamylation is the non-enzymatic reaction between isocyanic acid and macromolecules (mainly proteins) which results in carbamylation-derived products (CDPs) generation, wherein the macromolecules show altered structure and function. In this study, we examined the modifications caused in human serum albumin (HSA) upon interaction with potassium cyanate (KCNO). HSA was incubated with varying concentrations of KCNO for 6 h at 37 °C.
View Article and Find Full Text PDFSystemic lupus erythematosus (SLE) is an inflammatory, autoimmune disorder of unknown etiology. The inflammatory stress in SLE patients may modify macromolecules and produce structural/functional abnormalities. The present study is aimed at examining the consequences of stresses on the structure of albumin in SLE patients.
View Article and Find Full Text PDFRheumatoid arthritis (RA) is an autoimmune disease whose major clinical consequence is inflammation of small joints and contiguous structures. Oxidative and nitrosative stress along with increased formation of advanced glycation end products (AGEs) play an important role in the disease process. Generation of reactive species during glycation of proteins further adds to the oxidative and nitrosative stress.
View Article and Find Full Text PDFCarbamylation is an ubiquitous process in which cyanate (OCN) reacts with the N-terminal amino or ε-amino moiety and generates α-carbamyl amino acids and ε-carbamyl-lysine (homocitrulline). The process leads to irreversible changes in protein charge, structure and function. In this study, we have investigated the effect of carbamyl (generated from potassium cyanate) on human serum albumin (HSA) structure and function.
View Article and Find Full Text PDFOver consumption of fructose may lead to obesity and dyslipidemia and cause fructosylation-induced alterations in the structure and function of proteins. The aim of this study was to investigate the role of fructosylated-HSA-AGE in the pathogenesis of fatty liver (NAFLD and NASH) by biochemical, immunological and histological studies. Immunogenicity of fructosylated-HSA-AGE was probed by inducing antibodies in rabbits.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
February 2019
Due to increased understanding of the damaging effects of glycation process, it is highly desirable to manage this process effectively either by prevention or by managing the consequences of glycation preferentially at early stage. The use of potential naturally occurring compounds as anti-glycating agents may provide an effective approach to control the development and progression of diabetic associated complications. In the present study, human serum albumin (albumin) was co-incubated with glucose and different concentrations of silibinin.
View Article and Find Full Text PDFBackground: Research reports support the statement that oxidative stress and inflammation are well-known risk factors for chronic kidney disease (CKD) in patients with diabetes. This study was designed to ascertain the associated role of oxidative stress parameters and inflammatory markers in diabetes and related CKD among the north Indian population.
Methods: The study was divided into three groups as healthy subjects (group 1), patients with diabetes without complication (group 2), and with CKD (group 3).
Carbamylation (or carbamoylation) is a non-enzymatic modification of biomolecules mediated by cyanate, a dissociation product of urea. Proteins are more sensitive to carbamylation. Two major sites of carbamylation reaction are: N -amino moiety of a protein N-terminus and the N -amino moiety of proteins' lysine residues.
View Article and Find Full Text PDFHyperglycaemia triggers increased production of methylglyoxal which can cause gross modification in proteins' structure vis-a-vis function though advanced glycation end products (AGEs). The AGEs may initiate vascular and nonvascular pathologies. In this study, we have examined the biochemical and biophysical changes in human IgG under normal and high glucose after introducing methylglyoxal into the assay mixture.
View Article and Find Full Text PDFFructose is a reducing and highly lipogenic sugar that has unique metabolic effects in the liver. Non-enzymatic fructosylation of proteins generates advanced glycation end products (AGEs). Human serum albumin (HSA) may undergo fructosylation vis-à-vis AGEs formation.
View Article and Find Full Text PDFChronic oxidative stress fuels pathogenesis of a large set of diseases. Oxidative stress is the cause and consequence of numerous diseases including type 1 diabetes mellitus (T1DM), in which there is selective destruction of insulin producing pancreatic β-cells. Studies have documented that hyperglycemia produces profound stress.
View Article and Find Full Text PDFJ Biomol Struct Dyn
September 2018
Human IgG is a defence protein and quite reactive to dicarbonyls. In this study, methylglyoxal-induced modification of IgG was examined by various biochemical and biophysical methods. The methylglyoxal-induced changes in IgG were monitored by UV-visible and fluorescence spectroscopy, Fourier transform infrared spectroscopy, 1-anilinonaphthalene-8-sulfonic acid (ANS), and thermal denaturation studies.
View Article and Find Full Text PDFSystemic lupus erythematosus (SLE) is an autoimmune disorder where the role of inflammatory processes in the etiopathogenesis is well documented. Despite extensive research, the trigger for initiation of the disease has not been identified. Peroxynitrite, a strong nitrating/oxidizing agent has been reported in SLE and other autoimmune diseases.
View Article and Find Full Text PDFHyperglycaemia induced non enzymatic glycation is accelerated in diabetic patients and aggressively involved in diabetes progression. Human serum albumin (HSA) is the most abundant protein in blood circulation. In hyperglycaemia, it undergoes fast glycation and results in the impairment of structure.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
March 2017
Glycosylation of DNA, proteins, lipids, etc. by reducing sugars, can lead to the formation of advanced glycation end products (AGEs). These products may accumulate and involve in the pathogenesis of a number of diseases, contributing to tissue injury via several mechanisms.
View Article and Find Full Text PDFAtherosclerosis has been linked to chronic inflammatory processes. Changes in the levels of lipoproteins, especially low-density lipoprotein or its variants, as well as inflammatory markers are risk factors for the atherosclerosis. In the present study, an experimental model of rheumatoid arthritis was developed by administrating collagen suspension intradermally in the tail region of Wistar albino rats.
View Article and Find Full Text PDFInt J Biol Macromol
November 2016
Early glycation products as well as advance glycation end products are involved in pathogenesis of diabetes. Most of studies carried out on AGEs and their possible role in assessing diabetes complications, whereas only a few were focused to highlight the role of Amadori products. In this study, an attempt has been made to investigate a structural and immunological characterizations of Amadori-albumin upon early glucosylation because albumin undergoes fast glycation under hyperglycaemic condition.
View Article and Find Full Text PDFIn this study, human serum albumin (HSA), the most abundant protein of blood plasma, was modified with varying concentrations of peroxynitrite. The peroxynitrite-induced changes in HSA was monitored by spectroscopy, SDS-PAGE, 1-anilinonaphthalene-8-sulfonic acid (ANS), thermal denaturation studies, and matrix-assisted laser desorption/inonization-time of flight mass spectrometry (MALDI-TOF MS). Aggregate formation was studied by thioflavin T binding and scanning electron microscopy (SEM).
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