Advanced glycation endproducts analysis of glucosamine with reducing sugars, DNA nucleosides and serum proteins

Udayan Dutta, University of Rhode Island

Abstract

Advanced glycation endproducts (AGE) are a complex and heterogeneous group of compounds formed by the nonenzymatic reactions of reducing sugars with amino acids and proteins. The reaction is called the Maillard reaction and is central to all protein glycation studies. Accumulation of AGE in human tissue has been associated with the pathology of various diseases like diabetes, Alzheimer's disease, renal failure and ageing and has generated great interest in methods for characterizing the glycated products. Glucosamine GlcN is an unregulated high profile dietary supplement used for the treatment of osteoarthritis with few side effects. There is very little understanding on why the drug is effective or if there are any long-term effects of this treatment. ^ One study investigated the reaction of reducing sugars with the free amino group of GlcN. Capillary electrophoresis proved extremely effective in monitoring the AGE species in all the reducing sugar/GlcN model systems. The study also demonstrated glyoxylate as an effective advanced glycation like endproducts (AGEL) precursor in vitro, by monitoring its reaction with the amino acids lysine and arginine and the amino group of glucosamine by the use of capillary electrophoresis (CE) and high performance liquid chromatography. ^ A second study monitored the nonenzymatic glycation of DNA nucleosides in vitro and characterized the formation of nucleoside AGE's. Deoxyguanosine exhibited the highest rate of glycation with glyceraldehydes. Similar to proteins, DNA nucleoside AGE formation is affected by several factors of which the most important included the chemical structure and concentration of reactants including the ionic strength, temperature and time of incubation. ^ A third study investigated the effect of nonenzymatic glycation on the secondary structure of human serum albumin (HSA) and immunoglobulin G (IgG) in vitro utilizing CE, circular dichroism (CD), thermal melting (Tm) and UV-fluorescence spectroscopy. The effect of various reducing sugars on the secondary structure of HSA and IgG is analyzed by CD and Tm. The study utilized a combination of analytical techniques to analyse, separate, characterize and identify advanced glycation endproducts (AGE) formed in vitro by GlcN nonenzymatically reacting with reducing sugars, amino acids, DNA nucleosides and serum proteins which are all potential glycation substrates. ^

Subject Area

Chemistry, Biochemistry

Recommended Citation

Udayan Dutta, "Advanced glycation endproducts analysis of glucosamine with reducing sugars, DNA nucleosides and serum proteins" (2005). Dissertations and Master's Theses (Campus Access). Paper AAI3188840.
http://digitalcommons.uri.edu/dissertations/AAI3188840

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