Protein oxidation, the process caused especially by reactive oxygen and nitrogen species, is thought to play a major role in various oxidative processes within cells and is implicated in the development of many human diseases. This review provides a brief overview of the protein oxidation with the emphasis on the types of oxidation (oxidation of protein backbone and amino acid residues side chains, site-specific metal-catalysed protein oxidation), oxidationdependent generation of protein hydroperoxides, carbonyl derivatives and protein-protein cross-linkages. Nonenzymatic glycoxidation (also known as Maillard reaction) as an important factor of protein damage, consequences of oxidative protein impairment and related diseases as well as means of monitoring and assessment of protein modifications are discussed.

• MeSH
• aminokyseliny chemie   MeSH
• diabetická retinopatie patologie   MeSH
• diabetické neuropatie patologie   MeSH
• katarakta patologie   MeSH
• kyslík metabolismus   MeSH
• lidé MeSH
• Maillardova reakce * MeSH
• oxidace-redukce * MeSH
• oxidační stres fyziologie   MeSH
• proteiny chemie   MeSH
• reaktivní formy dusíku metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• aminokyseliny MeSH
• kyslík MeSH
• proteiny MeSH
• reaktivní formy dusíku MeSH
• reaktivní formy kyslíku MeSH

Glycation is a process closely related to the aging and pathogenesis of diabetic complications. In this process, reactive α-dicarbonyl compounds (e.g., methylglyoxal) cause protein modification accompanied with potential loss of their biological activity and persistence of damaged molecules in tissues. We suppose that glutathione S-transferases (GSTs), a group of cytosolic biotransformation enzymes, may be modified by glycation in vivo, which would provide a rationale of its use as a model protein for studying glycation reactions. Glycation of GST by methylglyoxal, fructose, and glucose in vitro was studied. The course of protein glycation was evaluated using the following criteria: enzyme activity, formation of advanced glycation end-products using fluorescence and western blotting, amine content, protein conformation, cross linking and aggregation, and changes in molecular charge of GST. The ongoing glycation by methylglyoxal 2 mM resulted in pronounced decrease in the GST activity. It also led to the loss of 14 primary amino groups, which was accompanied by changes in protein mobility during native polyacrylamide gel electrophoresis. Formation of cross links with molecular weight of 75 kDa was observed. Obtained results can contribute to understanding of changes, which proceed in metabolism of xenobiotics during diabetes mellitus and ageing.

• MeSH
• diabetes mellitus enzymologie   MeSH
• fruktosa chemie   metabolismus   MeSH
• glukosa chemie   metabolismus   MeSH
• glutathiontransferasa chemie   metabolismus   MeSH
• katalýza MeSH
• lidé MeSH
• produkty pokročilé glykace chemie   metabolismus   MeSH
• pyruvaldehyd chemie   metabolismus   MeSH
• stárnutí metabolismus   MeSH
• xenobiotika chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• fruktosa MeSH
• glukosa MeSH
• glutathiontransferasa MeSH
• produkty pokročilé glykace MeSH
• pyruvaldehyd MeSH
• xenobiotika MeSH

Glycation is a process closely related to the aging and pathogenesis of diabetic complications. Reactive alpha-dicarbonyl compounds (e.g., methylglyoxal) are formed during middle stage of glycation reaction. Compounds that would inhibit the glycation process have been seeked for years. The objective of this study was to investigate the inhibitory effect of hydroxycitric (0.25-2.5 mM) and uric acid (0.4-1.2 mM) on middle stage of protein glycation in vitro using the model containing aspartate aminotransferase (AST) and 0.5 mM methylglyoxal. Hydroxycitric acid, at all tested concentrations, reduced AST activity decrease and formation of fluorescent AGEs during incubation of the enzyme with methylglyoxal at 37 degrees C. This compound also prevented formation of high-molecular weight protein cross-links and changes in molecular charge of AST caused by glycation. Uric acid showed no positive anti-glycation activity. The results support the hypothesis that hydroxycitric acid has beneficial effects in controlling protein glycation.

• MeSH
• aspartátaminotransferasy chemie   metabolismus   MeSH
• citráty farmakologie   MeSH
• fluorescence MeSH
• glykosylace účinky léků   MeSH
• kvarterní struktura proteinů MeSH
• kyselina močová farmakologie   MeSH
• ornithin analogy a deriváty   metabolismus   MeSH
• produkty pokročilé glykace metabolismus   MeSH
• pyrimidiny metabolismus   MeSH
• pyruvaldehyd farmakologie   MeSH
• reagencia zkříženě vázaná farmakologie   MeSH
• Sus scrofa MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• argpyrimidine MeSH Prohlížeč
• aspartátaminotransferasy MeSH
• citráty MeSH
• hydroxycitric acid MeSH Prohlížeč
• kyselina močová MeSH
• ornithin MeSH
• produkty pokročilé glykace MeSH
• pyrimidiny MeSH
• pyruvaldehyd MeSH
• reagencia zkříženě vázaná MeSH