Inhibition of Aspartate Aminotransferase by Glycation In Vitro Under Various Conditions |
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Authors: | Jaroslav Dr?ata Martin Beránek VladimÍr Pali?ka |
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Institution: | 1. Department of Biochemical Sciences, Charles University Faculty of Pharmacy and Research Centre LN00B125, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic;2. Institute of Clinical Biochemistry and Diagnostics, Faculty Hospital, 500 05 Hradec Králové, Czech Republic |
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Abstract: | Incubation of 50 mM d -glucose with aspartate aminotransferase (AST, EC 2.6.1.1) preparations (purified pig heart enzyme or a rat liver 20,000 × g supernatant) at 25°C had no effect on enzyme activity. 50 mM d -fructose or d -ribose gradually inhibited pig heart AST under the same conditions to zero activity after 14 days. 50 mM dl -glyceraldehyde decreased enzyme activity to zero after 6 days of incubation. The inhibition of pig heart AST by 50 mM d -fructose or d -ribose was marked even at a temperature of 4°C but it was less pronounced than at 25°C. There was no effect of 0.5 mM 2-oxoglutarate on AST activity during incubation, while the presence of 25 mM l -aspartate decreased it rapidly. 0.5 mM 2-oxoglutarate partly prevented inhibition of AST by d -ribose or d -fructose, while an analogous experiment with 25 mM aspartate resulted in a rapid decline similar to that in the absence of sugars. |
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Keywords: | Aspartate Aminotransferase Transaminase Inhibition Glycation Monosaccharides |
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