Glycation of human erythrocyte glutathione peroxidase: Effect on the physical and kinetic properties

Aldehyde inhibition of antioxidant enzymes in the blood of diabetic patients

“…These differences probably reflect the peculiarities of the experimental conditions. Specifically, we incubated GPx for 1 h at 37°C with 10 mmol/L dicarbonyl and measured activity using tert ‐butyl hydroperoxide as a substrate, whereas in the other study this enzyme was incubated for 5 days with 20 mmol/L glyoxal or methylglyoxal using hydrogen peroxide as the substrate . The inhibitory effects of dicarbonyls also differed between the present and previous studies.…”

“…Specifically, we incubated GPx for 1 h at 37°C with 10 mmol/L dicarbonyl and measured activity using tert ‐butyl hydroperoxide as a substrate, whereas in the other study this enzyme was incubated for 5 days with 20 mmol/L glyoxal or methylglyoxal using hydrogen peroxide as the substrate . The inhibitory effects of dicarbonyls also differed between the present and previous studies. After 5 h incubation, we observed an approximate 40% decrease in the activity of native GPx, whereas in the previous study GPx activity was almost the same even after 5 days.…”

“…In a similar study, it was shown that glyoxal had no effect on the K m of GPx, whereas the K m was significantly increased by methylglyoxal . These differences probably reflect the peculiarities of the experimental conditions.…”

Effect of Essential Unsaturated Fatty Acids on Structure and Function of Catalase at High Glucose Concentration

“…Glycation of catalase causes structural damage and impairs physiological function of this enzyme. 18,19 However, the non-glycated setting of this anti-oxidant can protect other components against oxidative stress and also can decrease the risk of cardiovascular diseases. 20,21 In this study, we set out to assess the efficacy of some essential unsaturated fatty acids including arachidonic acid, linoleic acid and linolenic acid on structural and physiological function of catalase as an antioxidant enzyme in an in vitro setting.…”

Glycation vs. glycosylation: a tale of two different chemistries and biology in Alzheimer’s disease

“…However under pathological conditions, oxidant levels are increased because anti-oxidative enzymes are inactivated due to post-translational modifications including glycation and nitrosylation. Niwa reported that GPx is inactivated by glyceraldehyde, MG [34] and 3-DG [35], and that this results in oxidative stress. We previously reported that GPx undergoes nitrosylation.…”