Deuterium Incorporation Protects Cells from Oxidative Damage

Figure 7

Effects of D-AA on protein synthesis and damage. (a) Protein synthesis by rabbit reticulocyte lysate translating endogenous messengers measured by a radioactive assay in the presence of D-AA at the concentration indicated in the figure. The extent of translation was measured as the incorporation into proteins of [³H]leucine and expressed as percentage activity. (b) Protein synthesis (as described in panel (a)) performed in the absence of the indicated AA (minus AA), after the addition of the corresponding AA (minus AA + AA), or substituting the deuterated form (50 μM) for the indicated AA (minus AA + D-AA). (c) Protein synthesis performed (as in panel (b)) with gel-filtered rabbit reticulocyte lysate. (d) Protein synthesis by rabbit reticulocyte lysate translating the mRNA encoding Renilla reniformis luciferase measured by a luminometric assay in the absence and in the presence of added Pro or substituting D-Pro (50 μM) for Pro. The extent of translation was measured as the emission of luminescence and expressed as percentage activity. (e) Protein synthesis in Jurkat cells preincubated with D-AA. The rate of translation was measured as the incorporation into proteins of [³H]leucine and expressed as percentage activity. (f) Protein carbonyl formation in Jurkat cells preincubated for 20 h in the absence (control) or in the presence of D-Pro and subsequently untreated or treated with hydrogen peroxide. The carbonyl levels were 1.8 and 2.7 nmol/mg of protein in the control untreated cells or control H₂O₂-treated cells, respectively. (g) Advanced oxidation protein products in Jurkat cells preincubated for 20 h in the absence (control) or in the presence of D-Pro (see Materials and Methods). The level of advanced oxidation protein product in the control cells was 0.8 nmol/mg of protein. , , and .

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