Figure 4
From: Yeast longevity promoted by reversing aging-associated decline in heavy isotope content
The metabolome shift by incorporation of deuterium through heavy water. See also Supplementary Figure S4. (a) The intracellular metabolome of BY4741 yeast cells upon D2O treatment at day 3 and day 7 was examined by LC-MS and clustered for all twenty proteinogenic amino acids (see Supplementary Figure S4A for global clustering). Two O2PLS-DA clustering models are superimposed to indicate the metabolome shift in amino-acid (AA) levels caused by D2O treatment. Green arrows indicate the direction from the model considering only 1H-isotopic AAs (H isotope model, R2Y=0.956, Q2=0.916, half transparent) to the model that sums all deuterium isotopes for each AA (All D-isotope model, R2Y=0.926, Q2=0.87, opaque). Each circle represents one of two technical replicates each from three biological samples. (b) The contribution of individual AA to the O2PLS-DA clustering models in a. Each circle represents an AA. Brown lines linked three AAs that exhibited minimal deuterium incorporation. (c) Extensive deuterium incorporation in two metabolites glutamine and glutamate. Each panel shows one AA and its deuterated derivatives (red trace) in yeast cells (BY4741) grown in medium without D2O or with 50% D2O at day 3. Accurate masses of relevant mass peaks (m/z) are indicated on each mass peak. (d) Intracellular metabolite levels shifted by D2O treatment. The intracellular sums of all hydrogen-isotopic metabolites for glucose, glutamine and glutamate from yeast cells (BY4741) at day 3 and day 7, as summarized in a, b, are plotted (n=3). P values for t-test versus levels in day 3 control are indicated above each bar. Error bars=s.e.m. (e) Medium metabolite consumption pattern reversed by D2O treatment. The medium levels of glucose, glutamine and glutamate in the first 3 days of culture after inoculation for two strains (DBY746, BY4741, n=3 each). The t-test P values are shown at each time point for comparison with starting medium levels. The control curves (0% D2O) for glutamine (middle panel) is the same as in Figure 1g. Error bars =s.e.m.
