A Molecular Mechanism for Direct Sirtuin Activation by Resveratrol
Figure 4
Effects of resveratrol and piceatannol on Sirt3 and Sirt5 deacetylation activities against fluorophore-free peptides and proteins.
A Overlay of the Sirt5/FdL1/resveratrol (FdL1 in green, activator omitted for clarity) and Sirt5/succinylated H3 peptide/NAD+ (H3 peptide in atom type coloring, NAD+ omitted for clarity) complexes. The fluorophore occupies the site normally accommodating residues of the substrate polypeptide. B Overlay of Sirt5/FdL1/resveratrol (FdL1 omitted for clarity) and Sirt5/succinylated H3-peptide/NAD+ complex. Ligands are colored according to atom types with carbon atoms in green (resveratrol), yellow (H3 peptide), and blue (NAD+). C+D Sirt5-dependent deacetylation of Prx1-Lys197 peptide (C) and Prx1 protein specifically acetylated at Lys197 (D) is activated by resveratrol-related compounds. E Sirt5-dependent deacetylation of Cytochrome c determined in an ELISA shows that resveratrol and piceatannol stimulate this activity (which leads to a loss of signal in this assay). F Dose-reponse experiment for the piceatannol-dependent stimulation of Cytochrome c deacetyalation by Sirt5. Shown is the loss in absorption at different piceatannol concentrations relative to untreated Cytochrome c. G Sirt3-dependent GDH deacetylation tested in an ELISA (deacetylation decreases absorbance) shows an inhibitory effect of resveratrol. Error bars represent standard errors of linear fits to time-series experiments (C+D) or standard deviations (E–G), respectively.