2.7. SIRT3 deacetylase-activity assay in human NP cells

The deacetylase activity of SIRT3 was determined with a SIRT3 Fluorescent Activity Assay/Drug Discovery Kit (BML-AK557-0001; Enzo Life Sciences, Plymouth Meeting, PA, USA), following the manufacturer's protocol. Briefly, the mitochondrial extract (5 μg) was incubated with the FLUOR DE LYS^®-SIRT2 buffer at 37 °C for 60 min, followed by incubation with FLUOR DE LYS® Developer II buffer at 37 °C for 40 min. The fluorescence intensity was measured using a microtiter plate fluorimeter, with excitation at 360 nm and emission at 460 nm. The “blank” value of assay buffer was subtracted from all other values.