The sirtuins represent a distinct class of trichostatin A-insensitive lysyldeacetylases (class III HDACs) and have been shown to catalyze a reaction that couples lysine deacetylation to the formation of nicotinamide and O-acetyl-ADP-ribose from NAD+ and the abstracted acetyl group. There are seven human sirtuins，which have been designated SIRT1-SIRT7. Recently，SIRT7 has been shown to activate transcription by RNA polymerase I and deacetylate p53. SIRT7 prevents progressive functional deterioration of the heart，and is suggested to play an important role in regulation of stress responses and cell death in the heart. This antibody especially recognizes the cleaved sirtuin-7.
