(2) special transport vehicles for transport China giant core technology benefits electronic material localization The general function of deacetylation with the lysine residues is carried out by HDAC enzymes. Apart from this pair of HDACs there exists another enzyme which performs a similar function. The name with this enzyme is SIRT1 also it removes the acetyl group by way of a very unique mechanism. The end product of this enzyme mediated reaction is nicotinamide. Removal of acetyl group by HDACs doesn't involve NAD+ hydrolysis. Inhibitors like trichostatin A, which show specific action against HDACs don't have any action against SIRT1.