Role of NAD(+) in the deacetylase activity of the SIR2-like proteins.
Biochemical and biophysical research communications
confidence
Key findings
Mechanistic biochemistry: NAD+ hydrolyzed to ADP-ribose and nicotinamide 1:1:1 with deacetylation; enzyme-ADP-ribose intermediate required.
View source on PubMed (PMID 11095969) ↗
- Sample size
- N/A
- Population
- In vitro enzymatic study (SIR2-like proteins, no clinical/biological population)
- Dosing
- N/A
- Duration
- N/A
- Route
- N/A
- Blinding
- not_reported
- Controls
- none
- Drug class
- coenzyme
Full abstract
In this report we describe the role of NAD(+) in the deacetylation reaction catalyzed by the SIR2 family of enzymes. We first show that the products of the reaction detected by HPLC analysis are ADP-ribose, nicotinamide, and a deacetylated peptide substrate. These products are in a 1:1:1 molar ratio, indicating that deacetylation involves the hydrolysis of one NAD(+) to ADP-ribose and nicotinamide for each acetyl group removed. Three results suggest that deacetylation requires an enzyme-ADP-ribose intermediate. First, the enzyme can promote an NAD(+) if nicotinamide exchange reaction that depends on an acetylated substrate. Second, a non-hydrolyzable NAD(+) analog is a competitive inhibitor of the enzyme, and, third, nicotinamide shows product inhibition of deacetylase activity.