In enzymology, a 4-acetamidobutyryl-CoA deacetylase (EC 3.5.1.51) is an enzyme that catalyzes the chemical reaction

4-acetamidobutanoyl-CoA + H₂O ${\displaystyle \rightleftharpoons }$ acetate + 4-aminobutanoyl-CoA

Thus, the two substrates of this enzyme are 4-acetamidobutanoyl-CoA and H₂O, whereas its two products are acetate and 4-aminobutanoyl-CoA.

This enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amides. The systematic name of this enzyme class is 4-acetamidobutanoyl-CoA amidohydrolase. Other names in common use include aminobutyryl-CoA thiolesterase, and deacetylase-thiolesterase.

• Ohsugi M, Kahn J, Hensley C, Chew S, Barker HA (1981). "Metabolism of L-beta-lysine by a Pseudomonas. Purification and properties of a deacetylase-thiolesterase utilizing 4-acetamidobutyryl CoA and related compounds". J. Biol. Chem. 256 (14): 7642–51. PMID 6788773.