Degrades bioactive fatty acid amides to their corresponding acids, with the following preference: N-palmitoylethanolamine > N-myristoylethanolamine > N-stearoylethanolamine > N-oleoylethanolamine > N-linoleoylethanolamine > N-arachidonoylethanolamine. H2O + N-hexadecanoylethanolamine = ethanolamine + hexadecanoate H2O + N-(long-chain fatty acyl)ethanolamine = a long-chain fatty acid + ethanolamine H2O + N-dodecanoylethanolamine = dodecanoate + ethanolamine H2O + N-tetradecanoylethanolamine = ethanolamine + tetradecanoate an N-acylsphing-4-enine + H2O = a fatty acid + sphing-4-enine H2O + N-hexadecanoylsphing-4-enine = hexadecanoate + sphing-4-enine H2O + N-dodecanoylsphing-4-enine = dodecanoate + sphing-4-enine Stimulated by DTT (PubMed:11463796, PubMed:22860206). Stimulated by nonionic detergent of the polyoxyethylenep-t-octylphenylether type (Triton X-100 or Nonidet P-40) whereas 3-[(3-cholamidopropyl)dimethylammonio]propane-1-sulfonate (CHAPS) and octyl alpha-D-glucopyranoside decrease the N-(long-chain-acyl)ethanolamine deacylase activity (PubMed:22860206). Polysorbate 20 (Tween 20) is inhibitory (PubMed:11463796). Stimulated by endogenous phospholipids such as choline- or ethanolamine-containing phospholipids, and dihydrolipoic acid (PubMed:22860206). Optimum pH is 5 with N-palmitoylethanolamine as substrate. Lipid metabolism; fatty acid metabolism. Heterodimer of an alpha and a beta subunit, produced by autocatalytic cleavage. Expressed in brain, cecum, colon, heart, ileum, kidney, liver, lung, spleen, stomach, submaxillary gland, testis and thymus. N-glycosylated. Tunicamycin treatment causes a reduction in specific activity against N-palmitoylethanolamine. Autoproteolytic cleavage at pH 4.5 gives rise to the alpha and beta subunit. Cleavage gives rise to a conformation change that activates the enzyme. The same catalytic Cys residue mediates the autoproteolytic cleavage and subsequent hydrolysis of lipid substrates. Belongs to the acid ceramidase family.