Amidase with broad substrate specificity, catalyzing the hydrolysis of a wide range of N-substituted amides, and, to a lesser extent, the hydrolysis of non-substituted amides. Acid para-nitroanilides (4'-nitroacetanilide, Gly-pNA, Ala-pNA, Leu-pNA) are the best substrates for this enzyme. N-substituted acrylamides (isopropyl acrylamide, N,N-dimethyl-aminopropyl acrylamide, and methylene-bis-acrylamide), N-acetyl derivatives of glycine, alanine and leucine, and aliphatic amides (acetamide, acrylamide, isobutyramide, n-butyramide, and valeramide) can also be used as substrates but with less efficiency. a monocarboxylic acid amide + H2O = a monocarboxylate + NH4(+) an anilide + H2O = a carboxylate + aniline + H(+) an N-acyl-L-amino acid + H2O = a carboxylate + an L-alpha-amino acid an N-acetyl-L-cysteine-S-conjugate + H2O = acetate + an S-substituted L-cysteine Amidase activity is completely suppressed by inhibitors of serine proteases (phenylmethylsulfonyl fluoride and diisopropyl fluorophosphate), partially inhibited by copper and mercury ions, but is not affected by inhibitors of aliphatic amidases (acetaldehyde and nitrophenyl disulfides) or by EDTA. Optimum pH is 7-8. At low pH values the enzyme is rapidly inactivated, whereas in basic medium inactivation is rather slow. Optimum temperature is 55 degrees Celsius. Shows a drastic decrease in activity above the optimal temperature. Is stable for 15 hours at 22 degrees Celsius and for 0.5 hour at 45 degrees Celsius. By acetanilide. Belongs to the amidase family.