Biochem/physiol Actions N-Acetyl-D-leucine is a substrate for D-aminoacylase from Alcaligenes xylosoxydans subsp. xylosoxydans A-6. N-Acetyl-D-leucine is used to help differentiate members of the amidohydrolase enzyme superfamily. It is a preferred substrate of Gox1177 from Gluconobacter oxidans.