Biochemical characterisation of an aminopeptidase with highest preference for lysine from Japanese flounder skeletal muscle

► A novel lysine aminopeptidase was purified with high efficiency and yield. ► The enzyme preferred to hydrolyse Lys-MCA. ► MALDI-TOF/TOF-MS/MS was used to identify the purified enzyme. ► The kinetic constants of the enzyme were evaluated. ► The purified enzyme was distinct from other aminopeptidases reported.