The Protease Inhibitor Cocktail Set Ⅲ DMSO Solution (EDTA Free), 4-(2-Aminoethyl) benzenesulfonyl fluoride hydrochloride (AEBSF), aprotinin bovine lung, and leupeptin hemisulfate monohydrate were obtained from Wako. The stocks were dissolved in water. Bestatin and pepstatin A were also obtained from FUJIFILM Wako Pure Chemical Corporation, and the stocks were dissolved in DMSO. E-64 was obtained from Sigma-Aldrich, and the stock was dissolved in water. Each protease was used with the following final concentration : AEBSF 1 mmol / L, aprotinin bovine lung 0.8 µmol / L, E-64 15 µmol / L, leupeptin hemisulfate 20 µmol / L, Bestatin 50 µmol / L, pepstatin A 10 µmol / L.