The acidic protease was purified from 4-day cultivation of Aspergillus oryzae BCRC 30118 by DEAE Sephacel and Sephacryl S-200 HR chromatographs. The specific activity, yield and purification fold were 117.62 kU/mg, 15.1% and 6.6, respectively. The molecular weight (M) was 41.0 kDa, while the optimal pH and temperature were 3.0 and 60°C, respectively. It was stable at pH 3.0-6.0 and 4-35°C. However, it was inhibited by Fe2+, Hg2+, Fe3+ and pepstatin A, and slightly by leupeptin and TPCK. According to substrate specificity and inhibitor study, it was a cysteine protease with activation energy of 37.5 kcal/mol. Its Km, Vmax, Kcat and Kcat/Km for the hydrolysis of hemoglobin were 0.12 mM, 14.29 µmol/min, 14.55 sec-1 and 125.80 (sec-1 mM-1), respectively
Yin, Li-Jung; Chou, Ya-Hui; and Jiang, Shann-Tzong
"PURIFICATION AND CHARACTERIZATION OF ACIDIC PROTEASE FROM ASPERGILLUS ORYZAE BCRC 30118,"
Journal of Marine Science and Technology: Vol. 21:
1, Article 14.
Available at: https://jmstt.ntou.edu.tw/journal/vol21/iss1/14