Extraction, characterization and purification enzymes cathepsin from catfish (Pangasius Hypophthalmus)

Abstract

This study aims to extract the enzyme cathepsin, to characterize the crude extract and to purify the cathepsin enzyme derived from catfish. the stages of this research consists of the extraction, characterization, and purification of the enzyme cathepsin. the characteristic of crude extract from cathepsin enzyme is that it has temperature, pH and substrate optimum around 50 °C, 6, and 2%. The presence of Fe3+ , Cu2+, Ca2+,Mn2+ metal ions can inhibit enzyme activity. Purification process using ion exchange chromatography on DEAE-sephadex A- 50 gives the best value on the activity of the fraction 18 is equal to 0.762 U / mL and the specific activity of 54.077 mg / mL as well as having multiple levels of purification of 59.602 times. Molecular weight of cathepsin enzyme is purely the result of SDS-PAGE and the molecular weight of 43.18 kDa enzyme has a proteolytic activity alleged in zimogram analysis is 49.93 kDa.