Protease inhibitory activity profile of Indonesia wild swamp eel (Monopterus albus)

Abstract

A protease inhibitor is a compound that potentially could inhibit the activity of a protease or some protease enzymes. It has a significant role in fish processing to prevent quality deterioration. The study aimed to investigate the inhibitory activity of wild swamp eel (Monopterus albus) plasma fractionated with ethanol to papain enzyme. The parameters analyzed were protein content, inhibitory activity to papain enzyme, and sodium dodecyl sulphate-polyacrylamide gel electrophoresis to demonstrate the protein profile. The result showed that the amount of protein in the plasma fractionated with ethanol was decreased. The effectiveness in inhibiting papain enzyme was increased when compared to that of the crude plasma, from 65 to 128.56% per mg protein. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that the protein complex alpha-2-macroglobulin in wild swamp eel plasma consists of two different subunits of 120 kDa and 110 kDa. This study suggested that plasma fractionated with ethanol showed inhibitory activity to papain enzyme greater than that of the crude plasma.