DEVELOPMENT OF ISOLATION METHOD OF WHITE RADISH PEROXIDASE (WRP): THE EFFECT OF MOLECULAR WEIGHT AND CONCENTRATION OF POLYETHYLENE GLYCOL ON PEROXIDASE PRECIPITATION

• Main Author: Apriliani, Iin
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/41827
• Institution: Institut Teknologi Bandung

Peroxidase is an important enzyme in diagnostics. The enzyme plays a critical role in color reaction to determine the presence of an analyte in samples. Commercial peroxidase is currently isolated from horseradish roots which is widely grown in sub-tropical countries. Other plants that has a great potential as a source of peroxidase in tropical countries is white radish. The horticultural plant originated from China and widely spread to various countries including Indonesia which is generally used as food or traditional medicine. A number of research has found that white radish has the highest peroxidase content among the other members of Brasiccaceae family. This research was conducted to determine the effect of PEG molecular weight and concentration on peroxidase precipitation out of white radish extracts. In this research three types of PEG were used (PEG 400, 4000 and 6000), each with concentrations of 20%, 40%, 60% and 80%. The results show that PEG 400 has a low ability to precipitate peroxidase and protein component in the extracts of white radish and peroxidase tends to be in supernatant. Furthermore, it was found that PEG 4000 and 6000 has a greater ability to precipitate peroxidase and protein components in the extracts of white radish with a lower concentration compared to the PEG 400, precipitation with PEG 4000 and 6000 produces peroxidase that tend to be at pellet. Based on the results of this experiment, the isolation method was designed with several combinations of PEG 400 and PEG 6000 and the result shows that isolation of peroxidase using a combination of PEG 400 20% + 6000 30% produce peroxidase with the highest specific activity compared to the other combination.