Biochemical characterization of superoxide dismutase from the roots of Stemona tuberosa

Abstract

Superoxide dismutase (SOD) and bioactive cyclotide were firstly discovered from the root of Stemona tuberosa and the leaves of Viola sumatrana, respectively. Crude protein from S. tuberosa was determined SOD activity and showed the highest SOD activity compared to other ten plants. The crude protein was then performed in two experimental developments. The first experiment is the development of non-denaturing two dimensional gel electrophoresis coupled with SOD staining activity using bovine erythrocyte as a positive control. This technique can be used for the separation of different SOD isozymes. The second experiment was a purification and characterization of SOD from S. tuberosa. The purified SOD (ST-1) which has the highest SOD activity compared to other SODs in this plant was characterized as a purified Mn- SOD. In addition, crude protein from leaves of V. sumatrana was also purified and yielded four bioactive cyclotides. The cyclotides were determined their cytotoxicity on four different human cancer cell lines. The result showed that cyclotide called cycloviolacin O2 showed the most potency on cell cytotoxicity. While, cyclotide called kalata S which lack of secondary structure data then it was identified using NMR experiment. The NMR results showed that the secondary structure of kalata S is similar to kalata B1 which is a Well-known cyclotide using as a drug design application.