Abstract
We have been surveying plant-proteases that could be used as an effective decomposer of the surplus protein in environment. If plants have SDS resistant proteases, they would show poor profiles in SDS-PAGE. The plant showing the least number of polypeptide bands in tested plants was the white skunk cabbage (Lysichiton camtschatcense). The protease activity of the leaf extract was determined by measuring the digestion of BSA. A higher concentration of the reducing agent was necessary to keep the protease activity in the extract. The protease showed maximum activity in the presence of 0.1% SDS and 0.5% mercaptoethanol, and about 40% of the activity was remained even in 2% SDS. The pH profile with bell shape showed a peak at pH 7.5. The molecular size was estimated as about 28 kDa. It is concluded by the sensitivity to inhibitors that this protease is a cysteine endoprotease.
