[Purification and biochemical character of a fibrinolytic protein from Eupolyphaga sinensis].

A novel of fibrinolytic protein has been separated and purified by ammonium sulfate fractionation, DEAE-cellulose and SephadexG-75 Column chromatography from the tissue of the female Eupolyphaga sinensis in the paper. The protein showed an apparent molecular weight of 41.3 kD on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. In addition, it includes 10.5% sugar. Its specific activity to hydrolyze fibrin was 547.86 u/mg. The enzyme activity was inhibited by Mg2+, Ca2+, protein inhibitors, such as 8mol/L urea and 1% beta-mercaptoethanol, and serine protease inhibitor such as phenylmethanesulfonyl fluoride (PMSF), but wasn't inhibited by Na+, K+ and ethylenediaminotetraacetic acid (EDTA). The protein was stable under 40 degrees C and it's optimal temperature was also 40 degrees C. It's optimal pH was 8.0. It showed a different way between the activity and UK when they degrade the plasminogen. Based on all the messages the protein can be suggested to be a novel fibrinolytic protein. There have been no such component of fiberinolytic enzyme from Eupolyphaga sinensis walker reported yet.