A protease which was responsible for infectivity of human Influenza virus was partially purified from the amniotic fluid of chicken embryonated eggs inoculated with human influenza virus using synthetic peptide substrate(CBZ-arg-AFC). The
molecular
weight of the protease was estimated to be 55kDa, by determination using gel filtration on Sepharcryl S-200HR.
The optimum pH for enzyme activity was 8.5 and the enzyme was stable at pH from 7.5 to 10.0.
The protease was inhibited by DFP, PMSF, leupeptin and TLCK but not by TPCK, E-64,pepstatin A, and EDTA, indicating that the enzyme is a trypsin-like serine protease.
The purified protease increased the proliferation of virus in-vitro culture on the MDCK cells.
|