[Detection of protease specifically splitting actin in revertants of Shigella flexneri L-forms]

Proteolytic activity of cell extracts from revertants of Shigella flexneri L-forms as well as biochemical properties of these strains and their sensitivity to antibiotics were studied. The protease found earlier in cells of strain E. coli A2 was shown to be synthesized by one of 8 revertants under study. This protease split actin and did not split some other proteins, its activity was inhibited by inhibitors of metalloproteases. Strain 5a2c which produced the protease was similar to the strain E. coli A2 and differed from other revertants in some biochemical properties, resistance to ampicillin and sensitivity to furazolidone. Thus the protease activity can be a marker of structural and functional transformation of Sh. flexneri under the influence of furazolidone.