FIG. 2.

Effect of inhibitors on extracellular proteases. Lane 1, 5 μl of the supernatant from the Sterne strain grown in NSM at 37°C and harvested as described for lane 4, Fig. 1; lane 2, addition of EGTA to a concentration of 2.5 mM prior to loading; lane 3, 2.5 mM PMSF; lane 4, 2.5 mM O-phenanthroline; lane 5, 2.5 mM E64. A molecular weight marker was a metalloprotease of 36 kDa from B. polymyxa (Sigma P-6141) which migrated a little bit more slowly than band E (Fig. 5).