Figure 5
From: Zinc–induced envelope stress diminishes type III secretion in enteropathogenic Escherichia coli
Zinc and ammonium metavanadate both inhibit protein secretion from EPEC. Cultures of EPEC strain E2348/69 were grown statically overnight in DMEM with varied concentrations of zinc acetate or ammonium metavanadate to an OD600 of 0.8 - 1.0. A culture of an EPEC strain deficient in type III secretion (ΔescN) was included as a control. Cells were removed by centrifugation, then proteins in the culture medium were precipitated with 25% trichloroacetic acid and visualized with SDS-PAGE. The volume of supernatant precipitated was chosen such that volume (ml)×culture OD600 = 6.0.