Ion Exchange in Escherichia coli: Potassium-Binding Proteins.

The potassium binding that occurs during passive accumulation by intact Escherichia coli has been demonstrated in a cell-free system. The data suggest that this binding is due largely to binding by the cell proteins in general and cannot be accounted for by the binding of a particular protein. The results are in accord with the view that the ion-exchange properties of protoplasmic poly-electrolyte determine the overall ionic composition of the cell.