Phosphate-induced protein chromatography.

High phosphate concentration is shown to cause a large proportion of the proteins of a cell-free extract of Escherichia coli to bind to agarose columns to which L-valine is attached. With a decreasing concentration gradient of potassium phosphate, the proteins elute in relation to their solubility in concentrated ammonium sulfate. This column technique appears to provide a general tool for the purification of proteins.