Fig. 2

Purified recombinant protein, PfkA expressed in E. coli and recovered from the cell-free lysate after being passed through a HisTrap HP column charged with cobalt. Pure protein samples are seen in the lanes labeled Eds (eluted with 100% elution buffer & dialyzed) and E (100% elution buffer). Before elution of desired protein, the column was washed with 15 column volumes of binding buffer, followed by a 5% incremental increase of elution to binding buffer up to 50%. B.—water, X.— cell-free extract, W—binding buffer wash, L— prestained PAGE ruler plus protein ladder, #%- ration of elution to binding buffer in the wash