Purification of soluble FGF19 and TRXtFGF19 proteins from <i>E. coli</i> cytosol lysates.

<p>Purification of soluble FGF19 (A) and TRXtFGF19 (B) from cell lysates by Ni-NTA affinity chromatography with AKTA FPLC system. Lane 1: protein markers; Lane 2: lysate (soluble fraction); Lane 3: flow through; Lane 4 to 15: elution fractions. (C) The second cycle of cation exchange chromatography (HiTrap Q column) of elution peak pool from IMAC column. Lane 1: Molecular weight. Lane 2 to 9: fractions contain purified FGF19 (left panel) and TRXtFGF19 (right panel). (D) Purification of TEV protease produced from BL21(DE3) strain by IMAC chromatography with AKTA FPLC system. Lane 1: protein markers; Lane 2: Soluble fraction of total cell lysate; Lane 3: Ni-NTA column flow-through; Lane 4: purified TEV protease; Lane 5: purified TRXtFGF19; Lane 6: TRXtFGF19 protein after TEV protease digestion. Arrow indicates the protein size according to their predicted molecular weight.