Expression and purification of TAT-NPM fusion proteins. (A) Schematic presentation of TAT-NPM fusions. (B) Expression of TAT-NPM fusions. E coli BL21 cells harboring vector (TAT), TAT-NPMΔN, TAT-NPMΔC, or TAT-NPM were grown in the presence (+) of Isopropyl-β-D-1-thiogalactopyranoside (IPTG) to induce expression of the TAT-fusion proteins. 50 μg cell lysates were analyzed by Coomassie blue staining. Arrows denote the corresponding TAT-fusion proteins. (C) Western blot analysis of the TAT-NPM proteins using an anti-histidine antibody. TAT-NPM fusion proteins were purified by affinity chromatography on a Nickel-sepharose column, followed by gel filtration on a PD-10 column.