Fig. 1

Expression and purification of rFimA. (a) rFimA expression was induced in E. coli BL21 competent cells by transformation with the DNA plasmid PYT1245 using the heat shock method. (b) Ampicillin-resistance transformants were induced by Isopropyl-β-D-thiogalactopyranoside (IPTG), and disrupted with ultrasonication. The supernatants from ultrasonicated E. coli BL21 containing Glutathione S-transferase (GST)-rFimA fusion proteins were applied to a GST affinity column. rFimA protein was eluted by cleaving the GST domain from rFimA using PreScission Protease. The purified rFimA protein was electrophoresed in a 4–20% gradient SDS-PAGE gel and stained with Coomassie brilliant blue R-250. Lane 1: standard marker, Lane 2: the supernatants from the ultrasonicated transformant, Lane 3: eluted solution (1 μg) from GST affinity column, Lane 4: eluted solution (3 μg) from the GST affinity column. (c) The purity of rFimA was confirmed by western blot analysis. rFimA (5 μg) was transferred to a PVDF membrane and detected using rabbit anti-fimbriae serum (1: 2000 dilution) followed by HRP-conjugated goat anti-rabbit IgG Ab and TMB substrate solution. Lane 1; protein molecular weight marker, Lane 2; purified rFimA