FIG. 1.

Overexpression of the truncated S-layer protein. The cloned truncated S-layer protein was overexpressed in E. coli BL21(DE3)/pLysS. Following induction with 0.4 mM IPTG, 1.5-ml samples were taken at various time points and centrifuged and the pellet was resuspended in 100 μl of 2× ESB and boiled for 5 min. Ten-microliter aliquots were examined by immunoblotting using a primary anti-His antibody at a dilution of 1:20,000. Lanes (from left): 1, immediately prior to IPTG addition; 2 to 8: 0.5, 1, 1.5, 2, 2.5, 3, and 4 h postinduction, respectively; 9, uninduced cells after 4-h mock induction. The corresponding N-terminal sequence determined for each band is indicated.