FIGURE 4.

Gel electrophoresis of LpxE at various stages of the purification. The molecular weight standards, shown in lanes 1 and 7, are 10, 15, 20, 25, 37, 50, 75, 100, 150, and 250 kDa; lane 2, 10 μg of membrane protein from Novablue(DE3)/pET-28a induced with IPTG; lane 3, 10 μg of membrane protein from Novablue(DE3)/pLpxE-4 induced with IPTG; lane 4, 10 μg of 4% Triton X-100-treated LpxE membranes from Novablue(DE3)/pLpxE-4 induced with IPTG (pre-centrifugation); lane 5, 10 μg of 4% Triton X-100-solubilized LpxE membranes (post-centrifugation); lane 6, 10 μg of purified LpxE protein (after the Ni²⁺-NTA column).