FIG. 1.

Purification of PspA. The left-hand panel illustrates the steps in the purification of His₆-PspA as described in Materials and Methods. Portions of each step in the purification were analyzed by sodium dodecyl sulfate–10% polyacrylamide gel electrophoresis and stained with Coomassie brilliant blue. Lanes (percentages in parentheses are the portions of the step that were loaded): M, markers (from the bottom, 21, 30, 46, 66, and 97.4 kDa); P, preinduction K1462.pJD43; I, postinduction K1462.pJD43 (0.06%); S1, soluble fraction (0.1%); S2, soluble fraction following solubilization of the pellet with CHAPS-NaCl (0.1%); FT, flowthrough from the gravity column (0.1%); W, 10 mM imidazole wash (0.2%). The right-hand panel shows fractions from the elution with 100 mM imidazole in order of elution (2% of each fraction was loaded).