FIG. 1.

SDS-PAGE (A) and a Western blot, stained with Penta-His antibody (B), of purification of D50 protein (arrowed). Proteins eluted with buffer E, pH 4.8. Lanes: 1, Qiagen His₆ protein ladder; 2, broth culture; 3, column flowthrough; 4, column wash 1; 5, wash 2; 6, column elution 1; 7, elution 2; 8, elution 3; 9, elution 4; 10, elution 5; 11, elution 6; and 12, elution 7. Lower-molecular-weight proteins were present in occasional batches for both C50 and D50 expression. These proteins reacted with both anti-His and anti-BoNT antisera and appear to represent degradation products of the full-length products.