High Level Expression and Purification of Atl, the Major Autolytic Protein of Staphylococcus aureus

Figure 3

Zymographic detection of the autolytic activity in recombinant His-tagged Atl. Protein extracts from E. coli BL21 cells grown with IPTG were used in this study. The protein extract was separated by 12.5% SDS-gel electrophoresis. The SDS gel was impregnated with autoclaved S. aureus RN450 cells. Autolytic activity was detected by renaturing the autolysins by incubation of the gel in 50 mM Tri-HCl buffer, pH 7.5, containing 0.05% Triton X-100. Lane 1: full length His-tagged Atl; lane 2: Atl-1; lane 3: Atl-2; lane 4: Atl-3; lane 5: Atl-4; lane 6: Atl-5; lane 7: Atl-6; lane 8: Atl-7; lane 9: Atl-8.