Fig. 3

Internalization and cytotoxicity of Tha-PA90 in A549 cells. A Western blot analysis of internalized endolysins. A549 cells were incubated with 0, 1, and 5 μM of Tha-PA90 or PA90. After a 30 min incubation, cells were washed with DPBS to remove external proteins and harvested in 0.05% Triton X-100 solution. Western blotting was performed using an anti-His antibody, with beta-actin as a control. B A549 cells were exposed to 2.5, 5, or 10 μM of Tha-PA90 for 24 h. The cell viability was assessed using the lactate dehydrogenase (LDH) assay. The control group was treated with cell lysis buffer. The experiment was repeated three times. Statistical significance was set at *p < 0.05