Neisseria gonorrhoeae employs two protein inhibitors to evade killing by human lysozyme
A. WT Gc was exposed to the indicated concentrations of lysozyme for 3 hr (see Materials and methods). Gc survival was determined as in Fig 2B. n = 3 biological replicates. Values are represented as the mean ± SEM. B. 1063(WT)-FLAG native or WT Gc were exposed to vehicle or lysozyme at indicated concentrations for 3 hr before harvesting protein. Blots were probed with anti-FLAG antibody, and then stripped and reprobed with anti-Zwf antibody as a loading control. Shown is 1 representative immunoblot of 6 biological replicates. C. The density of Ng_1063-FLAG and Zwf bands were quantified using ImageJ. For each treatment, the ratio of Ng_1063-FLAG to Zwf density was determined and expressed relative to the matched vehicle-treated samples in that experiment (set to an arbitrary value of 1). Each biological replicate is indicated by a different colored circle. Data are shown as mean ± SEM. *p < 0.05; two tailed t-test, n = 6 biological replicates from 2 independent experiments. D. WT or Δ1981 Gc were exposed to lysozyme and processed as in Fig. 4B. Blots were probed with anti-r1981 antisera, and then stripped and reprobed with anti-Zwf antibody as a loading control. Shown is 1 representative immunoblot of 12 biological replicates. E. Relative densities of Ng_1981 and Zwf protein were determined and presented as in Fig. 4C. *p < 0.05; two tailed t-test, n = 12 biological replicates from 4 independent experiments.