Figure 3.

Effects of ADP-ribosyl-HNP-1 on HNP-1 antimicrobial and cytotoxic activity. (a) HNP-1 (100 nM) was incubated with the indicated concentration of ADP-ribosyl-HNP-1 before addition to E. coli ATCC 43827 for radial diffusion assay. Difference in zone size was calculated as in Fig. 2 (⧫). Data are means ± SEM of values from three experiments. (b) HNP-1 (12 μM) was incubated with the indicated concentration of ADP-ribosyl-HNP-1 before addition to ⁵¹Cr-labeled A549 cells (⧫). Percentage of cell lysis was determined as in Fig. 2 to compare effects of HNP-1(○) and ADP-ribosyl-HNP-1 (□). Data are means ± 1/2 range of values from two experiments. Results were similar in another experiment by using 24 μM HNP-1.