Table 2.
Biological activity of toxin reconstituted with the mutated Cdt subunits
| Subunit composition of the Cdt | % of CHO cells that were diploid in: |
CHO cell proliferationa (% of surviving CFU) | |||
|---|---|---|---|---|---|
| G1 (2N DNA content) | G2 (4N DNA content) | S | G2/G1 | ||
| None | 65.48 | 14.84 | 19.68 | 0.23 | 100 ± 5 |
| CdtABC | 30.36 | 53.10 | 16.46 | 1.75 | 0 |
| CdtABH160AC | 78.40 | 0.02 | 21.58 | 0 | 99 ± 2 |
| CdtALumBC | 27.01 | 48.34 | 24.65 | 1.79 | 8 ± 14 |
| CdtABLumC | 19.51 | 63.96 | 16.53 | 3.27 | 10 ± 10 |
| CdtABCLum | 17.45 | 66.85 | 15.70 | 3.83 | 5 ± 6 |
| CdtALum, Y214ABC | 48.90 | 26.37 | 24.73 | 0.54 | 70 ± 9 |
| CdtABLum, CH-1 | 77.71 | 3.77 | 18.53 | 0.05 | 98 ± 1 |
| CdtABLum, A9-3C | 55.76 | 22.41 | 21.83 | 0.41 | 96 ± 3 |
| CdtABLum, A10-2C | 60.62 | 19.72 | 19.67 | 0.33 | 100 ± 6 |
| CdtABLum, NLS1C | 42.11 | 34.97 | 22.92 | 0.83 | 6 ± 5 |
| CdtABLum, NLS2C | 45.99 | 35.44 | 18.57 | 0.77 | 83 ± 5 |
| CdtABCLum, R1 | 46.12 | 28.48 | 25.40 | 0.62 | 0 |
| CdtABCLum, R2 | 42.46 | 31.82 | 25.72 | 0.75 | 5 ± 27 |
| CdtABCLum, AT | 75.68 | 1.84 | 22.49 | 0.02 | 95 ± 2 |
| None + MβCD | 48.24 | 17.72 | 34.04 | 0.37 | ND |
| CdtABC + MβCD | 57.36 | 0 | 42.64 | 0 | ND |
a
CHO cells (350 cells/well) exposed to 5 μg/ml of total Cdt protein. Cells were counted as CFU. ND, not determined.