TABLE 1.
Biological activities of mutant HNs
| HN | Expressiona | HADb | NAb | Fusionc |
|---|---|---|---|---|
| WT | 100.0 | 100.0 | 100.0 | 22.1 ± 4.0 |
| Mutants | ||||
| G169A | 107.1 ± 27.8 | 87.9 ± 20.0 | 79.1 ± 9.1 | 36.0 ± 2.7 |
| T216A | 93.7 ± 6.3 | 53.6 ± 9.7 | 122.7 ± 8.2 | 1.9 ± 1.8 |
| T232A | 98.5 ± 0.2 | 113.3 ± 8.3 | 78.4 ± 14.1 | 15.6 ± 2.3 |
| Q280A | 107.7 ± 3.5 | 95.5 ± 10.7 | 87.6 ± 8.0 | 20.4 ± 3.3 |
| T289A | 114.8 ± 9.9 | 103.7 ± 13.0 | 99.7 ± 2.8 | 19.5 ± 2.1 |
| G332A | 103.1 ± 17.1 | 109.1 ± 21.3 | 92.8 ± 13.6 | 21.3 ± 3.1 |
| I336A | 104.3 ± 12.2 | 93.5 ± 18.8 | 107.1 ± 7.6 | 20.4 ± 5.5 |
| E384A | 118.1 ± 24.3 | 88.1 ± 5.9 | 99.0 ± 5.8 | 20.8 ± 2.9 |
| E495A | 113.4 ± 3.9 | 117.3 ± 19.6 | 113.4 ± 9.2 | 22.9 ± 3.0 |
| S518A | 136.2 ± 19.4 | 101.7 ± 18.6 | 79.9 ± 3.5 | 16.7 ± 2.2 |
| F553A | 93.7 ± 25.9 | 28.0 ± 3.1 | 30.3 ± 5.8 | 2.6 ± 1.1 |
| R557A | 91.4 ± 12.8 | 22.5 ± 1.5 | 80.9 ± 10.2 | 1.0 ± 0.9 |
| E158A | 69.7 ± 12.2 | 48.4 ± 16.1 | 116.7 ± 5.1 | 1.7 ± 0.8 |
| L160A | 84.5 ± 14.9 | 20.3 ± 8.4 | 129.7 ± 11.0 | 2.8 ± 0.2 |
| F220A | 79.7 ± 2.9 | 21.8 ± 5.8 | 87.2 ± 16.8 | 2.1 ± 1.3 |
| L224A | 74.3 ± 12.6 | 67.6 ± 13.4 | 102.9 ± 11.3 | 2.4 ± 1.6 |
| K536A | 69.2 ± 7.7 | 77.4 ± 6.0 | 85.9 ± 3.1 | 3.6 ± 1.6 |
a
Cell surface expression levels of mutant HNs related to those of wild-type HN. The values are averages ± standard deviations of three independent experiments.
b
HAD and NA activities of mutant HNs are expressed as normalized percentage values relative to the amount of HN expressed at the cell surface. Each value is a percentage of the activity of wild-type NDV HN. All values are averages ± standard deviations of three independent experiments.
c
Fusion promotion activity of mutant HN. Cell fusion was calculated as the ratio of the total number of nuclei in multinuclear cells to the total number of nuclei in the field (7). The values are averages ± standard deviations of three independent experiments.