TABLE 4.
Summary of experimental SAXS values
The theoretical radius of gyration (Rg) was calculated using HydroPro (36) using atomic coordinates from docking into ab initio SAXS shape reconstructions. Experimental Rg values were derived from the Guinier plot using AutoRg (27). The maximum particle diameter (Dmax) was calculated using GNOM, and the Porod volume of the hydrated particle (Volume) was calculated as described (30). The apparent molecular weight was estimated from Porod volume/1.7. Theoretical molecular weights of monomeric and 1:1 species are given in parentheses. Twenty low resolution shape reconstructions were derived from the experimental data using ab initio modeling and the mean normalized spatial discrepancy (NSD), used to quantify the agreement between individual reconstructions (35). The χ2 for the fit of the best model to the experimental data is shown.
| Rg (theoretical) | Rg | Dmax | Volume | MWapp | Reconstructions NSD | χ2 | |
|---|---|---|---|---|---|---|---|
| nm | nm | nm | nm3 | ||||
| IT4VAR13DBLβ (45 kDa) | 2.6 | 2.97 ± 0.02 | 12.5 | 106.0 | 62.3 | 0.46 ± 0.03 | 2.7 |
| IT4VAR13DBLβ-ICAM-1D1D2 (70 kDa) | 3.1 | 3.41 ± 0.01 | 12.0 | 141.4 | 83.2 | 0.55 ± 0.02 | 4.4 |
| IT4VAR13DBLβ-ICAM-1D1D5 (95 kDa) | 4.0 | 4.21 ± 0.00 | 18.5 | 154.9 | 91.1 | 0.68 ± 0.04 | 4.6 |
| IT4VAR13 (314 kDa) | 8.1 | 8.1 ± 0.00 | 27.5 | 556.3 | 327.2 | 0.78 ± 0.06 | 1.3 |
| IT4VAR13- ICAM-1D1D5 (364 kDa) | 8.3 | 8.6 ± 0.00 | 26.5 | 649.4 | 382.0 | 1.06 ± 0.03 | 3.7 |