TABLE 2.
MS analysis of the different proteins used in the experiments
T78R144A was not analyzed by MS because it degraded during storage for MS analysis. T44H200A is degraded by 2,627 Da, but it was active in the time course and protein gradient experiments. For this mutant, a C-terminal deletion of 27 amino acids (corresponding to residues 1–353) has a predicted Mr of 41,256.9, which is close to the observed Mr by MS analysis. Other than these two samples, the molecular weights of all of the mutants are in excellent agreement with the expected values.
| Name | Mr from MS | Difference in Mr compared with WT | Expected difference in Mr |
|---|---|---|---|
| T44wt | 43,884.09 | ||
| T44R131A | 43,799.11 | 85 | 85 |
| T44R131K | 43,856 | 28 | 28 |
| T44H200R | 43,903 | 19 | 19 |
| T44H200A | 41,257.14 | −2626.95 | 66.05 |
| T44H200Q | 43,875 | 9 | 9 |
| T44H200N | 43,861 | 23 | 23 |
| T44H200E | 43,876.16 | 8 | 8 |
| T44E215A | 43,826.04 | 58 | 58 |
| T44E215R | 43,911.21 | 27 | 27 |
| T44E215Q | 43,883.3 | 1 | 1 |
| T44E215H | 43,892.25 | 8 | 8 |
| T44K218R | 43,918.83 | 34.74 | 16 |
| T44Y226F | 43,868.01 | 16 | 16 |
| T78wt | 78,426.66 | ||
| T78R131A | 78,341.19 | 85.47 | 85.11 |
| T78H200A | 78,360.45 | 66.21 | 66.16 |
| T78H200R | 78,445.84 | 19.18 | 19.04 |
| T78H200N | 78,403.75 | 22.91 | 23.04 |
| T78H200E | 78,419.36 | 7.3 | 8.03 |
| T78E215A | 78,368.26 | 58.4 | 58.03 |
| T78E215Q | 78,426.52 | 0.14 | 0.99 |
| T78E215L | 78,410.34 | 16.32 | 15.96 |
| T78E215H | 78,434.35 | 7.69 | 8.02 |
| T78K218A | 78,368.9 | 57.76 | 57.19 |
| T78K218E | 78,427.67 | 1.01 | 0.94 |
| T78K218R | 78,454.73 | 28.07 | 28.01 |
| T78Y226F | 78,410.26 | 16.4 | 16 |