Table 4. Determination of masses by ESI–MS.
| Sample | Solution | Species designation | Measured mass (Da) | Calculated average mass* |
|---|---|---|---|---|
| CA | Denaturing | Species ‘A’† | 8563±5 | |
| CA | 29017±10 | 29024 | ||
| Near-native | Species ‘A’ | 8563±5 | ||
| CA+Zn | 29088±15 | 29089 | ||
| CA+Zn+haem | 29700±15 | 29705 | ||
| Recombinant mICA | Denaturing | mICA | 80450±800 | 76512* |
| Near-native | mICA | 80525±800 | 76512* | |
| Recombinant mICA+CA | Denaturing | CA | 29019±10 | 29024 |
| mICA | 80588±800 | 76512* | ||
| Near-native | ZnCA/mICA | 109988±1500 | 105601* |
*The calculated mass of mICA (residues 1–681) is 74793 Da, to which is added 440 Da for the VPDK sequence, 823 Da for the hexahistidine tag and 456 Da for the Factor Xa cleavage sequence for a total mass of 76512 Da. The difference is attributed to the carbohydrate (see the Results and discussion section).
†Unidentified species found in the sample.