Use of different affinity media for purification of DspB.
| Protein source | Protein recovery (mg g−1 Ni-MNPs or Ni-NTA) | DspB activity recovery (U g−1 Ni-MNPs or Ni-NTA) | DspB activitya (U mg−1) | DspB purityb (%) |
|---|---|---|---|---|
| 0.5 mL cell lysatec | 0.71 ± 0.01 (mg) | 0.192 ± 0.004 (U) | 0.27 ± 0.01 | — |
| Ni-FS-TED | 8.37 ± 0.49 | 6.35 ± 0.16 | 0.76 ± 0.04 | 94.3 |
| Ni-FS-IDA | 35.76 ± 1.68 | 28.51 ± 0.88 | 0.80 ± 0.02 | 92.7 |
| Ni-FS-ECH-IDA | 35.61 ± 2.38 | 27.60 ± 0.47 | 0.78 ± 0.05 | 91.2 |
| Commercial Ni-NTA | 36.26 ± 1.68 | 25.25 ± 0.49 | 0.70 ± 0.02 | 85.5 |
a
DspB activity (U mg−1) = DspB activity recovery (U g−1)/protein recovery (mg g−1).
b
DspB purity was determined by densitometric scanning of SDS-PAGE gel.
c
Total amount of proteins (mg) or DspB activity (U) from 0.5 cell lysate was assayed and used for comparison.