Table 3.
Step | Volume (mL) | Total protein (mg)a | Yield of fusion protein (%) |
---|---|---|---|
Sonicated cellsb | 50 | 789 | 100 |
Cell-free lysate | 41 | 571 | 72 |
Ni IMAC | 8.5 | 73c | 9.3 |
Determined by Bradford assay [58].
Prepared from 7.8 g of E. coli cells obtained from 2 L of IPTG-induced culture medium.
Yield of His8-MBP-fl-cytb5 fusion protein. A yield of 18 mg of fl-cytb5 (25% of total protein yield) was present in the heme-reconstituted fusion protein as determined by optical spectroscopy. This measurement was consistent with the 26% contribution of fl-cytb5 to the mass of the fusion protein.