Fig. 5

Purification of proteins from the fat body of silkworms with MNP3. a Principle of MNP purification. MNPs bind to target proteins, both are separated from impurities via a magnet, and the supernatant is discarded. After removing the magnet, the target protein-bound MNPs are resuspended (e.g., in elution buffer). b Western blot and CBB-stained membrane of His-tagged mCherry protein purified using MNP3. The elution was performed with 50 µl of 1 mol/l imidazole. The sample was diluted in a volume of 8 µl to 22 µl, and in each lane, 15 µl was loaded. c Optimized and scaled-up (1 ml sample) purification of proteins from the fat body of the silkworm with MNP3 shown by Coomassie blue-stained SDS-PAGE (c) and western blotting results (d) of VP1 purification using MNP3. For both, the washing buffer contained 20 mmol/l imidazole, with 1 ml fat body and 7.5 mg MNPs. The first elution was performed with 300 mmol/l, and the second and third elution was performed with 1 mol/l imidazole (500 µl each). An 8 µl to 22 µl dilution was performed, and 15 µl was loaded in each lane FB: Fat body; FT: Flow-through; W1: 1st Washing fraction; W2: 2nd Washing fraction; E1: 1st Elution fraction; E2: 2nd Elution fraction; MNP: MNPs; M: Marker; Black arrow indicates the target protein