Question

2. Based on the pI of OleT, estimate a suitable pH range for buffers to be used for purification of OleT via anion exchange chromatography. (1 pt)

Answer 1

The pI of the protein we have gives us an idea about the net charge only. In the process of ion-exchange, surface charge of the protein we have is of more concern. Initially we can try any one from Q, Capto-Q or Nuvia Q (as all are strong anion exchangers) at different pH (we can select a range depending upon our interest of focus where our protein remains active) and see at which pH it is binding to the beads/resin. Alternatively we can also load the flow through (in case protein does not bind to previous column) on to S650 (Cation exchanger) and look for its binding.Once it's pH and resin are found then we can purify it.