Suppose that you are given a mixture of proteins that you analyze by standard 2-D electrophoresis, with the following results for isoelectric points and apparent molecular weights: protein A (Mr 34,325; pI 7.82), protein B (Mr 65,605; pI 5.44), and protein C (Mr 104,271; pI 6.54).
a. In the isoelectric focusing, in what order did the proteins band, starting with the anode and going to the cathode? Explain why.
b. If the mixture is subjected to Phospho-matrix chromatography, what pH range should you use for the buffer and in what order will the proteins emerge from the column? Explain why.