1. An enzyme (MW 24 kDa, pI 5.5) is contaminated with two other proteins, one with a similar molecular mass and a pI of 7.0 while the other has a molecular mass of 100 kDa and a pI of 5.4. Suggest a procedure to purify the contaminated enzyme.
2. What is the importance of sequestering of glucokinase in nucleus and why is this process activated by fructose-6-phosphate and not by glucose-6-phosphate?
3. What are the principles and the purpose of using differential salt precipitation in protein purification?