Question

2.What would be the effect (if any) on our ion exchange batch purification of a-galactosidase that is performed at pH 7.5 if: (2 points)

1. The ionic capacity of the gel was increased?
2. The pore size of the gel was decreased?
3. The gel was changed to a strong anion exchanger?
4. The gel was changed to a cation exchange gel?

alpha galactosidase

Answer 1

The isoelectric point (pl) is the pH at which a particular protein is overall electrically neutral - in other words the number of positive charge is equal to the number of negative charges.Above its pl,the protein will bind to anion exchanger; below its pl it will bind to cationic exchanger. The pl of alpha - galactosidase is 4.6. Here the purification is performed at pH 7.5 , above 4.6 alpha - galactosudase carries net negative charge and would bind to a anion exchanger, therefor the gel was changed to a strong anionic exchanger

option C is correct.