Question

When pH of enzyme solution is below their isoelectric point, the enzymes will be negatively charged and bind to anion exchangers.

(a) True

(b) False

I got this question during an interview.

The question is from Enzymes Purification in portion Enzymes Purification of Enzyme Technology

Answer 1

Correct option is (b) False

To explain: Enzymes possess a net charge in solution as they contain both positive and negative charges. Isoelectric point is the pH at which the net charge on the molecule is zero. When pH of the solution is reduced below the isoelectric point, the enzymes will become positively charged and bind cation exchangers. Whereas when the pH is above the isoelectric point the enzymes will become negatively charged and bind to anion exchangers. Hence the above statement is false.