Explain how a change in pH can be used to partially purify a

Explain how a change in pH can be used to partially purify a protein from a crude protein extract. Explain why molecular sieve chromatography can be used to reduce the salt concentration of a protein solution.

Solution

33. Proteins can be eluted from the crude protein extract by changing the ph.

It aimsto decrease the net absolute value of the charges of absorbed protein, decreases their attractions to stationary phase, hence acclerating their elution process.

This occurs in ion exchange chromatographic method

At a ph more than PI , protein becomes negatively charged, at ph less than PI it becomes positively charged .

PI is isoelectric point