Mike has determined that enzyme he is attempting to purify has an isoelectric point of 4.5 (pI = 4.5). He has decided to examine anion exchange chromatography as a potential purification step. He...

Mike has determined that enzyme he is attempting to purify has an isoelectric point of 4.5 (pI = 4.5). He has decided to examine anion exchange chromatography as a potential purification step. He tested out using 2 different buffer and linear NaCl gradient on HPLC (like what you did). His results are shown below.

Which buffer should Mike uses for his purification (both buffer has pH higher than enzyme’s pI)? Why?

Extracted text: pH 5 data 2.5 2 -A280 1.5 Enzyme activity 1 0.5 1 3 4 5 7 9 10111315171920212325272930 Fraction number


Extracted text: pH 8 data 2.5 A280 1.5 Enzyme activity 0.5 1 3 4 5 7 9 10111315171920212325272930 Fraction number 2.