[erv10s]

After collecting fractions from a cation exchange chromatography column, why would the fractions first be adjusted to pH 7 before an assay of the protein activity is conducted?


I was thinking that adjusting to neutral pH would ensure that the protein does not denature so that an accurate measurement of protein activity can be made.

Thanks.

[Yggdrasil]

Yes.  In addition, the activity of some proteins will be highly sensitive to pH because they require the protonation/deprotonation of certain residues that are involved in catalysis.