DEAE-cellulose (pka 11) at pH7, with a linear salt gradient elution
DEAE is a cationic (amino) group. Hence, the column matrix will have a positive charge below its pK, e.g. at pH=7. (So, it acts as an anion exchange column)
Proteins are retained stronger the more negative they are.
So elution is in this order: 4, 2, 3, 1
Protein 4: pI=9.5, charge: positive
Protein 2: pI=8, charge: positive
Protein 3: pI=5, charge: negative
Protein 1: pI= 4, charge: negative
CM is an anionic (carboxy) group, so it has a negative charge above its pK, e.g. at pH=7.
Proteins are retained stronger the more positive they are.
gel exclusion column
The larger proteins will elute first, within the fractionation range. So:
Protein 3: MW= 64,000
Protein 2: MW= 18,000
Protein 4: MW= 9,000
Protein 1: MW= 2,000