What property of the protein was used to purify out the protein in chromatography column?

What property of the protein was used to purify out the protein in chromatography column?

• A. Hydrophobicity.
• B. Charge.
• C. Size.
• D. Specific binding affinity.

Answer: (A)

Proteins differ in how hydrophobic their surfaces are, and a column that exploits hydrophobic interactions uses this property to separate them. In hydrophobic interaction chromatography, resin bears hydrophobic groups, and in high salt the hydrophobic patches on a protein interact more strongly with the resin. Proteins with greater surface hydrophobicity bind more tightly, while more hydrophilic proteins pass through or elute earlier. By gradually changing salt concentration or solvent conditions, you disrupt those hydrophobic interactions to elute the proteins, achieving purification based on hydrophobicity. Other chromatography modes rely on different properties: charge (ion-exchange), size (size-exclusion), or a specific binding interaction (affinity chromatography). But when the column is designed to separate by hydrophobic interactions, hydrophobicity is the property being exploited.

Proteins differ in how hydrophobic their surfaces are, and a column that exploits hydrophobic interactions uses this property to separate them. In hydrophobic interaction chromatography, resin bears hydrophobic groups, and in high salt the hydrophobic patches on a protein interact more strongly with the resin. Proteins with greater surface hydrophobicity bind more tightly, while more hydrophilic proteins pass through or elute earlier. By gradually changing salt concentration or solvent conditions, you disrupt those hydrophobic interactions to elute the proteins, achieving purification based on hydrophobicity.

Other chromatography modes rely on different properties: charge (ion-exchange), size (size-exclusion), or a specific binding interaction (affinity chromatography). But when the column is designed to separate by hydrophobic interactions, hydrophobicity is the property being exploited.