In ion-exchange chromatography, which type of resin attracts positively charged proteins?

The DEAE resin is anion exchange resin that contains positively charged groups, allowing it to attract and bind negatively charged proteins. In the context of ion-exchange chromatography, positively charged proteins will interact with negatively charged groups on the resin.

To elaborate, the underlying principle of ion-exchange chromatography relies on the charge characteristics of the molecules being separated. Proteins are made up of amino acids, which have varying charges at a given pH. When using DEAE resin, which contains diethylaminoethyl groups, it can effectively bind negatively charged proteins at a specific pH. This binding is facilitated by electrostatic interactions.

This type of chromatography enables the separation and purification of proteins based on their net charge, which varies with the pH of the buffer solution used during the process. The correct identification of such resins is crucial for successful protein purification protocols, and recognizing the role of charged groups is fundamental in understanding how ion-exchange chromatography operates.

In contrast, the other types of resins mentioned either operate on different principles (such as the size-exclusion resin, which separates based on size) or are involved in attracting other charged molecules, such as CM resin, which attracts positively charged proteins due to its negatively charged surface.