Separation behavior of proteins near the isoelectric points in electrostatic interaction (ion exchange) chromatography

摘要

Electrostatic interaction chromatography (EIC) commonly called ion exchange chromatography (IEC) is a very efficient and versatile method for separating and purifying proteins. Among various elution methods linear gradient elution (LGE) is most efficient for purifying a target protein from similar contaminant proteins. It is also useful for obtaining important information needed for understanding separation mechanisms rapidly. In this paper, our proposed method using LGE-IEC was described briefly, and applied to separation of β-lactoglobulin A and B (LgA, LgB) as model proteins. Resolution and retention of proteins in IEC near the isoelectric points (pI) were carefully investigated. The number of binding sites-pH relationships determined from LGE-IEC experiments were analyzed in order to understand good resolution (separation) near the pI.