High‐capacity purification of hen egg‐white proteins by ion‐exchange electrochromatography with an oscillatory transverse electric field

Abstract

Original PaperHigh-capacity purification of hen egg-white proteins by ion-exchange electrochromatography with an oscillatory transverse electric fieldThe ion-exchange electrochromatography with an oscillatory electric field perpendicular to the mobile-phase flow driven by pressure (pIEEC) was used to separate hen egg-white (HEW) proteins. The results were compared with those of normal ionexchange chromatography (IEC). The column was designed as three-compartment rectangular column of 2-mL with dimensions (length6width6depth) of 4061065 mm 3 and the electric field was applied across the direction of column width. Q Sepharose FF was packed into the central compartment as the chromatographic bed. It was confirmed that the dynamic binding capacity (DBC) of different proteins (ovotransferrin and ovalbumin) in the HEW solution increased 2.3 times when an oscillatory electric current of 30 mA at 1/20 Hz was applied in the transverse column direction. Then, the HEW proteins were separated by the pIEEC at loading amounts 2.3-fold higher than those by the IEC. When the feedstock of about one-third of the DBC was applied to the columns (i. e., 7 mL for the pIEEC and 3 mL for the IEC), similar separation efficiencies of the two chromatographic modes were achieved. Both the recovery yield and purity reached 73% to over 90%. The results indicate that the pIEEC is promising for high-capacity purification of proteins.

Protein adsorption‐dependent electro‐kinetic pore flow: Modeling of ion‐exchange electrochromatography with an oscillatory transverse electric field

“…3, good model fitting to the breakthrough curves of BSA in the pIEEC was obtained with Eq. (10). This demonstrates the reasonability of the above analysis and Eq.…”

“…However, the driving effect decreases due to the decrease of the Peclet number as depicted by Eq. (10). So, the deviation of BSA distribution also decreases with increasing adsorption time (Fig.…”

“…Three-compartment chromatographic column used in this paper had similar architecture with that described earlier [7][8][9][10]. In such a column, chromatographic bead was packed in central compartment with a dimension of 40 Â 7 Â 7 mm 3 (packed-bed volume, 2.0 mL) while cooled electrode solution (81C) flowed upward its neighboring electrode compartments.…”

“…Moreover, the relatively short distance across the column width permits the generation of large EF strength at a low voltage application. The column design was also proved effective in ion-exchange electrochromatography by its DBC enhancement with increasing EF strength [9], and highcapacity purification of hen egg-white proteins was fulfilled [10]. It is considered that electro-kinetic migrations of protein molecules, including EOF and electrophoresis (EP), contribute to the increased DBC in the IEC with an oscillatory transverse electric field perpendicular to the mobile-phase flow (pIEEC).…”

Effect of electric field on the partitioning behavior of solutes in entropic interaction chromatography

“…HETP values for all solutes in the EC 5/10 column were similar to their corresponding values in the commercial HR 5/10 column, suggesting that both columns had equivalent separation efficiencies. In a chromatographic column with a rectangular cross‐section, EF always led to higher aggregation of the liquid‐phase flow and increased HETP values . In a theoretical way, Khirevich et al also demonstrated that the chromatographic performance depended critically on the column geometry in a (micro)channel packed with particles, and flow profiles of non‐cylindrical columns deviated greatly from those of cylindrical columns .…”