Simultaneous Separation of Cationic and Anionic Proteins Using Zwitterionic Surfactants in Capillary Electrophoresis

Abstract

The zwitterionic surfactant Rewoteric AM CAS U forms a dynamic wall coating that prevents the adsorption of cationic proteins as well as suppresses the electroosmotic flow (EOF). Addition of polarizable anions to buffers containing this zwitterionic surfactant increases the once suppressed EOF to values nearing +3 x 10(-4) cm2/(V s). The retention of the EOF allows for the separation of analytes of widely different mobilities and is demonstrated by the simultaneous separation of cationic and anionic proteins. Using a buffer containing optimal amounts of the polarizable anion perchlorate and surfactant CAS U, the proteins lysozyme, ribonuclease A, alpha-chymotrypsinogen A, and myoglobin are separated in less than 15 min. Efficiencies as high as 1.5 million plates/m and recoveries greater than 91% are observed for proteins injected in distilled water. Migration time reproducibility is approximately 1% RSD within 1 day and approximately 3% RSD from day to day. The anionic and cationic proteins can be separated over a pH range of 5.5-9, all yielding good efficiencies.

Cationized hydroxyethylcellulose as a novel, adsorbed coating for basic protein separation by capillary electrophoresis

“…The peak tails appeared and separation efficiency decreased with decrease in the ionic strength of buffer solution. This result is due to the ionic strength of the buffer plays some role on improving the separation [36,37]. Thus, the high ionic strength buffer solution was selected as the optimal buffer in this experiment.…”

Cationic gemini surfactant as dynamic coating in CE for the control of EOF and wall adsorption

“…Three basic proteins, ribonuclease A, cytochrome c and lysozyme were selected as model proteins due to their strong adsorption on the capillary wall, which results in bad efficiency, low protein recovery, and poor repeatability in migration time in common CE assay [13]. Generally speaking, an ideal coating for protein separation should exhibit high efficiency, good recovery and repeatability, retention of EOF, facility to apply, inexpensive, and availability over a wide range of buffer conditions [28,29]. Thus, we mainly focused on the performance of gemini dynamic coating in these aspects.…”

Weak Binding of N-Alkylpyridinium Ions to Nonionic Surfactant Micelles as Studied by Capillary Zone Electrophoresis

“…[1][2][3][4][5][6] Dansylamino acids 5 and peptides 6 have been resolved with Tween 20 and Brij 35, respectively. The resolution improvement is attributed to the binding of ionic analytes to the nonionic surfactant micelles.…”