Lysine-based zwitterionic molecular micelle for simultaneous separation of acidic and basic proteins using open tubular capillary electrochromatography.

In this work, a zwitterionic molecular micelle, poly-epsilon-sodium-undecanoyl lysinate (poly-epsilon-SUK), was synthesized and employed as a coating in open tubular capillary electrochromatography (OT-CEC) for protein separation. The zwitterionic poly-epsilon-SUK containing both carboxylic acid and amine groups can be either protonated or deprotonated depending on the pH of the background electrolyte; therefore, either an overall positively or negatively charged coating can be achieved. This zwitterionic coating allows protein separations in either normal or reverse polarity mode depending on the pH of the background electrolyte.

Achiral and chiral separations using MEKC, polyelectrolyte multilayer coatings, and mixed mode separation techniques with molecular micelles.

Mixed mode (MM) separation using a combination of MEKC and polyelectrolyte multilayer (PEM) coatings is herein reported for the separation of achiral and chiral analytes. Many analytes are difficult to separate by MEKC and PEM coatings alone. Therefore, the implementation of a MM separation provides several advantages for overcoming the limitations of these well-established methods.

Protein separations using polyelectrolyte multilayer coatings with molecular micelles in open tubular capillary electrochromatography.

Novel polyelectrolyte multilayer (PEM) coatings for enhanced protein separations in open tubular CEC (OT-CEC) are reported. Use of four cationic polymers (poly-L-lysine, poly-L-ornithine, poly-L-lysine-serine, and poly-L-glutamic acid-lysine), and three anionic molecular micelles, sodium poly(N-undecanoyl-L-leucyl-alaninate) (poly-L-SULA), sodium poly(N-undecanoyl-L-leucyl-valinate) (poly-L-SULV), and sodium poly(undecylenic sulfate) (poly-SUS) were investigated in PEM coatings for protein separations. The simultaneous effects of cationic polymer concentration, number of bilayers, temperature, applied voltage, and pH of the BGE on the separation of four basic proteins (alpha-chymotrypsinogen A, lysozyme, ribonuclease A, and cytochrome c) were analyzed using a Box Behnken experimental design.