Phospholipid Bilayer Coatings for the Separation of Proteins in Capillary Electrophoresis

Abstract

The double-chained, zwitterionic phospholipid 1,2-dilauroyl-sn-phosphatidylcholine (DLPC, C12) was investigated for its use as a wall coating for the prevention of protein adsorption in capillary electrophoresis. DLPC forms a semipermanent coating at the capillary wall, which allows excess phospholipid to be removed from the capillary prior to electrophoretic separation. A DLPC-coated capillary allowed for the separation of both cationic and anionic proteins with efficiencies as high as 1.4 million plates/m. Migration time reproducibility was less than 1.3% RSD from run to run and less than 4.0% RSD from day to day. Protein recovery was as high as 93%. Cationic and anionic proteins could be separated over a pH range of 3-10, all yielding good efficiencies (N up to 1 million plates/m). The chain length of the phospholipid affected the performance of the wall coating. The C10 analogue of DLPC (DDPC) did not form a coating on the capillary wall while the C14 analogue of DLPC (DMPC) formed a stable coating that prevented protein adsorption to the same extent as its C12 counterpart.

Poly(ethylene oxide) facilitates the characterization of an affinity between strongly basic proteins with DNA by affinity capillary electrophoresis

“…As shown in Tab. 2, efficiency obtained for kin17 peak in our conditions is not as high as that reported previously for cationic proteins using permanent or dynamic coating [33,34]. This can be attributed mainly to the low ionic strength of the running buffer we employed, in order to avoid a dissociating effect of the BGE on the kin17-ssDNA complex formed.…”

Surface treatment and characterization: Perspectives to electrophoresis and lab‐on‐chips

“…The electoosmotic mobility is derived from the time difference between the different plugs. Among others, Chiari et al [29], Cretich et al [30], and Cunliffe et al [31] have used this method to measure the EOF in CE in order to characterize their capillary surface modification.…”

“…The oxirane rings of the glycidyl ether monomers present a strong interaction (which has not been shown to be covalent) with silanol groups of the capillary, leading to a stable coating over hundreds of hours. This polymer was shown to be suitable for protein separations and for DNA separation [31].…”

Recent advances in the study of biomolecular interactions by capillary electrophoresis

“…The adsorption results in peak fronting or tailing, detrimental to quantitation, especially in ACE. Coating the capillary wall is a well established approach to repress adsorption [149,150].…”