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Nanoparticle‐based capillary electroseparation of proteins in polymer capillaries under physiological conditions
Author(s) -
Nilsson Christian,
Harwigsson Ian,
Becker Kristian,
Kutter Jörg P.,
Birnbaum Staffan,
Nilsson Staffan
Publication year - 2010
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200900464
Subject(s) - nanoparticle , capillary electrochromatography , capillary action , chromatography , adsorption , chemistry , fluorescence , polymer , aqueous solution , protein adsorption , capillary electrophoresis , chemical engineering , materials science , nanotechnology , organic chemistry , physics , quantum mechanics , engineering , composite material
Totally porous lipid‐based liquid crystalline nanoparticles were used as pseudostationary phase for capillary electroseparation with LIF detection of proteins at physiological conditions using unmodified cyclic olefin copolymer capillaries (Topas ® , 6.7 cm effective length). In the absence of nanoparticles, i.e. in CE mode, the protein samples adsorbed completely to the capillary walls and could not be recovered. In contrast, nanoparticle‐based capillary electroseparation resolved green fluorescent protein from several of its impurities within 1 min. Furthermore, a mixture of native green fluorescent protein and two of its single‐amino‐acid‐substituted variants was separated within 2.5 min with efficiencies of 400 000 plates/m. The nanoparticles prevent adsorption by introducing a large interacting surface and by obstructing the attachment of the protein to the capillary wall. A one‐step procedure based on self‐assembly of lipids was used to prepare the nanoparticles, which benefit from their biocompatibility and suspension stability at high concentrations. An aqueous tricine buffer at pH 7.5 containing lipid‐based nanoparticles (2% w/w) was used as electrolyte, enabling separation at protein friendly conditions. The developed capillary‐based method facilitates future electrochromatography of proteins on polymer‐based microchips under physiological conditions and enables the initial optimization of separation conditions in parallel to the chip development.