Noncovalent poly(1‐vinylpyrrolidone)‐based copolymer coating for the separation of basic proteins and lipoproteins by CE

Abstract

A new simple and fast noncovalent coating method based on poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate) copolymer was developed for CE. Merely 2 min flushing of the capillary with the poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate) copolymer was required. The copolymer is adsorbed onto the fused-silica surface by hydrogen bonding and electrostatic interactions. EOF was almost totally suppressed over a wide pH range. The coating conditions (flushing time, copolymer concentration, and the concentration and pH of background electrolyte solution) and the stability of the coating were optimized, and the coated capillary was successfully applied to the fast separation of four basic proteins: lysozyme, cytochrome c, ribonuclease A, and alpha-chymotrypsinogen A. Separation efficiencies were high, ranging from 386 000 to 738 000 plates/m at 40 mM pH 4.0 acetate buffer being comparable to values obtained on classical covalent PVP-coated capillary. The RSD of migration times of basic proteins for 200 times successive runs were all below 1.0% (n=200, 3 days). A successful capillary performance was demonstrated also to the separation of low- and high-density lipoproteins at acidic pH.

Cationic poly(amidoamine) dendrimers as additives for capillary electroseparation and detection of proteins

“…Therefore, the influence of PAMAMs as additives on separation performance varies with buffer pH. On the other hand, buffers of wide pH range have been employed for high performance separation of proteins by CE/CEC, from extremely acidic [15], mild acidic [16][17][18][19][20] to neutral [12,[21][22][23][24], mild alkaline [25,26] and extremely alkaline [27]. Therefore, examining the properties of PAMAM dendrimers as additives in different pHs is helpful in extending their potential applications in protein analysis.…”

A novel cationic triblock copolymer as noncovalent coating for the separation of proteins by CE

“…QDED was different from P (VP-co-DMAEMA) [28] and HEC-g-PDMAEMA [33], because the weak positively charged amine groups in PDMAEMA block were quaternized to take with positive charges not only in acid solution, but also in alkaline solution, therefore the chain backbone of quaternized PDMAEMA block strongly adsorbed onto the capillary surface through electrostatic interactions. However, P(VPco-DMAEMA) and HEC-g-PDMAEMA were pH-sensitive polymers, the net positive charges were decreasing with the increasing of pH value.…”

“…Neutral polymers are easily rinsed away from the capillary wall, the polymer of PDMA adsorbed to the capillary wall tightly but it would interact with proteins via hydrophobic interactions. To combine advantages of different homopolymers, several kinds of copolymers were synthesized recently, such as poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate) (P(VP-co-DMAEMA)) [28], poly (ethylpyrrolidine methacrylate-methylmethacrylate) (EPyM-MMA) [29], poly(N,N-dimethylacrylamide-co-4-(ethyl)-morpholine methacrylamide) (DMA-MAEM) [30], poly (ethylene oxide)-block-poly(4-vinylpyridine) (PEO-b-P4VP) [31], and some derivatized HEC coatings were developed in our laboratory [32][33][34].…”

Poly(ethylene glycol)‐coated microfluidic devices for chip electrophoresis

“…This method is easily adaptable for microfluidic systems. For this purpose, several surface-active materials, mainly polymer-based such as poly(vinyl alcohol) (PVA) [5], poly(ethylene glycol) (PEG) [6], hydroxyethylcellulose [7], cationized-hydroxyethylcellulose [8], poly(vinyl pyrrolidone) [9] or different copolymers [10][11][12][13] were described in the CE and MCE literature. Other suitable surface-active compounds are surfactants [14,15], polyelectrolyte multilayers [16,17] or ionic liquids [18].…”