Graft copolymer composed of cationic backbone and bottle brush-like side chains as a physically adsorbed coating for protein separation by capillary electrophoresis

✍ Scribed by Dan Zhou; Lina Xiang; Rongju Zeng; Fuhu Cao; Xiaoxi Zhu; Yanmei Wang

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 274 KB
• Volume: 34
• Category: Article
• ISSN: 1615-9306
• DOI: 10.1002/jssc.201100597

✦ Synopsis

Abstract

To stabilize electroosmotic flow (EOF) and suppress protein adsorption onto the silica capillary inner wall, a cationic hydroxyethylcellulose‐graft‐poly (poly(ethylene glycol) methyl ether methacrylate) (cat‐HEC‐g‐PPEGMA) graft copolymer composed of cationic backbone and bottle brush‐like side chains was synthesized for the first time and used as a novel physically adsorbed coating for protein separation by capillary electrophoresis. Reversed (anodal) and very stable EOF was obtained in cat‐HEC‐g‐PPEGMA‐coated capillary at pH 2.2–7.8. The effects of degree of cationization, PEGMA grafting ratio, PEGMA molecular mass, and buffer pH on the separation of basic proteins were investigated. A systematic comparative study of protein separation in bare and HEC‐coated capillaries and in cat‐HEC‐g‐PPEGMA‐coated capillary was also performed. The basic proteins can be well separated in cat‐HEC‐g‐PPEGMA‐coated capillary over the pH range of 2.8–6.8 with good repeatability and high separation efficiency, because the coating combines good protein‐resistant property of bottle brush‐like PPEGMA side chains with excellent coating ability of cat‐HEC backbone. Besides its success in separation of basic proteins, the cat‐HEC‐g‐PPEGMA coating was also superior in the fast separation of other protein samples, such as protein mixture, egg white, and saliva, which indicates that it is a promising coating for further proteomics analysis.