title: Simultaneous separation of acidic and basic proteins using gemini pyrrolidinium surfactants and hexafluoroisopropanol as dynamic coating additives in capillary electrophoresis.
abstract: The separation of acidic and basic proteins using CE has been limited in part due to the adsorption of proteins onto the capillary wall. In this work, the efficient control of EOF and the simultaneous separation of acidic and basic proteins are achieved by use of C18-4-C18PB as a dynamic coating additive, which is a representative surfactant for 1,1'-(butane-1,s-alkyl)bis(1-alkylpyrrolidinium) bromide (Cn-4-CnPB, n=10, 12, 14, 16 and 18). C18-4-C18PB exhibits a powerful capability in the reversal of EOF, and a low concentration even less than 0.001 mM is sufficient to reverse EOF at the tested pH values (3.0-9.0). Baseline separation of eight proteins with sharp peaks and high efficiencies (54,000-297,000 plates/m) is obtained with 30 mM NaH2PO4 buffer (pH 5.0) containing 4 mM C18-4-C18PB. At the same buffer condition, the Cn-4-CnPB with shorter alkyl chain (n=10, 12, 14, 16) cannot achieve the same effective protein separation as C18-4-C18PB. However, the combined use of small amounts (≤0.5%, v/v) of hexafluoroisopropanol (HFIP) and Cn-4-CnPB (n=10, 12, 14, 16) as additives can completely separate all eight proteins with high efficiencies of 81,000-318,000 plates/m. The RSDs of migration time are less than 0.80% and 5.84% for run-to-run and day-to-day assays (n=5), respectively, and the protein recoveries are larger than 90.15%. To the best of our knowledge, this is the first report on the simultaneous separation of acidic and basic proteins using Cn-4-CnPB surfactants or Cn-4-CnPB surfactants combined with HFIP as dynamic coating additives.
authors: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China.
authors: Yu
authors: Y
authors: Tian
authors: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China.
authors: Yunfang
authors: Y
authors: Li
authors: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China.
authors: Jie
authors: J
authors: Mei
authors: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
authors: Bo
authors: B
authors: Cai
authors: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
authors: Jinfeng
authors: J
authors: Dong
authors: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
authors: Zhiguo
authors: Z
authors: Shi
authors: Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China. Electronic address: yuxiuxiao2011@whu.edu.cn.
authors: Yuxiu
authors: Y
authors: Xiao
mesh_terms: D000327:Adsorption; D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods; D006863:Hydrogen-Ion Concentration; D020005:Propanols / Q000737:chemistry*; D011506:Proteins / Q000302:isolation & purification*; D011759:Pyrrolidines / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D006845:Hydrocarbons, Fluorinated
chemical_list: D002021:Buffers; D020005:Propanols; D011506:Proteins; D011759:Pyrrolidines; D013501:Surface-Active Agents; C001337:hexafluoroisopropanol; D006845:Hydrocarbons, Fluorinated
keywords: Capillary electrophoresis; Dynamic coating; Hexafluoroisopropanol; Protein separation; Pyrrolidinium gemini surfactant