title: Novel bis(5-methyltetrazolium)amine ligand-bonded stationary phase with reduced leakage of metal ions in immobilized metal affinity chromatography of proteins.
abstract: Immobilized metal affinity chromatography (IMAC) has been widely used for the specific separation of biopolymers. However, leakage of metal ions from IMAC adsorbents is of concern in IMAC. In this study, we designed a novel tridenate bis(5-methyltetrazolium)amine (BMTA) to reduce the leakage of metal ions by improving the affinity to immobilized metal ions. The ligand was bonded onto silica via three-step reaction to prepare a high-performance IMAC stationary phase. The chromatographic behaviors of ribonuclease A, cytochrome c, and lysozyme on the Cu(II)-, Ni(II)-, and Zn(II)-chelated stationary phase were investigated with respect to pH effect and elution with an imidazole gradient. The retention times of these three proteins increased by increasing the pH of the mobile phase but decreased by increasing the concentration of the competitive displacer. The retaining strength of the three proteins on the chelated stationary phase were in the order Cu(II) > Ni(II) > Zn(II). The behavior of these three proteins was consistent with the properties of a typical IMAC. The BMTA ligand exhibited a much stronger affinity for Cu(II) and Ni(II) than iminodiacetic acid (IDA), which is often regarded as a standard tridentate IMAC ligand. Quantum mechanical calculations at the B3LYP/6-31G level were used to image the coordination mode of the protein-metal ions-BMTA complex. In addition, a fused histidine-tagged cecropin b-human epidermal growth factor (CB-EGF) from Escherichia coli crude extract was purified by the Ni(II)-chelated stationary phase, and the purity of the CB-EGF was determined to be at least 90 %. These results suggest that the BMTA ligand may have potential applications in the preparation of therapeutics. Graphical Abstract A novel ligand of tridenate bis(5-methyltetrazolium)amine (BMTA) was designed to reduce the leakage of metal ions from the column in immobolized metal affinity chromatography (IMAC).
authors: Key Laboratory of Synthetic and Natural Function Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi, 710069, China.
authors: Chunmiao
authors: C
authors: Bo
authors: Key Laboratory of Synthetic and Natural Function Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi, 710069, China.
authors: Chaozhan
authors: C
authors: Wang
authors: Key Laboratory of Synthetic and Natural Function Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi, 710069, China. ymwei@nwu.edu.cn.
authors: Yinmao
authors: Y
authors: Wei
mesh_terms: D000327:Adsorption; D002846:Chromatography, Affinity / Q000379:methods*; D003300:Copper / Q000737:chemistry; D045304:Cytochromes c / Q000302:isolation & purification*; D004815:Epidermal Growth Factor / Q000302:isolation & purification; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry; D007098:Imino Acids / Q000737:chemistry; D009113:Muramidase / Q000302:isolation & purification*; D009532:Nickel / Q000737:chemistry; D011789:Quantum Theory; D012259:Ribonuclease, Pancreatic / Q000302:isolation & purification*; D012822:Silicon Dioxide / Q000737:chemistry; D013778:Tetrazolium Salts / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry
chemical_list: D007093:Imidazoles; D007098:Imino Acids; D013778:Tetrazolium Salts; D004815:Epidermal Growth Factor; D012822:Silicon Dioxide; D003300:Copper; C029899:imidazole; D009532:Nickel; D045304:Cytochromes c; D012259:Ribonuclease, Pancreatic; D009113:Muramidase; D015032:Zinc; C008109:iminodiacetic acid
keywords: Affinity adsorbents; Bis(5-methyltetrazolium)amine; Immobilized metal affinity chromatography; Proteins