Synthesis of magnetic Fe3O4@PS-ANTA-M2+ (M = Ni, Co, Cu and Zn) nanospheres for specific isolation of histidine-tagged proteins

Highly Selective Entrapment of His-Tagged Enzymes on Superparamagnetic Zirconium-Based MOFs with Robust Renewability to Enhance pH and Thermal Stability

“…Thus, the immobilized enzymes showed a wide range of pH stability. The formation of coordination bonds between the unsaturated zirconium ion in the carrier and the lone electron pair of N on the histidine of the imidazole ring of His-tagged protein 48 could enhance the rigidity of the enzymes and prevent the destruction of the tertiary structure of AbGUS under alkaline environments. Thus, the excellent alkali stability of Fe 3 O 4 @ UiO66@AbGUS noticeably widened the alkali endurance ranges of enzymes, resulting in extending its practical applications, especially at high pH conditions.…”

SiO2-Coated Fe3O4 Nanoparticle/Polyacrylonitrile Beads for One-Step Lipase Immobilization

“…Magnetic Fe 3 O 4 nanoparticles were synthesized through the chemical co-precipitation of Fe 2+ and Fe 3+ chloride salts . Typically, in a single-neck flask, a mixture of 12 g FeCl 3 ·6H 2 O and 4.6 g FeCl 2 ·4H 2 O (the molar ratio was 2:1) was prepared and stirred vigorously in 50 mL of H 2 O at room temperature (RT), and then, the pH of the solution was adjusted to 10–12 via aqueous ammonia (25%) to get a black suspension.…”

“…Additionally, commercial Novo 435 was chosen to evaluate the prospects of L/FP in industrial applications, such as ester hydrolysis. 59 Typically, in a single-neck flask, a mixture of 12 g FeCl 3 •6H 2 O and 4.6 g FeCl 2 •4H 2 O (the molar ratio was 2:1) was prepared and stirred vigorously in 50 mL of H 2 O at room temperature (RT), and then, the pH of the solution was adjusted to 10−12 via aqueous ammonia (25%) to get a black suspension. Then, the suspension was heated at 70 °C for 40 min with the protection of 2 mL of hydrazine hydrate.…”

One-Step Synthesis of Sustainable Montmorillonite-Supported, Copper-Doped Magnetic Nanoparticles for Highly Specific Separation of His-Rich Proteins

“…Among the transition-metal ions (Cu 2+ , Ni 2+ , Zn 2+ , Co 2+ ), 12−15 copper ions displayed the strongest affinity for His-rich proteins due to the fact that Cu 2+ not only specifically binds to the histidine sites but also strongly interacts with the peptide C-terminus. 16,17 However, the magnetic cores of copper ionimmobilized adsorbents usually need to be modified by some ligands to further anchor Cu 2+ , including iminodiacetic acid (IDA), 18,19 diethylene triamine pentacetate acid (DTPA), 20 or ethylenediaminetetraacetic acid (EDTA). 21 The problems of Cu 2+ leaching during the adsorption and desorption processes possibly cause environmental metal pollution and poor reusability of adsorbents that suffer from multiple incubation processes with a fresh copper salt solution to be resued.…”

“…Among the available methods, immobilized metal affinity chromatography (IMAC) is considered a potent methodology for selective separation of Hb because of the coordination bonds formed between the histidine residuals of proteins and immobilized transition-metal ions. − However, the limitation of low adsorption capacity, long contact and separation time, and cumbersome operation for IMAC greatly restrict its application, especially for complex biological specimens. , To address such shortcomings, the adsorbents based on magnetic nanomaterials with immobilized transition-metal ions as specific adsorbents for His-rich proteins are proposed. Among the transition-metal ions (Cu 2+ , Ni 2+ , Zn 2+ , Co 2+ ), − copper ions displayed the strongest affinity for His-rich proteins due to the fact that Cu 2+ not only specifically binds to the histidine sites but also strongly interacts with the peptide C-terminus. , However, the magnetic cores of copper ion-immobilized adsorbents usually need to be modified by some ligands to further anchor Cu 2+ , including iminodiacetic acid (IDA), , diethylene triamine pentacetate acid (DTPA), or ethylenediaminetetraacetic acid (EDTA) . The problems of Cu 2+ leaching during the adsorption and desorption processes possibly cause environmental metal pollution and poor reusability of adsorbents that suffer from multiple incubation processes with a fresh copper salt solution to be resued. , Thus, simple and sustainable magnetic adsorbents for specific separation of His-rich proteins are desired for the application.…”