Core–shell molecular imprinting of nanomaterials overcomes difficulties with template transfer and achieves higher binding capacities for macromolecular imprinting, which are more important to the imprinting of natural low-abundance proteins from cell extracts. In the present study, a novel strategy of preparing core–shell nanostructured molecularly imprinted polymers (MIPs) was developed that combined the core–shell approach with assistant recognition polymer chains (ARPCs). Vinyl-modified silica nanoparticles were used as support and ARPCs were used as additional functional monomers. Immunoglobulin heavy chain binding protein (BiP) from the endoplasmic reticulum (ER) was chosen as the model protein. The cloned template protein BiP was selectively assembled with ARPCs from their library, which contained numerous limited-length polymer chains with randomly distributed recognition and immobilization sites. The resulting complex was copolymerized onto the surface of vinyl-modified silica nanoparticles under low concentrations of the monomers. After template removal, core–shell-structured nanoparticles with a thin imprinted polymer layer were produced. The particles demonstrated considerably high adsorption capacity, fast adsorption kinetics and selective binding affinities toward the template BiP. Furthermore, the synthesized MIP nanoparticles successfully isolated cloned protein BiP from protein mixtures and highly enriched BiP from an ER extract containing thousands of kinds of proteins. The enrichment reached 115-fold and the binding capacity was 5.4 μg g−1, which were higher than those achieved by using traditional MIP microspheres. The advantageous properties of MIP nanoparticles hold promise for further practical applications in biology, such as protein analysis and purification.
In this study, a novel method of selective protecting group based on molecularly imprinted polymer for regioselective organic reaction is reported. The simplicity, convenience and feasibility of this method may be illustrated by the protection of hydroxyl group at C17 or C3 of β-estradiol in the reaction between β-estradiol and diphenylphosphinic chloride. Polymers to protect hydroxyl group at C17 or at C3, both demonstrated excellent protection effect. In polymers imprinted with 2-methyl-cyclopentanol template to protect hydroxyl group at C17, the proportion of 3-phosphate was almost as high as 100%. In molecularly imprinted polymer synthesized using 5,6,7,8-Tetrahydro-2-naphthol as a template to protect hydroxyl group at C3, the proportion of 17-phosphate reached 98.2%. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
We introduce a new type of molecular imprinted polymer (MIP) with immobilized assistant recognition polymer chains (ARPCs) to create effective recognition sites. In this work, cloned pig cyclophilin 18 (pCyP18) and BSA were used as templates, respectively. The template protein was selectively assembled with ARPCs from the library which consists of numerous limited length polymer chains with randomly distributed recognition sites of the quaternary ammonium cationic groups and immobilizing sites. The assemblies of protein and ARPCs were adsorbed by macroporous microspheres and immobilized by cross-linking polymerization. After removing the templates, the two kinds of synthesized MIPs were used to adsorb cloned pCyP18 and BSA from protein mixtures respectively and both showed high selectivity. It confirms that this new method is suitable to separate proteins of both low and high molecular weight. The extended experiment on adsorption of natural pCyP18 from cytosol shows that the obtained MIP using cloned protein as template can be used to enrich natural protein of low content.
![1H-Cyclohepta[ghi]perylene-5,12-dione,3-acetyl-6,11-dihydroxy-4,8,9,13-tetramethoxy-2-methyl-](/data/chemimg/102900/123940-54-5.png)
![1H-Cyclohepta[ghi]perylene-5,12-dione,3-acetyl-6,11-dihydroxy-4,8,9,13-tetramethoxy-2-methyl-](/data/chemimg/102900/123940-54-5_b.png)
