Concanavalin A (Con A) was selected as ligand and thus immobilized onto two different supports, namely the polymeric Toyopearl and the inorganic silica, with the protection of its binding sites provided during the coupling procedure. The prepared Con A affinity adsorbents were then employed to evaluate their adsorption behaviour for the enzyme glucose oxidase (GOD). The immobilization kinetics showed that the immobilization of Con A on silica supports was much faster than that on Toyopearl supports, which could highly reduce the possibility of the denaturation of Con A. The optimal adsorption conditions for binding of GOD onto the ligand were determined in terms of the pH value and the ionic strength of the adsorption medium. The adsorption isotherms for binding GOD onto two Con A affinity adsorbents fitted well with the Langmuir equation. The maximum adsorption capacity q(m) of Toyopearl Con A and silica Con A were 7.9 mg/ml and 4.9 mg/ml, with a dissociation constant K(d) of 4.8 x 10(-7)M and 2.6 x 10(-6)M, respectively. Due to the less diffusive resistance, silica Con A showed both higher adsorption and desorption rates for GOD when compared with Toyopearl Con A. The nonspecific adsorption of GOD was less than 8% for both end-capped Toyopearl and silica supports. The dynamic adsorption of GOD for five times repeated processes showed a high stability for both prepared adsorbents. All the results indicate a good suitability of both Con A adsorbents for affinity adsorption of GOD.
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http://dx.doi.org/10.1016/j.jchromb.2007.07.020 | DOI Listing |
Nat Commun
January 2025
Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
Dual active sites with synergistic valence state regulation under oxidizing and reducing conditions are essential for catalytic reactions with step-wise mechanisms to modulate the complex adsorption sites of reactant molecules on the surfaces of heterogeneous catalysts with maximized catalytic performances, but it has been rarely explored. In this work, uniformly dispersed CuCo alloy and CoO nanosheet composite catalysts with dual active sites are constructed, which shows huge boost in activity for catalyzing water-gas shift reaction (WGSR), with a record high reaction rate reaching 204.2 μmol g s at 300 °C for CuCoO amongst the reported Cu-based and Co-based catalysts.
View Article and Find Full Text PDFSci Total Environ
January 2025
Inner Mongolia Key Laboratory of Advanced Ceramic Material and Devices, Baotou 014010, China.
Selective recovery of rare earth elements (REEs) from environmental waste is strategically significant. Herein, Ce(III) imprinted EDTA modified chitosan-magnetic graphene oxide (IIP-EDTA-CS-MGO) was prepared for selective recovery of Ce(III). Furthermore, adsorption mechanism was clarified based on versatile adsorption fittings and spectroscopic tests.
View Article and Find Full Text PDFTalanta
January 2025
College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing, 211816, China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing, 211816, China. Electronic address:
Enzyme immobilization techniques are crucial for enhancing enzyme stability and catalytic efficiency. Traditional methods such as physical adsorption and simple covalent binding often fail to maintain enzyme activity and stability. In this study, an innovative multi-level immobilization strategy was proposed to achieve efficient targeted immobilization of nuclease P1 (NP1) by fine-tuning the surface microenvironment.
View Article and Find Full Text PDFMikrochim Acta
January 2025
School of Public Health, Hebei Key Laboratory of Occupational Health and Safety for Coal Industry, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian, Tangshan, 063210, Hebei, China.
Biochars (BCs) derived from waste-branches of apple tree, grape tree, and oak were developed for direct solid-phase extraction (SPE) of five benzodiazepines (BZDs) in crude urine samples prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination. Scanning electron microscopy, elemental analyzer, X-ray diffractometry, N adsorption/desorption experiments, and Fourier transform infrared spectrometry characterizations revealed the existence of their mesoporous structure and numerous oxygen-containing functional groups. The obtained BCs not only possessed high affinity towards BZDs via π-π and hydrogen bond interactions, but also afforded the great biocompatibility of excluding interfering components from undiluted urine samples when using SPE adsorbents.
View Article and Find Full Text PDFSmall
January 2025
Department of Chemistry, University of Miami, Coral Gables, FL, 33146, USA.
The controlled binding of proteins on nanoparticle surfaces remains a grand challenge required for many applications ranging from biomedical to energy storage. The difficulty in achieving this ability arises from the different functional groups of the biomolecule that can adsorb on the nanoparticle surface. While most proteins can only adopt a single structure, metamorphic proteins can access at least two different conformations, which presents intriguing opportunities to exploit such structural variations for binding to nanoparticles.
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