A major challenge in performing reactions in biological systems is the requirement for low substrate concentrations, often in the micromolar range. We report that copper cross-linked single-chain nanoparticles (SCNPs) are able to significantly increase the efficiency of copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reactions at low substrate concentration in aqueous buffer by promoting substrate binding. Using a fluorogenic click reaction and dye uptake experiments, a structure-activity study is performed with SCNPs of different size and copper content and substrates of varying charge and hydrophobicity. The high catalytic efficiency and selectivity are attributed to a mechanism that involves an enzyme-like substrate binding process. Saturation-transfer difference (STD) NMR spectroscopy, 2D-NOESY NMR, kinetic analyses with varying substrate concentrations, and computational simulations are consistent with a Michaelis-Menten, two-substrate, random-sequential enzyme-like kinetic profile. This general approach may prove useful for developing more-sustainable catalysts and agents for biomedicine and chemical biology.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jacs.8b06875 | DOI Listing |
ACS Nano
December 2024
Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, China.
As the keystones of molecular electronics, high-quality nanodielectric layers are challenging to assemble due to the strictest criteria for their reliability and uniformity over a large area. Here, we report a strained poly(4-vinylphenol) monolayer, ready to be stacked to form defect-free wafer-scale nanodielectrics. The thickness of the nanodielectrics can be precisely adjusted in integral multiples of the 1.
View Article and Find Full Text PDFMikrochim Acta
December 2024
School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, 400054, China.
A novel proposal is introduced with an unlabeled electrochemical immunosensor for the detection of tumor broad-spectrum biomarker vascular endothelial growth factor (VEGF165) Copper-based metal organic frameworks (Cu MOFs)-carbon nanotubes (MWCNTs) were employed as its substrates, functionalized with methylene blue (MB) for signal enhancement. Cu-MOFs-MWCNTs nanocomposites were synthesized successfully via a solvothermal method and were then deposited on the surface of a glassy carbon electrode (GCE), with the addition of methylene blue to amplify the signal. Due to the expansive specific surface area provided by the carbon nanotubes and the amino groups facilitated by the metal-organic framework nanomaterials, the anti-VEGF165 monoclonal antibody was immobilized on the electrochemical immunosensor through covalent bonding, which could bind specifically to VEGF165, thereby causing a detectable change in the current.
View Article and Find Full Text PDFSci Rep
December 2024
Institute of Physics, University of São Paulo, São Carlos, 13560-590, SP, Brazil.
When combined with certain metal species, films of amorphous Ge or Si can have their typical crystallization temperatures decreased, by a factor of three or four, down to ~ 200 °C. The phenomenon is called metal-induced crystallization (MIC) and, since its first observation in the late 1960's, shows a great technological potential in producing (poly-)crystalline films of Ge or Si onto low-melting point substrates under reduced energy conditions. From the scientific point of view, the microscopic mechanisms behind the MIC phenomenon (still) represents a scientific challenge, where most of the proposed models are invariably influenced by the samples details giving the impression that they only apply to very specific metal-semiconductor combinations and/or circumstances.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Compared with chiral β-amino phosphorus compounds, which can be easily derived from natural optically pure α-amino acids, obtaining chiral β-amino phosphorus derivatives remains a challenge. These derivatives, which cannot be derived from chiral natural amino acids, possess unique biological activities or potential catalytic activities. Herein, highly enantioselective hydrogenation for the preparation of chiral β-amino phosphorus derivatives from -β-enamido phosphorus compounds is reported by using a green and low-cost earth-abundant metal nickel catalyst (13 examples of 99% ee).
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China.
Carrageenans have attracted increasing research interests in recent decades for their various physicochemical and physiological properties. Random endo-acting carrageenases are promising tools for tailoring the molecular weight of carrageenan and preparing a series of carrageenan oligosaccharides. Although the processive ι-carrageenases in the GH82 family have been widely investigated, the random ι-carrageenase has not been reported.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!