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721.
Longyi Zhu Bernardino J. Córdova Wong Yang Li Hao Xin Prof. Dr. Bin Liu Prof. Dr. Jianping Lei 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(18):4665-4669
Distinguishing glutathione (GSH) level in different subcellular locations is critical for studying its antioxidant function in the signaling system. However, traditional methods for imaging subcellular GSH were achieved in isolated organelles or fixed cells. In this work, we report a quencher-delocalized emission strategy for in situ profiling of GSH at different subcellular locations in living cells. A nonemissive metal–organic framework (MOF) nanoprobe was designed with AIEgen as the linker and CuII as the node and quencher. The AIEgen in MOF structure was lightened up with green emission in a neutral environment due to partial CuII delocalization by competitive binding to GSH. Meanwhile, along with the protonation of AIEgen ligand under acidic environment, the AIEgen-based MOF could be completely dissociated in the presence of GSH to yield yellow emission. The two-channel ratiometric analysis of dual-colored emission of AIEgen-based MOF allows visualization of GSH in cytoplasm and lysosome in living cells, which is also able to report the drug effects on different subcellular GSH levels. 相似文献
722.
Dr. Kazuya Matsuo Yuki Nishikawa Marie Masuda Prof. Itaru Hamachi 《Angewandte Chemie (International ed. in English)》2018,57(3):659-662
The development of bioorthogonal approaches for labeling of endogenous proteins under the multimolecular crowding conditions of live cells is highly desirable for the analysis and engineering of proteins without using genetic manipulation. N‐Sulfonyl pyridone (SP) is reported as a new reactive group for protein sulfonylation. The ligand‐directed SP chemistry was able to modify not only purified proteins in vitro, but also endogenous ones on the surface of and inside live cells selectively and rapidly, which allowed to convert endogenous proteins to FRET‐based biosensors in situ. 相似文献
723.
Avoiding Thiol Compound Interference: A Nanoplatform Based on High‐Fidelity Au–Se Bonds for Biological Applications 下载免费PDF全文
Bo Hu Dr. Fanpeng Kong Dr. Xiaonan Gao Lulu Jiang Xiaofeng Li Dr. Wen Gao Prof. Kehua Xu Prof. Bo Tang 《Angewandte Chemie (International ed. in English)》2018,57(19):5306-5309
Gold nanoparticles (Au NPs) assembled through Au?S covalent bonds have been widely used in biomolecule‐sensing technologies. However, during the process, detection distortions caused by high levels of thiol compounds can still significantly influence the result and this problem has not really been solved. Based on the higher stability of Au?Se bonds compared to Au?S bonds, we prepared selenol‐modified Au NPs as an Au‐Se nanoplatform (NPF). Compared with the Au‐S NPF, the Au‐Se NPF exhibits excellent anti‐interference properties in the presence of millimolar levels of glutathione (GSH). Such an Au‐Se NPF that can effectively avoid detection distortions caused by high levels of thiols thus offers a new perspective in future nanomaterial design, as well as a novel platform with higher stability and selectivity for the in vivo application of chemical sensing and clinical therapies. 相似文献
724.
Ligand‐Induced Conformational Changes in HSP90 Monitored Time Resolved and Label Free—Towards a Conformational Activity Screening for Drug Discovery 下载免费PDF全文
Dr. Jörn Güldenhaupt Dr. Marta Amaral Dr. Carsten Kötting Dr. Jonas Schartner Dr. Djordje Musil Dr. Matthias Frech Prof. Dr. Klaus Gerwert 《Angewandte Chemie (International ed. in English)》2018,57(31):9955-9960
Investigation of protein–ligand interactions is crucial during early drug‐discovery processes. ATR‐FTIR spectroscopy can detect label‐free protein–ligand interactions with high spatiotemporal resolution. Here we immobilized, as an example, the heat shock protein HSP90 on an ATR crystal. This protein is an important molecular target for drugs against several diseases including cancer. With our novel approach we investigated a ligand‐induced secondary structural change. Two specific binding modes of 19 drug‐like compounds were analyzed. Different binding modes can lead to different efficacy and specificity of different drugs. In addition, the kobs values of ligand dissociation were obtained. The results were validated by X‐ray crystallography for the structural change and by SPR experiments for the dissociation kinetics, but our method yields all data in a single and simple experiment. 相似文献
725.
Xin Mao Dr. Peiyan Yuan Prof. Dr. Changmin Yu Prof. Dr. Lin Li Prof. Dr. Shao Q. Yao 《Angewandte Chemie (International ed. in English)》2018,57(32):10257-10262
Changes in the cellular levels of glutathione (GSH) and protein S‐glutathionylation (PSSG) are closely associated with a number of human diseases. Despite recent advances, few thiol‐reactive, small‐molecule GSH sensors could selectively detect GSH over other endogenous thiols, and none was capable of detecting PSSG in live mammalian cells. By using a dye‐loaded mesoporous silica nanoquencher (qMSN) capped with anti‐GSH antibody capable of highly selective binding toward GSH and glutathionylated proteins over other molecules, we have successfully developed a fluorescence GSH/PSSG nanosensor, which showed unprecedented selectivity toward PSSG even in the presence of GSH, had amplifiable and programmable fluorescence Turn‐ON properties, and could be used to image endogenous PSSG in live mammalian cells under stimulated conditions for the first time. 相似文献
726.
《Electroanalysis》2018,30(9):2044-2052
Acid functionalized multi‐walled carbon nanotubes (f‐MWCNTs) were decorated with Au and Fe2O3 nanoparticles (FeONPs) and deposited on glassy carbon electrode (GCE). The resulting hybrid Au/Fe2O3/f‐MWCNTs/GCE electrode and the one further modified by glucose oxidase were compared for detection of glucose. FeONPs and Au were deposited on the f‐MWCNTs by sonication‐assisted precipitation and deposition‐precipitation methods, respectively. The morphology and structure of the samples were characterized by transmission electron microscopy, scanning electron microscopy, X‐ray diffraction and Raman spectroscopy. A uniform distribution of FeONPs with an average size of 5 nm increased the surface area of functionalized nanotubes from 39 to 50 m2/g. The electrocatalytic glucose detection on the modified electrodes was evaluated using cyclic voltammetry and chronoamperometry in 0.1 M phosphate buffer solution at pH 7.0. The non‐enzymatic and enzymatic electrodes show sensitivity of 512.4 and 921.4 mA/mM.cm2 and detection limit of 1.7 and 0.9 mM, respectively. The enzymatic and enzymeless electrodes retained more than 70 % and 80 % of their cathodic faradic current after 70 days, respectively. The sensing mechanism of the non‐enzymatic biosensor is described through the reaction of glucose with iron (III) ions, while in the case of enzymatic electrode, glucose is oxidized by glucose oxidase. 相似文献
727.
S. D. Varfolomeyev E. A. Zaitseva T. A. Osipova 《Applied biochemistry and biotechnology》1996,61(1-2):173-188
The article describes the research activities in the field of enzyme engineering in Russia. The discussion is focused on fundamental
studies of biocatalytic processes that expand utilization of enzymes, biocatalytic synthesis of organic products from renewable
raw mate rials, enzymes for hydrolysis of cellulose and lignocellulose materials, immobilized cells, new enzyme-based drugs,
enzymes in fine organic synthesis, bioanalytic devices, biosensors, and biofuels. 相似文献
728.
Zhongchao Jin Xiaorong Zhu Ningning Wang Yafei Li Huangxian Ju Jianping Lei 《Angewandte Chemie (International ed. in English)》2020,59(26):10446-10450
Metal–organic frameworks (MOFs) have limited applications in electrochemistry owing to their poor conductivity. Now, an electroactive MOF (E‐MOF) is designed as a highly crystallized electrochemiluminescence (ECL) emitter in aqueous medium. The E‐MOF contains mixed ligands of hydroquinone and phenanthroline as oxidative and reductive couples, respectively. E‐MOFs demonstrate excellent performance with surface state model in both co‐reactant and annihilation ECL in aqueous medium. Compared with the individual components, E‐MOFs significantly improve the ECL emission due to the framework structure. The self‐enhanced ECL emission with high stability is realized by the accumulation of MOF cation radicals via pre‐reduction electrolysis. The self‐enhanced mechanism is theoretically identified by DFT. The mixed‐ligand E‐MOFs provide a proof of concept using molecular crystalline materials as new ECL emitters for fundamental mechanism studies. 相似文献
729.
Marianna Rossetti Simone Brannetti Marco Mocenigo Bruna Marini Rudy Ippodrino Alessandro Porchetta 《Angewandte Chemie (International ed. in English)》2020,59(35):14973-14978
Easy‐to‐use platforms for rapid antibody detection are likely to improve molecular diagnostics and immunotherapy monitoring. However, current technologies require multi‐step, time‐consuming procedures that limit their applicability in these fields. Herein, we demonstrate effective molarity‐driven electrochemical DNA‐based detection of target antibodies. We show a highly selective, signal‐on DNA‐based sensor that takes advantage of antibody‐binding‐induced increase of local concentration to detect clinically relevant antibodies in blood serum. The sensing platform is modular, rapid, and versatile and allows the detection of both IgG and IgE antibodies. We also demonstrate the possible use of this strategy for the monitoring of therapeutic monoclonal antibodies in body fluids. Our approach highlights the potential of harnessing effective molarity for the design of electrochemical sensing strategies. 相似文献
730.
Jianguo Bai Hui Wei Bingling Li Lihua Song Lanyun Fang Zhaozi Lv Weihong Zhou Prof. Dr. Erkang Wang Prof. Dr. 《化学:亚洲杂志》2008,3(11):1935-1941
A novel [Ru(bpy)2(dcbpy)NHS] labeling/aptamer‐based biosensor combined with gold nanoparticle amplification for the determination of lysozyme with an electrochemiluminescence (ECL) method is presented. In this work, an aptamer, an ECL probe, gold nanoparticle amplification, and competition assay are the main protocols employed in ECL detection. With all the protocols used, an original biosensor coupled with an aptamer and [Ru(bpy)2(dcbpy)NHS] has been prepared. Its high selectivity and sensitivity are the main advantages over other traditional [Ru(bpy)3]2+ biosensors. The electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM) characterization illustrate that this biosensor is fabricated successfully. Finally, the biosensor was applied to a displacement assay in different concentrations of lysozyme solution, and an ultrasensitive ECL signal was obtained. The ECL intensity decreased proportionally to the lysozyme concentration over the range 1.0×10?13–1.0×10?8 mol L?1 with a detection limit of 1.0×10?13 mol L?1. This strategy for the aptasensor opens a rapid, selective, and sensitive route for the detection of lysozyme and potentially other proteins. 相似文献