34,676 results match your criteria synthetic ion

Construction of cadmium whole-cell biosensors and circuit amplification.

Appl Microbiol Biotechnol 2021 Jun 23. Epub 2021 Jun 23.

Department of Chemical Engineering, University of New Hampshire, Durham, NH, 03824, USA.

Owing to the prevalence of cadmium contamination and its serious hazards, it is important to establish an efficient and low-cost monitoring technique for the detection of the heavy metal cadmium. In this study, we first designed 30 cadmium whole-cell biosensors (WCBs) using different combinations of detection elements, reporting elements, and the host. The best performing WCB KT-5-R with Pseudomonas putida KT2440 as the host and composed of CadR and mCherry was selected for further analysis and engineering. Read More

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Fabrication, functionalization and advanced applications of magnetic hollow materials in confined catalysis and environmental remediation.

Nanoscale 2021 Jun 22. Epub 2021 Jun 22.

Green Chemistry Network Centre, Department of Chemistry, University of Delhi, Delhi-110007, India.

Magnetic hollow-structured functional hybrid materials with unique architectures and preeminent properties have always been an area of extensive research. They represent a subtle collaboration of hollow architecture, mesoporous nanostructure and magnetic character. Owing to the merits of a large void space, low density, high specific surface area, well-defined active sites and facile magnetic recovery, these materials present promising application projections in numerous fields, such as drug delivery, adsorption, storage, catalysis and many others. Read More

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Insights into Catalytic Hydrolysis of Organophosphonates at M-OH Sites of Azolate-Based Metal Organic Frameworks.

J Am Chem Soc 2021 Jun 23. Epub 2021 Jun 23.

International Institute of Nanotechnology and Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.

Organophosphorus nerve agents, a class of extremely toxic chemical warfare agents (CWAs), have remained a threat to humanity because of their continued use against civilian populations. To date, Zr(IV)-based metal organic framework (MOFs) are the most prevalent nerve agent hydrolysis catalysts, and relatively few reports disclose MOFs containing nodes with other Lewis acidic transition metals. In this work, we leveraged this synthetic tunability to explore how the identity of the transition metal node in the M-MFU-4l series of MOFs (M = Zn, Cu, Ni, Co) influences the catalytic performance toward the hydrolysis of the nerve agent simulant dimethyl (4-nitrophenyl)phosphate (DMNP). Read More

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Simple and Sensitive Multi-components Detection Using Synthetic Nitrogen-doped Carbon Dots Based on Soluble Starch.

J Fluoresc 2021 Jun 22. Epub 2021 Jun 22.

The First College of Clinical Medical Science, China Three Gorges University, Yichang, 443003, China.

Although carbon dots (CDs) as fluorescent sensors have been widely exploited, multi-component detection using CDs without tedious surface modification is always a challenging task. Here, two kinds of nitrogen-doped CDs (NCD-m and NCD-o) based on soluble starch (SS) as carbon source were prepared through one-pot hydrothermal process using m-phenylenediamine and o-phenylenediamine as nitrogenous dopant respectively. Through fluorescence "on-off" mechanism of CDs, NCD-m and NCD-o could be used as a fluorescence sensor for detection of Fe and Ag with LOD of 0. Read More

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Two-Dimensional Planar BGe Monolayer as an Anode Material for Sodium-Ion Batteries.

ACS Appl Mater Interfaces 2021 Jun 21. Epub 2021 Jun 21.

School of Materials, Zhengzhou University of Aeronautics, Zhengzhou 450015, China.

Using first-principles swarm intelligence structure prediction computations, we explore a fully planar BGe monolayer with unique mechanical and electrical properties. Theoretical calculations reveal that a free-standing BGe monolayer has excellent stability, which is confirmed by the cohesive energy (compared to experimentally synthetic borophene and germanene monolayers), phonon modes (no imaginary frequencies appeared in the phonon spectrum), ab initio molecular dynamics (AIMD) simulations (no broken bonds and geometric reconstructions), and mechanical stability criteria. The metallic feature of the BGe monolayer can be maintained after absorbing different numbers of Na atoms, ensuring good electronic conductivity during the charge/discharge process. Read More

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A chiral lanthanide tag for stable and rigid attachment to single cysteine residues in proteins for NMR, EPR and time-resolved luminescence studies.

Chemistry 2021 Jun 21. Epub 2021 Jun 21.

Loughborough University, Chemistry, Epinal Way, LE11 3TU, Loughborough, UNITED KINGDOM.

A lanthanide-binding tag site-specifically attached to a protein presents a tool to probe the protein by multiple spectroscopic techniques, including nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) and time-resolved luminescence spectroscopy experiments. Here we present a new stable chiral Ln(III) tag, referred to as C12, for spontaneous and quantitative reaction with a cysteine residue generating a stable thioether bond. The synthetic protocol of the tag is relatively straightforward and the tag is stable for storage and shipping. Read More

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New avenues for mechanochemistry in zeolite science.

Dalton Trans 2021 Jun 21. Epub 2021 Jun 21.

School of Chemistry, EaStCHEM, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK. and Department of Physical and Macromolecular Chemistry, Faculty of Sciences, Charles University, Hlavova 8, 128 43 Prague 2, Czech Republic.

Zeolites are a class of microporous materials with tremendous value for large scale industrial applications such as catalysis, ion exchange, or gas separation. In addition to naturally ocurring variants, zeolites are made synthetically using hydrothermal synthesis, requiring temperatures beyond 100 °C and long reaction times up to weeks. Furthermore, specific applications may require more sophisticated synthesis conditions, expensive reagents, or post-synthetic modifications. Read More

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An Ultra-microporous Carbon Material Boosting Integrated Capacitance for Cellulose-Based Supercapacitors.

Nanomicro Lett 2020 Feb 24;12(1):63. Epub 2020 Feb 24.

State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.

A breakthrough in advancing power density and stability of carbon-based supercapacitors is trapped by inefficient pore structures of electrode materials. Herein, an ultra-microporous carbon with ultrahigh integrated capacitance fabricated via one-step carbonization/activation of dense bacterial cellulose (BC) precursor followed by nitrogen/sulfur dual doping is reported. The microporous carbon possesses highly concentrated micropores (~ 2 nm) and a considerable amount of sub-micropores (< 1 nm). Read More

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February 2020

TiN Paper for Ultrafast-Charging Supercapacitors.

Nanomicro Lett 2019 Dec 10;12(1). Epub 2019 Dec 10.

Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA, 95064, USA.

Ultrafast-charging energy storage devices are attractive for powering personal electronics and electric vehicles. Most ultrafast-charging devices are made of carbonaceous materials such as chemically converted graphene and carbon nanotubes. Yet, their relatively low electrical conductivity may restrict their performance at ultrahigh charging rate. Read More

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December 2019

VO Nanospheres with Mixed Vanadium Valences as High Electrochemically Active Aqueous Zinc-Ion Battery Cathode.

Nanomicro Lett 2019 Mar 22;11(1):25. Epub 2019 Mar 22.

School of Materials Science and Engineering, Central South University, Changsha, 410083, Hunan, People's Republic of China.

A V-VO cathode with mixed vanadium valences was prepared via a novel synthetic method using VOOH as the precursor, and its zinc-ion storage performance was evaluated. The products are hollow spheres consisting of nanoflakes. The V-VO cathode exhibits a prominent cycling performance, with a specific capacity of 140 mAh g after 1000 cycles at 10 A g, and an excellent rate capability. Read More

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Kinetic mechanism of Na-coupled aspartate transport catalyzed by Glt.

Commun Biol 2021 Jun 17;4(1):751. Epub 2021 Jun 17.

Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.

It is well-established that the secondary active transporters Glt and Glt catalyze coupled uptake of aspartate and three sodium ions, but insight in the kinetic mechanism of transport is fragmentary. Here, we systematically measured aspartate uptake rates in proteoliposomes containing purified Glt, and derived the rate equation for a mechanism in which two sodium ions bind before and another after aspartate. Re-analysis of existing data on Glt using this equation allowed for determination of the turnover number (0. Read More

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Untargeted metabolomics and infrared ion spectroscopy identify biomarkers for pyridoxine-dependent epilepsy.

J Clin Invest 2021 Jun 17. Epub 2021 Jun 17.

Institute for Molecules and Materials, FELIX Laboratory, Radboud University Nijmegen, Nijmegen, Netherlands.

Pyridoxine-dependent epilepsy (PDE-ALDH7A1), also known as antiquitin deficiency, is an inborn error of lysine metabolism that presents with refractory epilepsy in newborns. Bi-allelic ALDH7A1 variants lead to deficiency of α-aminoadipic semialdehyde dehydrogenase, resulting in accumulation of piperideine-6-carboxylate (P6C), and secondary deficiency of the important co-factor pyridoxal-5'-phosphate (PLP, active vitamin B6) through its complexation with P6C. Vitamin B6 supplementation resolves epilepsy in patients, but despite this treatment, intellectual disability may occur. Read More

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Enhanced Potassium-Ion Storage of the 3D Carbon Superstructure by Manipulating the Nitrogen-Doped Species and Morphology.

Nanomicro Lett 2020 Oct 27;13(1). Epub 2020 Oct 27.

College of Materials Science and Engineering, Hunan University, Changsha, 410082, People's Republic of China.

Potassium-ion batteries (PIBs) are attractive for grid-scale energy storage due to the abundant potassium resource and high energy density. The key to achieving high-performance and large-scale energy storage technology lies in seeking eco-efficient synthetic processes to the design of suitable anode materials. Herein, a spherical sponge-like carbon superstructure (NCS) assembled by 2D nanosheets is rationally and efficiently designed for K storage. Read More

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October 2020

Two-Dimensional Black Phosphorus Nanomaterials: Emerging Advances in Electrochemical Energy Storage Science.

Nanomicro Lett 2020 Sep 2;12(1):179. Epub 2020 Sep 2.

Collaborative Innovation Center for Optoelectronic Science and Technology, International Collaborative Laboratory of 2D Materials for Optoelectronic Science and Technology of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen, 518060, People's Republic of China.

Two-dimensional black phosphorus (2D BP), well known as phosphorene, has triggered tremendous attention since the first discovery in 2014. The unique puckered monolayer structure endows 2D BP intriguing properties, which facilitate its potential applications in various fields, such as catalyst, energy storage, sensor, etc. Owing to the large surface area, good electric conductivity, and high theoretical specific capacity, 2D BP has been widely studied as electrode materials and significantly enhanced the performance of energy storage devices. Read More

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September 2020

NiCoO Nano-/Microstructures as High-Performance Biosensors: A Review.

Rajesh Kumar

Nanomicro Lett 2020 Jun 8;12(1):122. Epub 2020 Jun 8.

Department of Chemistry, Jagdish Chandra DAV College, Dasuya, Distt. Hoshiarpur, 144205, Punjab, India.

Non-enzymatic biosensors based on mixed transition metal oxides are deemed as the most promising devices due to their high sensitivity, selectivity, wide concentration range, low detection limits, and excellent recyclability. Spinel NiCoO mixed oxides have drawn considerable attention recently due to their outstanding advantages including large specific surface area, high permeability, short electron, and ion diffusion pathways. Because of the rapid development of non-enzyme biosensors, the current state of methods for synthesis of pure and composite/hybrid NiCoO materials and their subsequent electrochemical biosensing applications are systematically and comprehensively reviewed herein. Read More

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MV CBCT-Based Synthetic CT Generation Using a Deep Learning Method for Rectal Cancer Adaptive Radiotherapy.

Front Oncol 2021 31;11:655325. Epub 2021 May 31.

Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.

Due to image quality limitations, online Megavoltage cone beam CT (MV CBCT), which represents real online patient anatomy, cannot be used to perform adaptive radiotherapy (ART). In this study, we used a deep learning method, the cycle-consistent adversarial network (CycleGAN), to improve the MV CBCT image quality and Hounsfield-unit (HU) accuracy for rectal cancer patients to make the generated synthetic CT (sCT) eligible for ART. Forty rectal cancer patients treated with the intensity modulated radiotherapy (IMRT) were involved in this study. Read More

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Computation of distribution of relaxation times by Tikhonov regularization for Li ion batteries: usage of L-curve method.

Sci Rep 2021 Jun 16;11(1):12624. Epub 2021 Jun 16.

Institute of Physics, Academia Sinica, 115, Taipei, Taiwan.

In this paper, the distribution of relaxation times (DRTs) functions are calculated numerically in Matlab for synthetic impedance data from single parallel [Formula: see text] circuit and two parallel [Formula: see text] circuits connected in series, experimental impedance data from supercapacitors and α-LiFeO anode based Li ion batteries. The quality of the impedance data is checked with the Kramers-Krönig (KK) relations. The DRTs are calculated within the KK compatible regime for all the systems using Tikhonov regularization (TR) method. Read More

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Phytotoxicity of the chiral herbicide dichlorprop: Cross-talk between nitric oxide, reactive oxygen species and phytohormones.

Sci Total Environ 2021 Sep 20;788:147866. Epub 2021 May 20.

MOE Key Laboratory of Environmental Remediation & Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China. Electronic address:

Nitric oxide (NO), reactive oxygen species (ROS), and phytohormones in plants often initiate responses to sources of abiotic stress. However, we have a poor understanding of the cross-talk between NO, ROS, and phytohormones during exogenous chiral auxin-induced phytotoxicity. In this study, the toxicity of the chiral synthetic auxin herbicide dichlorprop (DCPP) to Arabidopsis thaliana, as well as the mutual regulation of NO, hydrogen peroxide (HO), superoxide anion (O), and phytohormones at the enantiomeric level was investigated. Read More

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September 2021

Azacytidine plus olaparib for relapsed acute myeloid leukaemia, ineligible for intensive chemotherapy, diagnosed with a synchronous malignancy.

J Cell Mol Med 2021 Jun 16. Epub 2021 Jun 16.

Department of Hematology, Iuliu Hatieganu University of Medicine and Pharmacy Cluj Napoca, Cluj Napoca, Romania.

Patients with relapsed/refractory acute myeloid leukaemia (AML), ineligible for intensive chemotherapy and allogeneic stem cell transplantation, have a dismal prognosis. For such cases, hypomethylating agents are a viable alternative, but with limited success. Combination chemotherapy using a hypomethylating agent plus another drug would potentially bring forward new alternatives. Read More

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Excellent dye degradation performance of FeSiBP amorphous alloys by Fenton-like process.

J Environ Sci (China) 2021 Jul 15;105:116-127. Epub 2021 Jan 15.

Department of Materials Science and Metallurgical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea.

Amorphous alloys are being newly applied in wastewater treatment because of their unique atomic packing structure. They possess excellent degradation efficiency, stability and reusability. In this work, FeSiB and FeSiBP amorphous ribbons exhibited advanced catalytic performance for the degradation of Methyl Blue (MB) and Rhodamine B (RhB) dyes, and the color removal reach nearly 100% within 11 min for both the dyes. Read More

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Solid-State NMR Study to Probe the Effects of Divalent Metal Ions (Ca and Mg) on the Magnetic Alignment of Polymer-Based Lipid Nanodiscs.

Langmuir 2021 Jun 15. Epub 2021 Jun 15.

Biophysics Program and Department of Chemistry, Biomedical Engineering, and Macromolecular Science and Engineering, The University of Michigan, Ann Arbor, Michigan 48109-1055, United States.

Divalent cations, especially Ca and Mg, play a vital role in the function of biomolecules and making them important to be constituents in samples for in vitro biophysical and biochemical characterizations. Although lipid nanodiscs are becoming valuable tools for structural biology studies on membrane proteins and for drug delivery, most types of nanodiscs used in these studies are unstable in the presence of divalent metal ions. To avoid the interaction of divalent metal ions with the belt of the nanodiscs, synthetic polymers have been designed and demonstrated to form stable lipid nanodiscs under such unstable conditions. Read More

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Transmembrane anion transport mediated by halogen bonding and hydrogen bonding triazole anionophores.

Chem Sci 2020 Apr 15;11(18):4722-4729. Epub 2020 Apr 15.

Chemistry Research Laboratory, University of Oxford Mansfield Road Oxford OX1 3TA UK

Transmembrane ion transport by synthetic anionophores is typically achieved using polar hydrogen bonding anion receptors. Here we show that readily accessible halogen and hydrogen bonding 1,2,3-triazole derivatives can efficiently mediate anion transport across lipid bilayer membranes with unusual anti-Hofmeister selectivity. Importantly, the results demonstrate that the iodo-triazole systems exhibit the highest reported activity to date for halogen bonding anionophores, and enhanced transport efficiency relative to the hydrogen bonding analogues. Read More

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Tackling the chemical diversity of microbial nonulosonic acids - a universal large-scale survey approach.

Chem Sci 2020 Feb 24;11(11):3074-3080. Epub 2020 Feb 24.

Department of Biotechnology, Delft University of Technology 2629 HZ Delft The Netherlands

Nonulosonic acids, commonly referred to as sialic acids, are a highly important group of nine-carbon sugars common to all domains of life. They all share biosynthetic and structural features, but otherwise display a remarkable chemical diversity. In humans, sialic acids cover all cells which makes them important for processes such as cellular protection, immunity and brain development. Read More

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February 2020

Catalyst-Controlled Regiodivergence in Rearrangements of Indole-Based Onium Ylides.

J Am Chem Soc 2021 Jun 14;143(24):9016-9025. Epub 2021 Jun 14.

Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States.

We have developed catalyst-controlled regiodivergent rearrangements of onium-ylides derived from indole substrates. Oxonium ylides formed from substituted indoles selectively undergo [2,3]- and [1,2]-rearrangements in the presence of a rhodium and a copper catalyst, respectively. The combined experimental and density functional theory (DFT) computational studies indicate divergent mechanistic pathways involving a metal-free ylide in the rhodium catalyzed reaction favoring [2,3]-rearrangement, and a metal-coordinated ion-pair in the copper catalyzed [1,2]-rearrangement that recombines in the solvent-cage. Read More

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Design of pure heterodinuclear lanthanoid cryptate complexes.

Chem Sci 2021 Apr 15;12(20):6983-6991. Epub 2021 Apr 15.

Department of Chemistry, University of Copenhagen Universitetsparken 5 DK-2100 Copenhagen Denmark

Heterolanthanide complexes are difficult to synthesize owing to the similar chemistry of the lanthanide ions. Consequently, very few purely heterolanthanide complexes have been synthesized. This is despite the fact that such complexes hold interesting optical and magnetic properties. Read More

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Direct observation of the evolving metal-support interaction of individual cobalt nanoparticles at the titania and silica interface.

Chem Sci 2020 Oct 26;11(48):13060-13070. Epub 2020 Oct 26.

Department of Chemistry, University College London 20 Gordon Street London WC1H 0AJ UK

Understanding the metal-support interaction (MSI) is crucial to comprehend how the catalyst support affects performance and whether this interaction can be exploited in order to design new catalysts with enhanced properties. Spatially resolved soft X-ray absorption spectroscopy (XAS) in combination with Atomic Force Microscopy (AFM) and Scanning Helium Ion-Milling Microscopy (SHIM) has been applied to visualise and characterise the behaviour of individual cobalt nanoparticles (CoNPs) supported on two-dimensional substrates (SiO Si(100) ( < 2) and rutile TiO(110)) after undergoing reduction-oxidation-reduction (ROR). The behaviour of the Co species is observed to be strongly dependent on the type of support. Read More

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October 2020

Mechanism and origins of selectivity in the enantioselective oxa-Pictet-Spengler reaction: a cooperative catalytic complex from a hydrogen bond donor and chiral phosphoric acid.

Chem Sci 2020 Jul 27;11(33):8736-8743. Epub 2020 Jul 27.

Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Northwestern University Evanston IL 60208 USA

Enantioselective additions to oxocarbenium ions are high-value synthetic transformations but have proven challenging to achieve. In particular, the oxa-Pictet-Spengler reaction has only recently been rendered enantioselective. We report experimental and computational studies on the mechanism of this unusual transformation. Read More

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A new soft-matter material with old chemistry: Passerini multicomponent polymerization-induced assembly of AIE-active double-helical polymers with rapid visible-light degradability.

Chem Sci 2020 Jul 15;11(31):8224-8230. Epub 2020 Jul 15.

Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University Xi'an China

Mimicking the superstructures and functions of natural chiral materials is beneficial to understand specific biological activities in living organisms and broaden applications in the fields of chemistry and materials sciences. However, it is still a great challenge to construct water-soluble, double-helical polymers with multiple responsiveness. Herein, we report for the first time a straightforward, general strategy to address this issue by taking advantage of Passerini multicomponent polymerization-induced assembly (PMPIA). Read More

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Optogenetic control of calcium influx in mammalian cells.

Methods Enzymol 2021 16;654:255-270. Epub 2021 Mar 16.

Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M University, Houston, TX, United States. Electronic address:

Optogenetics combines optics and genetics to enable non-invasive interrogation of cell physiology at an unprecedented high spatiotemporal resolution. Here, we introduce Opto-CRAC as a set of genetically-encoded calcium actuators (GECAs) engineered from the calcium release-activated calcium (CRAC) channel, which has been tailored for optical control of calcium entry and calcium-dependent physiological responses in non-excitable cells and tissues. We describe a detailed protocol for applying Opto-CRAC as an optogenetic tool to achieve photo-tunable control over intracellular calcium signals and calcium-dependent gene expression in mammalian cells. Read More

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Ion channel engineering using protein trans-splicing.

Methods Enzymol 2021 27;654:19-48. Epub 2021 Feb 27.

Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark. Electronic address:

Conventional site-directed mutagenesis and genetic code expansion approaches have been instrumental in providing detailed functional and pharmacological insight into membrane proteins such as ion channels. Recently, this has increasingly been complemented by semi-synthetic strategies, in which part of the protein is generated synthetically. This means a vast range of chemical modifications, including non-canonical amino acids (ncAA), backbone modifications, chemical handles, fluorescent or spectroscopic labels and any combination of these can be incorporated. Read More

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February 2021