Read by QxMD icon Read

Click chemistry

Leah M Seebald, Christopher M DeMott, Srivathsan Ranganathan, Papa Nii Asare Okai, Anastasia Glazunova, Alan Chen, Alexander Shekhtman, Maksim Royzen
Paramagnetic NMR techniques allow for studying three-dimensional structures of RNA-protein complexes. In particular, paramagnetic relaxation enhancement (PRE) data can provide valuable information about long-range distances between different structural components. For PRE NMR experiments, oligonucleotides are typically spin-labeled using nitroxide reagents. The current work describes an alternative approach involving a Cu(II) cyclen-based probe that can be covalently attached to an RNA strand in the vicinity of the protein's binding site using "click" chemistry...
March 22, 2017: Inorganic Chemistry
Victor Garcia, Ankit Gilani, Brian Shkolnik, Varunkumar Pandey, Frank F Zhang, Rambabu Dakarapu, Shyam K Gandham, N R Reddy, Joan P Graves, Artiom Gruzdev, Darryl C Zeldin, Jorge H Capdevila, John R Falck, Michal L Schwartzman
Rationale: 20-Hydroxyeicosatetraenoic acid (20-HETE), one of the principle cytochrome P450 (CYP) eicosanoids, is a potent vasoactive lipid whose vascular effects include stimulation of smooth muscle contractility, migration and proliferation, as well as endothelial cell dysfunction and inflammation. Increased levels of 20-HETE in experimental animals and in humans are associated with hypertension, stroke, myocardial infarction and vascular diseases. Objective: To date, a receptor/binding site for 20-HETE has been implicated based on the use of specific agonists and antagonists...
March 21, 2017: Circulation Research
Nicholas G Welch, Judith A Scoble, Benjamin W Muir, Paul J Pigram
Orientation of surface immobilized capture proteins, such as antibodies, plays a critical role in the performance of immunoassays. The sensitivity of immunodiagnostic procedures is dependent on presentation of the antibody, with optimum performance requiring the antigen binding sites be directed toward the solution phase. This review describes the most recent methods for oriented antibody immobilization and the characterization techniques employed for investigation of the antibody state. The introduction describes the importance of oriented antibodies for maximizing biosensor capabilities...
March 16, 2017: Biointerphases
Aline Mongis, Friedrich Piller, Véronique Piller
The present study investigated the potential of metabolic glycoengineering followed by bioorthogonal click chemistry for introducing into cell surface glycans different immunomodulating molecules. Mouse tumor models EG7 and MC38-OVA were treated with Ac4GalNAz and Ac4ManNAz followed by ligation of immunostimulants to modified cell surface glycans of the living cells through bioorthogonal click chemistry. The presence of covalently bound oligosaccharide and oligonucleotide immunostimulants could be clearly established...
March 15, 2017: Bioconjugate Chemistry
Uwe Bog, Andrés de Los Santos, Summer Mueller, Shana Havenridge, Viviana Parrillo, Michael Bruns, Andrea E Holmes, Cesar Rodriguez-Emmenegger, Harald Fuchs, Michael Hirtz
Protein-repellent reactive surfaces that promote localized specific binding are highly desirable for applications in the biomedical field. Nonspecific adhesion will compromise the function of bioactive surfaces, leading to ambiguous results of binding assays and negating the binding specificity of patterned cell-adhesive motives. Localized specific binding is often achieved by attaching a linker to the surface and the other side of the linker is used to bind specifically to a desired functional agent, as e...
March 15, 2017: ACS Applied Materials & Interfaces
Ivan Zemskov, Stefan Altaner, Daniel R Dietrich, Valentin Wittmann
Microcystins (MCs) are highly toxic natural products which are produced by cyanobacteria. They can be released to the water during harmful algal blooms and are a serious threat to animals and humans. Described is the total synthesis of the cyanotoxin microcystin-LF (MC-LF, 1a) and two derivatives thereof. Deuterated derivative 1b is of interest as an internal standard during MC quantification in biological samples by mass spectrometry and alkyne-labeled 1c can be employed for toxin derivatization by click chemistry with an azide-containing reporter molecule or as an activity-based probe to identify interaction partners...
March 15, 2017: Journal of Organic Chemistry
Haiming Luo, Christopher G England, Shreya Goel, Stephen A Graves, Fanrong Ai, Bai Liu, Charles P Theuer, Hing C Wong, Robert J Nickles, Weibo Cai
Dual-targeted imaging agents have shown improved targeting efficiencies in comparison to single-targeted entities. The purpose of this study was to quantitatively assess the tumor accumulation of a dual-labeled heterobifunctional imaging agent, targeting two overexpressed biomarkers in pancreatic cancer, using positron emission tomography (PET) and near-infrared fluorescence (NIRF) imaging modalities. A bispecific immunoconjugate (heterodimer) of CD105 and tissue factor (TF) Fab' antibody fragments was developed using click chemistry...
March 14, 2017: Molecular Pharmaceutics
Maria Taskova, Charlotte S Madsen, Knud J Jensen, Lykke Haastrup Hansen, Birte Vester, Kira Astakhova
Specific target binding and stability in diverse biological media is of crucial importance for applications of synthetic oligonucleotides as diagnostic and therapeutic tools. So far, these issues have been addressed by chemical modification of oligonucleotides and by conjugation with a peptide, most often at the terminal position of the oligonucleotide. Herein, we for the first time systematically investigate the influence of internally attached short peptides on the properties of antisense oligonucleotides...
March 15, 2017: Bioconjugate Chemistry
Aleksandra Michalik-Onichimowska, Simon Kern, Jens Riedel, Ulrich Panne, Rudibert King, Michael Maiwald
Driven mostly by the search for chemical syntheses under biocompatible conditions, so called "click" chemistry rapidly became a growing field of research. The resulting simple one-pot reactions are so far only scarcely accompanied by an adequate optimization via comparably straightforward and robust analysis techniques possessing short set-up times. Here, we report on a fast and reliable calibration-free online NMR monitoring approach for technical mixtures. It combines a versatile fluidic system, continuous-flow measurement of (1)H spectra with a time interval of 20s per spectrum, and a robust, fully automated algorithm to interpret the obtained data...
March 1, 2017: Journal of Magnetic Resonance
Oleg V Kulikov, Dumindika A Siriwardane, Gregory T McCandless, Samsuddin F Mahmood, Bruce M Novak
A facile method for the preparation of polycarbodiimide-based secondary structures (e.g., nano-rings, "craters," fibers, looped fibers, fibrous networks, ribbons, worm-like aggregates, toroidal structures, and spherical particles) is described. These aggregates are morphologically influenced by extensive hydrophobic side chain-side chain interactions of the singular polycarbodiimide strands, as inferred by atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques. Polycarbodiimide-g-polystyrene copolymers (PS-PCDs) were prepared by a combination of synthetic methods, including coordination-insertion polymerization, copper(I)-catalyzed azide alkyne cycloaddition (CuAAC) "click" chemistry, and atom transfer radical polymerization (ATRP)...
February 7, 2017: Journal of Visualized Experiments: JoVE
Lisa M Meints, Anne W Poston, Brent F Piligian, Claire D Olson, Katherine S Badger, Peter J Woodruff, Benjamin M Swarts
Chemically modified versions of trehalose, or trehalose analogues, have applications in biology, biotechnology, and pharmaceutical science, among other fields. For instance, trehalose analogues bearing detectable tags have been used to detect Mycobacterium tuberculosis and may have applications as tuberculosis diagnostic imaging agents. Hydrolytically stable versions of trehalose are also being pursued due to their potential for use as non-caloric sweeteners and bioprotective agents. Despite the appeal of this class of compounds for various applications, their potential remains unfulfilled due to the lack of a robust route for their production...
February 17, 2017: Journal of Visualized Experiments: JoVE
Jens Christoffers, Melanie Wallisch, Stefan Sulmann, Karl-Wilhelm Koch
Diaminoterephthalates are fluorescent dyes and define scaffolds which can be orthogonally functionalized at their two carboxylate residues with functional residues bearing task specific reactive groups. The synthesis of monofunctionalized dyes with thiol groups for surface binding, an azide for click chemistry and a biotinoylated congener for streptavidin binding is reported. Two bifunctionalized dyes were prepared: One with an azide for click chemistry and a biotin for streptavidin binding, the other with a maleimide for reaction with thiol and a cyclooctyne moiety for ligation with copper-free click chemistry...
March 9, 2017: Chemistry: a European Journal
Claudia Ferroni, Antonella Pepe, Yeong Sang Kim, Sunmin Lee, Andrea Guerrini, Marco Daniele Parenti, Anna Tesei, Alice Zamagni, Michela Cortesi, Nadia Zaffaroni, Michelandrea De Cesare, Giovanni Luca Beretta, Jane B Trepel, Sanjay V Malhotra, Greta Varchi
Prostate cancer (PC) is the fifth leading cause of cancer death in men, and the androgen receptor (AR) represents the primary target for PC treatment, even though the disease frequently progresses toward androgen-independent forms. Most of the commercially available nonsteroidal antiandrogens show a common scaffold consisting of two aromatic rings connected by a linear or a cyclic spacer. By taking advantage of a facile, one-pot click chemistry reaction, we report herein the preparation of a small library of novel 1,4-substituted triazoles with AR antagonistic activity...
March 20, 2017: Journal of Medicinal Chemistry
Monalisa Mukherjee, Satyendra K Rajput, Deepa Suhag, Apoorv Gupta, Aarti Singh, Vipin Kumar, Adeeba Shakeel, Arun Kumar Sharma, Nameet Kaur
In recent years, several scientific investigations have reported the therapeutic implications of superoxide dismutase (SOD) against oxidative stress and -induced pathology in clinical and preclinical trials. Indeed, various kinase, molecular signaling and physiological process has altered by reactive oxygen species. In spite of the abundant available literature reports, patents, clinical trials and commercialized products, the therapeutic application of SOD as a potential drug still remains unclear. Owing to the technical challenges associated with the utilization of SOD as a drug, we revisited the structural arrangement and cellular signaling, significant association with kinase which exploring the new target sites and introduction of new formulation strategies such as gene modulation, nano-formulations and click chemistry is a prerequisite...
March 7, 2017: Current Topics in Medicinal Chemistry
Jingfen Han, Xia Wang, Lixia Liu, Dongxue Li, Suyaola Suyaola, Tianyue Wang, Huricha Baigude
A cationic group has been quantitatively and selectively introduced into C6 position of each glucose units of Curdlan by "Click Chemistry" successfully. The resulting cationic Curdlan-Imidazole-lysine polymers (Cur-6-100Lys) exhibit excellent water solubility. Structure of the Cur-6-100Lys complexes was verified by FTIR and NMR spectroscopic measurements, and analysis of Cur-6-100Lys by GPC, DLS and SEM revealed that they have stoichiometric, nanosized spheroidal structures. Cytotoxicity measurement, electrophoretic mobility shift assay and EGFP-pDNA transfection have been carried out respectively...
May 1, 2017: Carbohydrate Polymers
Xiangang Huang, Diana Andina, Jingshui Ge, Anne Labarre, Jean-Christophe Leroux, Bastien Castagner
Calcium phosphate (CaP) nanoparticles are promising gene delivery carriers due to their bioresorbability, ease of preparation, high gene loading efficacy, and endosomal escape properties. However, the rapid aggregation of the particles needs to be addressed in order to have potential in vivo. In addition, there is a need to better understand the relationship between CaP nanoparticle properties and their interactions with cells. Here, a new synthesis route involving click chemistry was developed to prepare the PEGylated chelator PEG-inositol 1,3,4,5,6-pentakisphosphate (PEG-IP5) that can coat and stabilize CaP nanoparticles...
March 14, 2017: ACS Applied Materials & Interfaces
Mariano Walter Pertino, Celeste Vega, Miriam Rolón, Cathia Coronel, Antonieta Rojas de Arias, Guillermo Schmeda-Hirschmann
Tropical parasitic diseases such as Chagas disease and leishmaniasis are considered a major public health problem affecting hundreds of millions of people worldwide. As the drugs currently used to treat these diseases have several disadvantages and side effects, there is an urgent need for new drugs with better selectivity and less toxicity. Structural modifications of naturally occurring and synthetic compounds using click chemistry have enabled access to derivatives with promising antiparasitic activity. The antiprotozoal activity of the terpenes dehydroabietic acid, dehydroabietinol, oleanolic acid, and 34 synthetic derivatives were evaluated against epimastigote forms of Trypanosoma cruzi and promastigotes of Leishmaniabraziliensis and Leishmania infantum...
February 28, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Brian J F Swift, Jared A Shadish, Cole A DeForest, François Baneyx
Combining bioorthogonal chemistry with the use of proteins engineered with adhesive and morphogenetic solid-binding peptides is a promising route for synthesizing hybrid materials with the economy and efficiency of living systems. Using optical sensing of chloramphenicol as a proof of concept, we show here that a GFP variant engineered with zinc sulfide and silica-binding peptides on opposite sides of its β-barrel supports the fabrication of protein-capped ZnS:Mn nanocrystals that exhibit the combined emission signatures of organic and inorganic fluorophores...
March 13, 2017: Journal of the American Chemical Society
Mohiuddin A Quadir, Stephen W Morton, Lawrence B Mensah, Kevin Shopsowitz, Jeroen Dobbelaar, Nicole Effenberger, Paula T Hammond
A ligand decorated, synthetic polypeptide block copolymer platform with environment-responsive capabilities was designed. We evaluated the potential of this system to function as a polymersome for targeted-delivery of a systemic chemotherapy to tumors. Our system employed click chemistry to provide a pH-responsive polypeptide block that drives nanoparticle assembly, and a ligand (folic acid) conjugated PEG block that targets folate-receptor over-expressing cancer cells. These nanocarriers were found to encapsulate a high loading of conventional chemotherapeutics (e...
March 2, 2017: Nanomedicine: Nanotechnology, Biology, and Medicine
Katharina Schmid, Maria Adobes-Vidal, Mark Helm
Bioconjugation of RNA is a dynamic field recently reinvigorated by a surge in research on posttranscriptional modification. This work focusses on the bioconjugation of 4-thiouridine, a nucleoside that occurs as a post-transcriptional modification in bacterial RNA, and is used as a metabolic label and for crosslinking purposes in eukaryotic RNA. A newly designed coumarin compound, named 7-propargyloxy-4-bromomethylcoumarin (PBC) is introduced, which exhibits remarkable selectivity for 4-thiouridine. Bearing a terminal alkyne group, it is conductive to secondary bioconjugation via "click chemistry", thereby offering a wide range of preparative and analytical options...
March 6, 2017: Bioconjugate Chemistry
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"