Integrating dynamic DNA nanotechnology with protein‐controlled actuation will expand our ability to process molecular information. We have developed a strategy to actuate strand displacement reactions using DNA‐binding proteins by engineering synthetic DNA translators that convert specific protein‐binding events into trigger inputs through a programmed conformational change. We have constructed synthetic DNA networks responsive to two different DNA‐binding proteins, TATA‐binding protein and Myc‐Max,...
Sat Aug 01, 2020 11:35
The biological applications of germylenes remain unrealised owing to their unstable nature. We report the isolation of air, water, and culture‐medium stable germylene DPMGeOH (3) and its potential biological application (DPM = dipyrromethene ligand). Compound 3 exhibits antiproliferative effects comparable to that of cisplatin in human cancer cells. The cytotoxicity of compound 3 on normal epithelial cells is minimal and is similar to that of the currently used anticancer drugs. These findings provide...
Fri Jul 31, 2020 21:33
The geometry of reaction compartments can affect the local outcome of interface‐restricted reactions. Giant unilamellar vesicles (GUVs) are commonly used to generate cell‐sized, membrane‐bound reaction compartments, which are, however, always spherical. Here, we have developed a microfluidic chip to trap and reversibly deform GUVs into cigar‐like shapes. When trapping and elongating GUVs that contain the primary protein of the bacterial Z ring, FtsZ, we find that membrane‐bound FtsZ filaments align...
Fri Jul 31, 2020 20:09
The efficacy of photodynamic therapy is typically reliant on the local concentration and diffusion of oxygen. Due to the hypoxic microenvironment found in solid tumors, oxygen‐independent photosensitizers are in great demand for cancer therapy. We herein report an iridium(III) anthraquinone complex (Ir4) as a mitochondrion‐localized carbon radical initiator. The emission of Ir4 is turned‐on under hypoxic conditions after reduction by reductase. Furthermore, the two‐photon excitation properties of...
Fri Jul 31, 2020 19:04
The selective formal insertion (homologation) of a carbon unit bridging the two trifluoroacetamidoyl chlorides (TFAICs) units is reported. The tactic is levered on a highly chemoselective homologation – metalation – acyl nucleophilic substitution sequence which precisely enables to assemble novel trifluoromethylated β‐diketiminates within a single synthetic operation. Unlike previous homologations conducted with LiCH 2 Cl furnishing aziridines, herein we exploit the unique capability of iodomethyllithium...
Fri Jul 31, 2020 18:34
Scanning electrochemical microscopy (SECM) is one of the most important instrumental methods of modern electrochemistry, due to its high spatial and temporal resolution. Here, we introduce SECM into nanomachining by feeding the electrochemical modulations of the tip electrode back to the positioning system, and we demonstrate that SECM is qualified to be a versatile nanomachining technique on semiconductor wafers using electrochemically‐induced chemical etching. The removal profile is correlated...
Fri Jul 31, 2020 17:33
Many properties of intrinsically disordered proteins (IDPs) or protein regions (IDRs) are expected to be modulated by the nature of amino acid side chains as well as by local solvent exposure. Here we propose a set of exclusively heteronuclear NMR experiments to investigate these features in different experimental conditions relevant for physiological function. The proposed approach is generally applicable to many IDPs/IDRs whose assignment is available in the BMRB to investigate how their properties...
Fri Jul 31, 2020 17:03
High throughput (HT) enzymatic assays, which typically rely on labeled compounds and plate readers, are important for drug discovery. Mass spectrometry (MS) provides an alternative method of performing HT label‐free assays. Here we demonstrate the use of a HT platform based on desorption electrospray ionization (DESI) MS for the label‐free study of enzymatic reactions directly from the bioassay matrix, with an effective analysis time of 0.3 s/sample. This system allows for thorough analysis of the...
Fri Jul 31, 2020 16:03
A straightforward quantification method to consistently determine the overall functionalization degree of covalently modified two‐dimensional (2D) black phosphorus (BP) by Raman spectroscopy has been carried out. Indeed, the successful reductive methylation of the BP lattice using sodium intercalation compounds and exhibiting different functionalization degrees has been demonstrated by 31 P‐magic angle spinning (MAS) NMR spectroscopy. Furthermore, the correlation of 31 P‐MAS NMR spectroscopy...
Fri Jul 31, 2020 14:05
Through phosphorus doping , the charge distribution in Fe‐Ni layered double hydroxide (LDH) is regulated to promote the activation of nitrogen. This strategy offers an opportunity of tapping the unknown potentials of the well‐known hydrotalcites (LDHs) in the field of electrocatalytic nitrogen fixation. Abstract The key to bringing the electrocatalytic nitrogen fixation from conception to application lies in the development of high‐efficiency, cost‐effective electrocatalysts. Layered double...
Fri Jul 31, 2020 13:12
The use of cyclopentadienyl ligands in organometallic chemistry and catalysis is ubiquitous, mostly due to their robust spectator role. Nonetheless, increasing examples of non‐innocent behaviour are being documented. Here, we provide evidence for reversible intramolecular C—H activation at one methyl terminus of C 5 Me 5 in [( η ‐C 5 Me 5 )Rh(PMe 3 ) 2 ] to form a new Rh—H bond, a process so far restricted to early transition metals. Experimental proof was acquired from bimetallic rhodium/gold...
Fri Jul 31, 2020 11:03
The gut pathogen Clostridium bolteae has been associated with the onset of autism spectrum disorder (ASD). To create vaccines against C. bolteae , it is important to identify exact protective epitopes of the immunologically active capsular polysaccharide (CPS). Here, we prepared a series of C. bolteae CPS glycans up to an octadecasaccharide. Key to achieving the total syntheses is a [2+2] coupling strategy based on a β‐d‐Rha p ‐(1→3)‐α‐d‐Man p repeating unit that in turn was accessed via...
Fri Jul 31, 2020 10:53
We exploit the possible link between structural surface roughness and difficulty of crystallisation. Polymorphs with smooth surfaces may nucleate and crystallise easier than polymorphs with rough surfaces. The concept is applied to crystal structure prediction landscapes and reveals a promising complementary way of ranking putative crystal structures.
Thu Jul 30, 2020 22:00
Unpredictable in vivo therapeutic feedback of hydroxyl radical (•OH) efficiency is the major bottleneck of chemodynamic therapy. Herein, we describe novel Fenton‐based nanotheranostics NQ‐Cy@Fe&GOD for spatio‐temporally reporting intratumor •OH‐mediated treatment, which innovatively unites dual‐channel near‐infrared (NIR) fluorescence and magnetic resonance imaging (MRI) signals. Specifically, MRI signal traces the dose distribution of Fenton‐based iron oxide nanoparticles (IONPs) with high‐spatial...
Thu Jul 30, 2020 16:07
This study demonstrates for the first time that easily accessible transition metal acylnitrenoids can be used for controlled direct C(sp 3 )‐H oxygenations. Specifically, a ruthenium catalyst activates N‐benzoyloxycarbamates as nitrene precursors towards regioselective intramolecular C‐H oxygenations to provide cyclic carbonates, hydroxylated carbamates, or 1,2‐diols. The method can be applied to the chemoselective C‐H oxygenation of benzylic, allylic, and propargylic C(sp 3 )‐H bonds. The reaction...
Thu Jul 30, 2020 16:06
The enantioselective desymmetrizing C–H activation of α‐ gem‐ dialkyl acyclic amides remains challenging because the availability of four chemically identical unbiased methylene C(sp 3 )‐H bonds and increased rotational freedoms of the acyclic systems add tremendous difficulties for chemo‐ and stereocontrol. Herein, we develop the synthesis of acyclic aliphatic amides with α ,β‐ contiguous stereogenic centers via Pd(II)‐catalyzed asymmetric arylation of unbiased methylene C(sp 3 )–H in good...
Thu Jul 30, 2020 15:11
Reaction of an Al‐centered anion with toluene proceeded to form C–H cleaved product with a perfect meta ‐selectivity and a relatively small kinetic isotope effect (KIE, k H / k D = 1.51). DFT calculations suggested a two‐step reaction mechanism and electronically controlled meta ‐selectivity arising from the electron‐donating methyl group. The reaction with other mono‐substituted arenes was also investigated.
Thu Jul 30, 2020 15:11
Good as gold : The novel alkynyl phosphane AuI complex 1 displays multiple biological activites including selective proliferation inhibitory, anti‐metastatic, and anti‐angiogenic effects. The complex also induced effects related to aneuploidy in colon carcinoma cells, which may provide an effective strategy to target cancer. Abstract A novel alkynyl phosphane gold(I) complex (trimethylphosphane)(3‐(1,3‐dimethylxanthine‐7‐yl)prop‐1‐yn‐1‐yl)gold(I) 1 displayed mutiple biological activites...
Thu Jul 30, 2020 12:34
Targeted protein degradation has created tremendous excitement in chemical biology and drug discovery. This Review gives a comprehensive overview of chemical biology tools as well as therapeutic approaches inducing targeted protein degradation and discusses them from a medicinal chemist's perspective. Abstract Targeted protein degradation (TPD), the ability to control a proteins fate by triggering its degradation in a highly selective and effective manner, has created tremendous excitement...
Thu Jul 30, 2020 12:34
Making it stick : The design and synthesis of amino‐catechol adhesives by copolymerization of traditional monomers with mussel‐inspired monomers is presented. The coexistence of catechol and amine moieties in a hybrid monomer architecture can lead to optimization of the overall performance of the catechol–amine adhesives and the development of pressure‐sensitive adhesives with remarkable resistance to flow under shear. Abstract The outstanding adhesive performance of mussel byssal threads...
Thu Jul 30, 2020 12:29
CoIII‐catalyzed site‐selective C8−H activation of quinoline N‐oxides is demonstrated, engaging allenes as dienylation partners under relatively mild reaction conditions. The combination of a carbonate leaving group on the allene and 30 mol % of a NaF additive was found to be crucial for the dienylation reaction with a broad range of quinoline N‐oxides and allenes, including late‐stage functionalizations. Mechanistic studies provide key insights into the reaction mechanism. Abstract An...
Thu Jul 30, 2020 12:20
Unique ruthenium–cobalt oxide [(Ru–Co)O x ] hollow nanosheet arrays with an inter‐doped heterostructure are prepared on carbon cloth via a facile MOF template‐based strategy. The (Ru–Co)O x nanoarrays exhibit excellent catalytic activity for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), indicating an outstanding bifunctional electrocatalyst for alkaline overall water splitting. Abstract The development of transition‐metal‐oxides (TMOs)‐based...
Thu Jul 30, 2020 12:19
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου