Read by QxMD icon Read

electrostatic ligand

Zhe Li, Lianying Wang, Zenghe Li, Rui Tian, Chao Lu
Fenton/Fenton-like reaction is often used as an efficient method to generate hydroxyl radicals (HO) for bacteria inactivation in aqueous solution. However, inactivation efficiency of bacteria in aqueous solution using Fenton/Fenton-like reactions needs to further improve as a result of transient generation of HO. In this paper, we found that the formation of Tris-Co(II) complexes could decrease the redox potential of Co(III)/Co(II), facilitating the transformation of Tris-Co(III) complexes into Tris-Co(II) complexes...
February 12, 2019: Journal of Hazardous Materials
Li Wang, Coucong Gong, Xinzhu Yuan, Gang Wei
Biomolecular self-assembly provides a facile way to synthesize functional nanomaterials. Due to the unique structure and functions of biomolecules, the created biological nanomaterials via biomolecular self-assembly have a wide range of applications, from materials science to biomedical engineering, tissue engineering, nanotechnology, and analytical science. In this review, we present recent advances in the synthesis of biological nanomaterials by controlling the biomolecular self-assembly from adjusting internal interactions and external stimulations...
February 18, 2019: Nanomaterials
Xue Luan, Kamil Rahme, Zhongcheng Cong, Limei Wang, Yifang Zou, Yan He, Hao Yang, Justin D Holmes, Caitriona M O'Driscoll, Jianfeng Guo
Small interfering RNA (siRNA) has recently illustrated therapeutic potential for malignant disorders. However, the clinical application of siRNA-based therapeutics is significantly retarded by the paucity of successful delivery systems. Recently, multifunctional gold nanoparticles (AuNPs) as non-viral delivery carriers have shown promise for transporting chemotherapeutics, proteins/peptides, and genes. In this study, AuNPs capped with polyethylenimine (PEI) and PEGylated anisamide (a ligand known to target the sigma receptor) have been developed to produce a range of positively charged anisamide-targeted PEGylated AuNPs (namely Au-PEI-PEG-AA)...
February 16, 2019: European Journal of Pharmaceutics and Biopharmaceutics
Nina Slyusarenko, Marina Gerasimova, Alexei Plotnikov, Nikolai Gaponik, Evgenia Slyusareva
The photoluminescence (PL) properties of composites obtained by embedding green-emitting semiconductor nanocrystals (NCs) of two different types (thiol-capped CdTe and CdSe/ZnS) into chitosan-based biopolymer particles were investigated. The synthesis of self-assembled particles from oppositely charged polysaccharides involved a preliminary electrostatic binding of positively charged chitosan chains by negatively charged functional groups of NC stabilizing ligands. The amount of NCs and the acidity of the solution were found to be important parameters influencing the PL...
February 18, 2019: Physical Chemistry Chemical Physics: PCCP
Eliana Karina Asciutto, Sergei Kopanchuk, Anni Lepland, Lorena Simón-Gracia, Carlos Alemán, Tambet Teesalu, Pablo Scodeller
We recently identified a tumor homing peptide (mUNO, sequence: "CSPGAK") that specifically interacts with mouse CD206 to target CD206/MRC1-expressing tumor-associated macrophages in mice. Here, we report studies on the binding of mUNO to human recombinant CD206 (hCD206) and on modeling the mUNO/hCD206 interaction by computational analysis. Fluorescence anisotropy analysis demonstrated that fluorophore-labeled mUNO interacts with hCD206. Microsecond timescale molecular dynamic simulations and docking predictions showed that mUNO binds to a newly identified epitope between C-type lectin domains 1 and 2...
February 15, 2019: Journal of Physical Chemistry. B
Isuru R Ariyarathna, Evangelos Miliordos
Bonding mechanisms, potential energy curves, accurate structures, energetics, and electron affinities are obtained for all M(CX)1-3 species with M = Li, Na, and X = O, S, Se, Te, and Po, at the coupled-cluster level with triple-ζ quality basis sets. We discuss and rationalize the trends within different molecular groups. For example, we found larger binding energies for M = Li, for CX = CPo, and for the tri-coordinated (n = 3) complexes. All three facts are explained by the fact that the global minimum of the titled complexes originate from the first excited 2 P (2p1 for Li or 3p1 for Na) state of the metal, with each ligand forming a dative bond with the metal...
February 12, 2019: Journal of Computational Chemistry
Venubabu Kotikam, Scott D Kennedy, James A MacKay, Eriks Rozners
The development of new RNA-binding ligands is attracting increasing interest in fundamental science and the pharmaceutical industry. The goal of this study was to improve the RNA binding properties of triplex-forming PNAs by further increasing the pKa of 2-aminopyridine (M). Protonation of M was the key for enabling triplex formation at physiological pH in our earlier studies. Substitution on M by an electron donating 4-methoxy substituent resulted in slight destabilization of the PNA-dsRNA triplex, contrary to expected stabilization due to more favorable protonation...
February 11, 2019: Chemistry: a European Journal
Liang Zhang, Alexander J Stephens, Jean-François Lemonnier, Lucian Pirvu, Inigo J Vitorica-Yrezabal, Christopher J Robinson, David A Leigh
The binding of Zn(II) cations to a pentafoil (51) knotted ligand allows the synthesis of otherwise inaccessible metallated molecular pentafoil knots via transmetallation, affording the corresponding 'first sphere' coordination Co(II), Ni(II) and Cu(II) pentanuclear knots in good yields (≥85 %). Each of the knot complexes was characterized by mass spectrometry, the diamagnetic (zinc) knot complex was characterized by 1H and 13C NMR spectroscopy, and the zinc, cobalt and nickel pentafoil knots afforded single crystals whose structures were determined by X-ray crystallography...
February 11, 2019: Journal of the American Chemical Society
Erli Lu, Saira Sajjad, Victoria E J Berryman, Ashley J Wooles, Nikolas Kaltsoyannis, Stephen T Liddle
FEUDAL (f's essentially unaffected, d's accommodate ligands) is a longstanding bonding model in actinide chemistry, in which metal-ligand binding uses 6d-orbitals, with the 5f remaining non-bonding. The inverse-trans-influence (ITI) is a case where the model may break down, and it has been suggested that ionic and covalent effects work synergistically in the ITI. Here, we report an experimentally grounded computational study that quantitatively explores the ITI, and in particular the structure-directing role of f-orbital covalency...
February 7, 2019: Nature Communications
Alexandra Naß, David Schaller, Gerhard Wolber
For drug design projects it is essential to rationally induce and explain selectivity. In this context shape complementarity as well as protein and ligand flexibility represent important factors. Currently available tools for the analysis of protein-ligand interactions focus mainly on electrostatic complementarity and/or static structures. Here we address the shortcomings of available methods by presenting two new tools: The first one can be used to assess steric complementarity in flexible protein-ligand complexes in order to explain selectivity of known ligands...
February 6, 2019: Molecular Informatics
Vishal Das, Sourya Bhattacharya, Channakeshavaiah Chikkaputtaiah, Saugata Hazra, Mintu Pal
Epithelial-mesenchymal transition (EMT) is a key step in transdifferentiation process in solid cancer development. Forthcoming evidence suggest that the stratified program transforms polarized, immotile epithelial cells to migratory mesenchymal cells associated with enhancement of breast cancer stemness, metastasis, and drug resistance. It involves primarily several signaling pathways, such as transforming growth factor-β (TGF-β), cadherin, notch, plasminogen activator protein inhibitor, urokinase plasminogen activator, and WNT/beta catenin pathways...
February 5, 2019: Journal of Cellular Physiology
Garima Sharma, Ashish R Sharma, Sang-Soo Lee, Manojit Bhattacharya, Ju-Suk Nam, Chiranjib Chakraborty
The blood brain barrier (BBB) offers protection to the central nervous system (CNS) by maintaining homeostasis. Besides restricting the entry of harmful xenobiotics and endogenous molecules to CNS, BBB also limits the entry of therapeutic agents. Nanotechnology offers the possibility to deliver small molecules/drugs against CNS disorders across BBB. Recently, due to excellent biocompatibility, functional versatility and unique surface electrostatics properties nanodiamonds are also being explored for their drug delivery potential against BBB...
February 2, 2019: International Journal of Pharmaceutics
Yuxiang Chen, Fang Ma, Xin Chen, Yuehong Zhang, Hailong Wang, Kang Wang, Dongdong Qi, Hao-Ling Sun, Jianzhuang Jiang
For the purpose of further exploring the effect of nonperipherally attached substituents on single-ion magnet (SIMs) performance, tetrasubstituted bis[1,8,15,22-tetrakis(3-pentyloxy)phthalocyaninato]terbium double-deckers, in both the reduced form TbH[Pc(α-OC5 H11 )4 ]2 (1) and the neutral form Tb[Pc(α-OC5 H11 )4 ]2 (2), were prepared. Single-crystal X-ray diffraction analysis for 2 unambiguously demonstrates the pinwheellike molecular structure with C4 symmetry. Magnetic investigations of the two bis(phthalocyaninato)terbium double-deckers reveal their characteristic SIM nature...
February 5, 2019: Inorganic Chemistry
Wei Zhu, Achraf Noureddine, Jane Y Howe, Jimin Guo, C Jeffrey Brinker
Supported ultrasmall noble metal nanocluster-based (UNMN-based) catalysts are one of the most important classes of solid materials for heterogeneous catalysis. In this work, we present a novel strategy for the controlled synthesis of ligand-free UNMN nanocatalysts based on in situ reduction of a palladium-based (Pd-based) metal-organic cage (MOC) confined within monosized, thiol-modified mesoporous silica nanoparticle (MSN) supports. By taking advantage of the high mutual solubility of MOCs and MSNs in DMSO and the strong interactions between the thiol-modified MSN pore wall and MOC surface, a good dispersion of MOC molecules was achieved throughout the MSN support...
February 8, 2019: Nano Letters
Hideshi Yokoyama, Ryuta Mizutani, Shuji Noguchi, Naoki Hayashida
DNA photoproducts with (6-4) pyrimidine-pyrimidone adducts produced by ultraviolet light are mutagenic and carcinogenic. The crystal structures of the anti-(6-4) photoproduct antibody 64M-5 Fab and of its complex with dT(6-4)T were determined at 2.5 and 2.0 Å resolution, respectively. A comparison between the dT(6-4)T-liganded and unliganded structures indicates that the side chain of His93L is greatly rotated and shifted on binding to dT(6-4)T, leading to the formation of an electrostatic interaction with the phosphate moiety of dT(6-4)T, which shows a remarkable induced fit...
February 1, 2019: Acta Crystallographica. Section F, Structural Biology Communications
Siyu Xia, Yao Huang, Jingchun Tang, Lan Wang
In this work, biochar (BC), activated carbon (AC), and graphene oxide (GO) were thiol-functionalized using 3-mercaptopropyltrimethoxysilane (3-MPTS) (named as BCS, ACS, and GOS, respectively). BCS, ACS, and GOS were synthesized mainly via the interaction between hydrolyzed 3-MPTS and surface oxygen-containing functional groups (e.g., -OH, O-C=O, and C=O) and π-π interaction. The materials before and after modification were characterized and tested for mercury removal, including sorption kinetics and isotherms, the effects of adsorbent dosage, initial pH, and ionic strength...
February 1, 2019: Environmental Science and Pollution Research International
Yue Jia, Lei Yang, Ruiqing Feng, Hongmin Ma, Dawei Fan, Tao Yan, Rui Feng, Bin Du, Qin Wei
In this work, an electrochemiluminescence (ECL) immunosensor was proposed utilizing MnCO3 nanospheres as a novel ECL luminophor and HWRGWVC (HC-7) heptapeptide as an efficient antibody capturer for site-directed immobilization with high affinity. MnCO3 nanospheres that prepared by homogeneous precipitation method exhibited high ECL efficiency, low toxicity, favorable biocompatibility and excellent stability. After the functionalization of poly dimethyl diallyl ammonium chloride (PDDA), the obtained MnCO3/PDDA could combine with gold nanoparticles (Au NPs) via electrostatic interaction (MnCO3/PDDA/Au)...
January 28, 2019: ACS Applied Materials & Interfaces
Luis Morales-Quintana, Cristian Carrasco-Orellana, Dina Beltrán, María Alejandra Moya-León, Raúl Herrera
Xyloglucan endotransglycosylase/hydrolases (XTH) may have endotransglycosylase (XET) and/or hydrolase (XEH) activities. Previous studies confirmed XET activity for PrXTH1 protein from radiata pine. XTHs could interact with many hemicellulose substrates, but the favorite substrate of PrXTH1 is still unknown. The prediction of union type and energy stability of the complexes formed between PrXTH1 and different substrates (XXXGXXXG, XXFGXXFG, XLFGXLFG and cellulose) were determined using bioinformatics tools. Molecular Docking, Molecular Dynamics, MM-GBSA and Electrostatic Potential Calculations were employed to predict the binding modes, free energies of interaction and the distribution of electrostatic charge...
January 19, 2019: Plant Physiology and Biochemistry: PPB
Jia-Hui Wang, Wei-Han Nie, Xiao-Xia Shao, Hao-Zheng Li, Meng-Jun Hu, Ya-Li Liu, Zeng-Guang Xu, Zhan-Yun Guo
Relaxin family peptides perform a variety of biological functions by activating four G protein-coupled receptors, namely relaxin family peptide receptor 1-4 (RXFP1-4). We recently disclosed electrostatic interactions of the homologous RXFP3 and RXFP4 with some agonists based on activation complementation. However, this activation assay-based approach cannot be applied to antagonists that do not activate receptors. Herein, we propose a general approach suitable for both agonists and antagonists based on our newly-developed NanoBiT-based binding assay...
January 23, 2019: Biochimica et biophysica acta. Biomembranes
Hao Jiang, Xiao-Yu Hu, Stefanie Mosel, Christoph Hirschhäuser, Shirley K Knauer, Carsten Schmuck
Recently, branched and dendrimeric cationic peptides have shown increasing transfection efficiency compared to linear peptides owing to their superior capacity for DNA condensation. Herein, we design and synthesize two analogously guanidinocarbonylpyrrole (GCP)-substituted branched cationic tripeptides, which provide extremely strong electrostatic attraction with plasmid DNA. Both ligands 1 and 2 can bind to plasmid DNA and form condensed complexes owing to the branched structure and high positive charges, as demonstrated by isothermal titration calorimetry (ITC), Zeta-potential and atomic-force microscopy (AFM)...
January 25, 2019: Chembiochem: a European Journal of Chemical Biology
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"