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Conversion of albumin into a BODIPY-like photosensitizer by a flick reaction, tumor accumulation and photodynamic therapy.

The accumulation of photosensitizers (PSs) in lesion sites but not in other organs is an important challenge for efficient image guiding in … cies under light irradiation. The crystal structure of the albumin PS was fully elucidated by X-ray crystallography; thus, further tuning of the structure will lead to novel physicochemical properties of the albumin PS, suggesting its potential in biological and clinical applications.

Modulation of the Cytotoxic Properties of Pd(II) Complexes Based on Functionalized Carboxamides Featuring Labile Phosphoryl Coordination Sites.

Platinum-based drugs are commonly recognized as a keystone in modern cancer chemotherapy. However, intrinsic and acquired resistance as well … were selectively synthesized and fully characterized using IR and NMR spectroscopy as well as X-ray crystallography. The preliminary evaluation of the anticancer potential of the resulting palladocycles revealed a strong dependence of their cytotoxic properties on the binding mode of the deprotonated amide ligands and demonstrated certain advantages of the pincer …

The Covalent Linking of Organophosphorus Heterocycles to Date Palm Wood-Derived Lignin: Hunting for New Materials with Flame-Retardant Potential.

Environmentally acceptable and renewably sourced flame retardants are in demand. Recent studies have shown that the incorporation of the bio … improved char-forming activity compared to the controls. 31P and HSQC NMR and small-molecule X-ray crystallography were used to analyse the prepared compounds and lignins.

Synthesis, Crystal Structure, Theoretical Calculations, Antibacterial Activity, Electrochemical Behavior, and Molecular Docking of Ni(II) and Cu(II) Complexes with Pyridoxal-Semicarbazone.

New Ni (II) and Cu (II) complexes with pyridoxal-semicarbazone were synthesized and their structures were solved by X-ray crystallography. This analysis showed the bis-ligand octahedral structure of [Ni(PLSC-H)2]·H2O and the dimer octahedral structure of [Cu(PLSC)(SO4)(H2O)]2·2H2O. Hirshfeld surface analysis was employed to determine the most important intermolecular interactions in the crystallographic structures. The structures of both complexes were further examined using density functional theory and natural bond orbital analysis. The photocatalytic decomposition of methylene blue in the p…

Structure-based design of a novel inhibitor of the ZIKA virus NS2B/NS3 protease.

Zika virus (ZIKV) has been a serious public health problem, and there is no vaccine or drug approved for the prevention or treatment of ZIKV yet. The ZIKV NS2B/NS3 protease plays an important role in processing the virus precursor polyprotein and is thus a promising target for antiviral drugs development. In order to discover novel inhibitors of this protease, we carried out a fragment-based hit screening and characterized protein-inhibitor interactions using the X-ray crystallography together with isothermal titration calorimetry. We reported two high-resolution crystal structures of the prot…

Structural characterization of Linum usitatissimum hydroxynitrile lyase: A new cyanohydrin decomposition mechanism involving a cyano-zinc complex.

Hydroxynitrile lyase from Linum usitatissimum (LuHNL) is an enzyme involved in the catabolism of cyanogenic glycosides to release hydrogen cyanide upon tissue damage. This enzyme strictly conserves the substrate- and NAD(H)-binding domains of Zn2+-containing alcohol dehydrogenase (ADH); however, there is no evidence suggesting that LuHNL possesses ADH activity. Herein, we determined the ligand-free 3D structure of LuHNL and its complex with acetone cyanohydrin and (R)-2-butanone cyanohydrin using X-ray crystallography. These structures reveal that an A-form NAD+ is tightly but not covalently b…

Structural and biochemical characterization of Leptospira interrogans Lsa45 reveals a penicillin-binding protein with esterase activity.

Leptospirosis is a bacterial disease that affects humans and animals and is caused by Leptospira. The recommended treatment for leptospirosis is antibiotic therapy, which should be given early in the course of the disease. Despite the use of these antibiotics, their role during the course of the disease is still not completely clear because of the lack of effective clinical trials, particularly for severe cases of the disease. Here, we present the characterization of L. interrogans Lsa45 protein by gel filtration, protein crystallography, SAXS, fluorescence and enzymatic assays. The oligomeric…

Morphology engineering of type-II heterojunction nanoarrays for improved sonophotocatalytic capability.

Sonophotocatalysis is one of the most significant outcomes of the exploration of the interaction between piezoelectric field and charge carr … ulcanization. Afterward, the ZnO/ZnS nanorods are etched to ZnO/ZnS nanotubes without affecting the crystallography and distribution of the ZnS nanoparticle shell, further improving the capability to 63.3%. The improvement can be ascribed to the coupling effect of the enhanced piezoelectric field and the reduced migration distance, which suppresses the recombinat …

Целенаправленные кавалентные ингибиторы Аллостерически деактивируют Вирус DEDDh Lassa Fever NP Exonuc арендован на альтернативных дистальных объектах.

Для использования целевых ковалентных ингибиторов (КНТ) в качестве противораковых и противовирусных препаратов мы установили, что составы модели PCMPS (p-хлормеркурифенил сульфат) и PCMB (p-хлорmercuribensoat) являются ингибиторами семейства DCDDh экзонуковых абонентов. Основополагающий механизм анализируется с помощью рентгеновской кристаллографии, анализа активности/нуклеиновой кислоты, имеющих обязательную силу, и моделирования молекулярной динамики (MD) в целом. Первая сложенная ТКИ структура фермента DEDDH, вируса лихорадки Ласса NP exonuc арендован (NPexo), преисполнена решимости разъясн

Совпадение в аннотации оригинала
For using targeted covalent inhibitors (TCIs) as anticancer and antiviral drugs, we establish that the model compounds PCMPS (p-chloromercuriphenyl sulfate) and PCMB (p-chloromercuribenzoate) are inhibitors of the DEDDh family of exonucleases. The underlying mechanism is analyzed by X-ray crystallography, activity/nucleic acid-binding assays, and all-atom mo…

Phosphite binding by the HtxB periplasmic binding protein depends on the protonation state of the ligand.

Phosphorus acquisition is critical for life. In low phosphate conditions, some species of bacteria have evolved mechanisms to import reduced … of genetically modified organisms by phosphite-dependent growth. Here we use a combination of X-ray crystallography, NMR and Microscale Thermophoresis to show that phosphite binding to HtxB depends on the protonation state of the ligand, suggesting that pH may effect the efficiency of phosphite uptake by HtxB in biotechnology applications.

An Unusual Dimeric Inhibitor of Acetylcholinesterase: Cooperative Binding of Crystal Violet.

Acetylcholinesterase (AChE) is an essential enzyme that terminates cholinergic transmission by a rapid hydrolysis of the neurotransmitter acetylcholine. AChE is an important target for treatment of various cholinergic deficiencies, including Alzheimer's disease and myasthenia gravis. In a previous high throughput screening campaign, we identified the dye crystal violet (CV) as an inhibitor of AChE. Herein, we show that CV displays a significant cooperativity for binding to AChE, and the molecular basis for this observation has been investigated by X-ray crystallography. Two monomers of CV bind…

Isostructurality among solvates of cabazitaxel: X-ray structures and new solvates preparation.

Cabazitaxel is an anticancer drug and its marketed product (form A) is acetone solvate (1:1) (Didier E, Perrin MA. 2005. Patent WO2005/02846 … ). All the seven solvates involved in this work were proven to be isostructural by methods of X-ray crystallography and contain the same amount of solvents by thermogravimetric analysis. The single-crystal structures of solvate C-E and the solvates prepared by solvent-replacement method have been reported for the first time.

Novel, mercury-free synthetic pathway for trifluoromethylthio-substituted metallocenes.

A novel synthetic pathway for trifluoromethylthioferrocene (3), which does not involve the use of toxic mercury(II)-based reagents, is descr … (19)F NMR spectroscopy, mass spectrometry, cyclic voltammetry, elemental analysis, as well by X-ray crystallography for 1, 4, 4b, 5, 6, and 7. 1-7 were further tested for their toxic activity on cervical cancer (HeLa) and noncancerous (MRC-5) cell lines. All organometallic compounds were found either to be nontoxic or to have a moderate toxicity toward the cell l …

Characterization of powdered fish heads for bone graft biomaterial applications.

OBJECTIVE: The aim of this study was to define the chemical composition, morphology and crystallography of powdered fish heads of the species Argyrosomus regius for bone graft biomaterial applications. METHODS: Two sizes of powder were prepared by different grinding methods; Powder A (coarse, d50=68.5 µm) and Powder B (fine, d50=19.1 µm). Samples were analyzed using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), thermogravimetry (TG), and energy dispersive X-ray spectroscopy (EDS). RESULTS: The powder was mainly composed of aragonite (CaCO3) and calcit…

A chromium(III)-superoxo complex in oxygen atom transfer reactions as a chemical model of cysteine dioxygenase.

Metal-superoxo species are believed to play key roles in oxygenation reactions by metalloenzymes. One example is cysteine dioxygenase (CDO) … )](+), formed in the OAT reactions by the chromium(III)-superoxo complex, is characterized by X-ray crystallography and various spectroscopic methods. The present results support the proposed oxidant and mechanism in CDO, such as an iron(III)-superoxo species is an active oxidant that attacks the sulfur atom of the cysteine ligand by the terminal oxygen atom of t …

Molecular motions as a drug target: mechanistic simulations of anthrax toxin edema factor function led to the discovery of novel allosteric inhibitors.

Edema Factor (EF) is a component of Bacillus anthracis toxin essential for virulence. Its adenylyl cyclase activity is induced by complexation with the ubiquitous eukaryotic cellular protein, calmodulin (CaM). EF and its complexes with CaM, nucleotides and/or ions, have been extensively characterized by X-ray crystallography. Those structural data allowed molecular simulations analysis of various aspects of EF action mechanism, including the delineation of EF and CaM domains through their association energetics, the impact of calcium binding on CaM, and the role of catalytic site ions. Further…

Evidence that histidine protonation of receptor-bound anthrax protective antigen is a trigger for pore formation.

The protective antigen (PA) component of the anthrax toxin forms pores within the low pH environment of host endosomes through mechanisms th … the host cellular receptor, an inability to undergo low pH-induced pore formation. Combining X-ray crystallography with hydrogen-deuterium (H-D) exchange mass spectrometry, our studies lead to a model in which hydrogen bonds to the histidine ring are strengthened by receptor binding. The combination of both fluorination and receptor binding is sufficient to bloc …

The crystal structure of the signature domain of cartilage oligomeric matrix protein: implications for collagen, glycosaminoglycan and integrin binding.

Cartilage oligomeric matrix protein (COMP), or thrombospondin-5 (TSP-5), is a secreted glycoprotein that is important for growth plate organization and function. Mutations in COMP cause two skeletal dysplasias, pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (EDM1). In this study, we determined the structure of a recombinant protein that contains the last epidermal growth factor repeat, the type 3 repeats and the C-terminal domain (CTD) of COMP to 3.15-A resolution limit by X-ray crystallography. The CTD is a beta-sandwich that is composed of 15 antiparallel beta-strands, and th…

Ionic recognition by 7-nitro-1,3,5-triaza adamantane: first thermodynamic study.

A thermodynamic study involving 7-nitro-1,3,5-triaza adamantane, 1, and its interaction with metal cations in nonaqueous media is first repo … to 1 led to the precipitation of the silver-1 complex which was isolated and characterized by X-ray crystallography. At variance with conductance measurements in solution, in the solid state the X-ray structure shows a 1:1 stoichiometry in the Hg(II) complex. The thermodynamics of complexation of 1 and these cations provide a quantitative assessment of the select …

[Thyroid hormones and lipid metabolism].

Thyroid hormone (T3) and its receptor (TR) have the diverse effects on the lipid metabolism and hypothyroidism causes hypercholesterolaemia characterized by increased levels of low-density ripoproteins (LDL). There are multiple TR isoforms such as TRalpha1, TRbeta1 and TRbeta2, of which expressions are known to be tissue-specific. For example, TRbeta1 is the major TR in the liver while T3 action is mediated via TRalpha1 in the heart. The X-ray crystallography of the ligand-binding domain of TRs enabled the development of TRbeta isoform specific T3 analogues including GC1. Without tachycardia, …