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Structure and Pharmacologic Modulation of Inhibitory Glycine Receptors.

Glycine receptors (GlyR) are inhibitory Cys-loop ion channels that contribute to the control of excitability along the central nervous system (CNS). GlyR are found in the spinal cord and brain stem, and more recently they were reported in higher regions of the CNS such as the hippocampus and nucleus accumbens. GlyR are involved in motor coordination, respiratory rhythms, pain transmission, and sensory processing, and they are targets for relevant physiologic and pharmacologic modulators. Several studies with protein crystallography and cryoelectron microscopy have shed light on the residues an…

A General Method for Targeted Quantitative Cross-Linking Mass Spectrometry.

Chemical cross-linking mass spectrometry (XL-MS) provides protein structural information by identifying covalently linked proximal amino acid residues on protein surfaces. The information gained by this technique is complementary to other structural biology methods such as x-ray crystallography, NMR and cryo-electron microscopy[1]. The extension of traditional quantitative proteomics methods with chemical cross-linking can provide information on the structural dynamics of protein structures and protein complexes. The identification and quantitation of cross-linked peptides remains challenging …

Counterion influence on the N-I-N halogen bond.

A detailed investigation of the influence of counterions on the [N-I-N]+ halogen bond in solution, in the solid state and in silico is prese … igh preference for the symmetric geometry was found also in the solid state by single crystal X-ray crystallography. Molecular systems encompassing weakly coordinating counterions behave similarly to the corresponding silver(i) centered coordination complexes. In contrast, systems possessing moderately or strongly coordinating anions show a distinctly different b …

Inter-domain communication of human cystathionine β-synthase: structural basis of S-adenosyl-L-methionine activation.

Cystathionine β-synthase (CBS) is a key enzyme in sulfur metabolism, and its inherited deficiency causes homocystinuria. Mammalian CBS is modulated by the binding of S-adenosyl-l-methionine (AdoMet) to its regulatory domain, which activates its catalytic domain. To investigate the underlying mechanism, we performed x-ray crystallography, mutagenesis, and mass spectrometry (MS) on human CBS. The 1.7 Å structure of a AdoMet-bound CBS regulatory domain shows one AdoMet molecule per monomer, at the interface between two constituent modules (CBS-1, CBS-2). AdoMet binding is accompanied by a reorien…

Expression of human AChR extracellular domain mutants with improved characteristics.

The muscle nicotinic acetylcholine receptor (AChR) has a central role in neuromuscular transmission, and is the major target in the autoimmu … fracting at ~12 Å. Further optimization is underway to obtain crystals suitable for high resolution crystallography. The proteins described herein are useful tools in structural studies of the human muscle AChR and can be used in applications requiring high yields such as therapeutic adsorbents for MG autoantibodies.

Genotype-phenotype correlations in neurogenetics: Lesch-Nyhan disease as a model disorder.

Establishing meaningful relationships between genetic variations and clinical disease is a fundamental goal for all human genetic disorders. However, these genotype-phenotype correlations remain incompletely characterized and sometimes conflicting for many diseases. Lesch-Nyhan disease is an X-linked recessive disorder that is caused by a wide variety of mutations in the HPRT1 gene. The gene encodes hypoxanthine-guanine phosphoribosyl transferase, an enzyme involved in purine metabolism. The fine structure of enzyme has been established by crystallography studies, and its function can be measu…

Synthesis and characterisation of anionic and neutral gallium(I) N-heterocyclic carbene analogues.

A high yield synthesis of a new, extremely bulky anionic gallium(I) N-heterocyclic carbene analogue, [(DAB*)Ga:](-) (DAB* = {N(Ar*)C(H)}(2), … y-product from this synthesis, [Ga(5)I(4)((But)MesNacnac)(3)], was also isolated and shown by X-ray crystallography to be a rare example of a compound bearing a group 13 metal-metal bonded chain stabilised by β-diketiminate ligands. A preliminary analysis of the bonding in the compound was carried out using DFT calculations.

Флавивирусы и их антигенная структура.

Флавивирусы представляют собой важные трансмиссивые артхроподом патогены человека, включая желтую лихорадку (YF), денге (Den), японский энцефалит (JE), Западный Нил (WN) и трансмиссивные энцефалиты (TBE), которые могут расширить свои эндемические районы в результате глобальных климатических, экологических и социально-экономических изменений. Хотя эффективные вакцины против YF, JE и TBE широко применяются, разработка вакцины против денге на протяжении длительного времени затруднена из-за обеспокоенности иммунопатологическими последствиями вакцинации. В настоящее время продолжаются клинические и

Совпадение в аннотации оригинала
Flaviviruses comprise important arthropod-transmitted human pathogens, including yellow fever (YF), dengue (Den), Japanese encephalitis (JE) … etails of the flavivirus particle structure have become available through the combined use of X-ray crystallography and cryo-electron microscopy that led to novel and surprising insights into the antigenic structure of these viruses. Recent studies provided evidence for an important role of virus maturation as well as particle dynamics in virus neutralization by …

Fragment-based discovery of nonpeptidic BACE-1 inhibitors using tethering.

BACE-1 (beta-site amyloid precursor protein cleaving enzyme), a prominent target in Alzheimer's disease drug discovery efforts, was surveyed … ining fragments and then for stand-alone, noncovalent inhibition of wild-type (WT) BACE-1 activity. Crystallography confirmed that the inhibitors bound in exactly the same mode as the disulfide-conjugated fragments that were originally selected from the screen. The ABP ligands represent a new type of nonpeptidic BACE-1 inhibitor motif that has not been described …

Characterization of Co-C bonding in dichlorovinylcobaloxime complexes.

This study combines theory and experiment in an examination of Co-C bonding and reductive Co-C cleavage in cobalt dichlorovinyl complexes. It is motivated by the role of dichlorovinyl complexes as intermediates in the dechlorination of trichloroethylene by cobalamin and cobalamin model complexes. A series of seven cis-1,2-dichlorovinyl(L)cobaloxime complexes were prepared (L = m- and p-substituted pyridines; cobaloxime = bis(dimethylglyoximato)cobalt). The complexes were characterized using 1H NMR, 13C NMR, cyclic voltammetry, and X-ray crystallography. Examination of the metrical parameters o…

Structure-based optimization of a non-beta-lactam lead results in inhibitors that do not up-regulate beta-lactamase expression in cell culture.

Bacterial expression of beta-lactamases is the most widespread resistance mechanism to beta-lactam antibiotics, such as penicillins and ceph … ructures of AmpC in complex with compound 10 and an analogue, compound 11, were determined by X-ray crystallography to 1.97 and 1.96 A, respectively. Compound 10 was active in cell culture, reversing resistance to the third generation cephalosporin ceftazidime in bacterial pathogens expressing AmpC. In contrast to beta-lactam-based inhibitors clavulanate and cefo …

Structural basis for the voltage-gated Na+ channel selectivity of the scorpion alpha-like toxin BmK M1.

Scorpion alpha-like toxins are proteins that act on mammalian and insect voltage-gated Na+ channels. Therefore, these toxins constitute an e … ation on three cloned voltage-gated Na+ channels (Nav1.2, Nav1.5 and para), a CD analysis and X-ray crystallography. The results reveal two molecular sites, a couplet of residues (8-9) in the RT and a hydrophobic surface consisting of residues 57 and 59-61 in the CT, where the substitution with specific residues can redirect the alpha-like characteristics of BmK …

Towards selectively modulating mineralocorticoid receptor function: lessons from other systems.

Although there is clinical utility in blocking mineralocorticoid receptor (MR) action, the usefulness of available MR antagonists is limited … iven the similarities in structure and function. We have used traditional approaches aided by X-ray crystallography to obtain several classes of selective ligands that modulate thyroid receptor (TR) action. We describe the properties of these selective TR modulators here, and discuss the possibility that similar approaches to ligand design may yield MR interactin …

Active site analysis of the potential antimicrobial target aspartate semialdehyde dehydrogenase.

Aspartate-beta-semialdehyde dehydrogenase (ASADH) lies at the first branch point in the biosynthetic pathway through which bacteria, fungi, and the higher plants synthesize amino acids, including lysine and methionine and the cell wall component diaminopimelate from aspartate. Blocks in this biosynthetic pathway, which is absent in mammals, are lethal, and inhibitors of ASADH may therefore serve as useful antibacterial, fungicidal, or herbicidal agents. We have determined the structure of ASADH from Escherichia coli by crystallography in the presence of its coenzyme and a substrate analogue th…

Modular Platform for Recombinant Production of Highly Toxic Bacterial Proteins.

Bacterial protein toxins constitute a vast, largely untapped reservoir of potent bioactive molecules for antimicrobial discovery and biotech … tivity following denaturation and refolding, while refolded PT9 was structurally validated by X-ray crystallography, demonstrating recovery of functionally and structurally competent proteins. Together, these findings establish a modular strategy for recombinant production of highly toxic bacterial proteins and facilitate their biochemical and functional characte …

The Use of Synchrotron Radiation in the Medical Sciences.

Synchrotron radiation (SR) sources provide unparalleled brilliance, collimation, coherence, and tunability, enabling specialized techniques that are crucial for advancing medical research across diverse fields from radiation oncology to rational drug design. Certain SR methods, such as macromolecular crystallography, are highly developed and automated, and have been used for decades for both fundamental understanding of biomolecules as well as pharmaceutical design, while other methods, such as microbeam radiation therapy, represent relatively recent developments. Scattering and diffraction me…

Crystallographic fragment screening discovers novel micromolar active inhibitors and druggable hotspots of SARS-CoV-2 PLpro.

The COVID-19 pandemic has highlighted the need to develop broad-spectrum antiviral therapeutics targeting rapidly evolving coronaviruses. This research focuses on SARS-CoV-2 PLpro, a conserved viral protease that plays dual roles in viral polyprotein processing and host immune suppression. Using an integrated fragment-based drug discovery (FBDD) approach that combines high-throughput X-ray crystallography and biochemical assays, we systematically screened a diverse library of 800 fragment compounds. Structural characterization identified 129 validated binders occupying 12 distinct binding site…

Screening assay to monitor mono-ADP-ribosylhydrolase activity of viral macrodomains in cells.

Mono-ADP-ribosylation, a modification of both proteins and nucleic acids, is implicated in innate immunity. Intracellularly, this modificati … l antiviral drug targets. Efforts to develop macrodomain inhibitors include computational modeling, crystallography-based methods, and in vitro assays. However, tools to study macrodomain activity directly in cells remain rare. Here, we established a cell-based assay using PARP15 isoform 1, which we found forms nuclear foci dependent on its ADP-ribosyltransferase …

Oxime Functionalization of Naringin and Naringenin: Tuning Structural, Physicochemical, and Biological Profiling.

Oxime functionalization represents a promising strategy for modulating the physicochemical and biological properties of flavonoids, with the relationship to biological behavior remaining ill-defined. In this work, naringin and naringenin have been converted to their oximated derivatives through an optimized high-yield synthetic protocol. Both derivatives were characterized by elemental analysis, FT-IR, UV-Visible, NMR, ESI-MS, and, for the first time, X-ray crystallography. Spectroscopic analyses confirmed the transformation of the carbonyl group to oxime (C = N-OH) and revealed the presence o…

Rapid generation of Drosophila Schneider 2 (S2) cell lines and FACS-based isolation of high-yield soluble or membrane proteins.

Efficient production of milligram quantities of properly folded, functional eukaryotic proteins remains a significant challenge for structur … Protein functionality was confirmed through receptor-binding assays, SEC-MALS, and high-resolution crystallography for HLA, and ligand-binding assays for hCD81. Overall, this faster, scalable workflow enables rapid, high-yield production of structurally intact, functionally active soluble and membrane proteins from small culture volumes, establishing S2 cells as …