Crystallography

Itaconate is a key anti-inflammatory/antibacterial metabolite in pathogen-macrophage interactions that induces adaptive changes in Pseudomonas aeruginosa-exposed airways. However, the impact and mechanisms underlying itaconate metabolism remain unclear. Our study reveals that itaconate significantly upregulates the expression of pyoverdine in P. aeruginosa and enhances its tolerance to tobramycin. Notably, the enzymes responsible for efficient itaconate metabolism, PaIch and PaCcl, play crucial roles in both utilizing itaconate and clearing its toxic metabolic intermediates...

Two conserved second-sphere βArg (R) residues in nitrile hydratases (NHase), that form hydrogen bonds with the catalytically essential sulfenic and sulfinic acid ligands, were mutated to Lys and Ala residues in the Co-type NHase from Pseudonocardia thermophila JCM 3095 (PtNHase) and the Fe-type NHase from Rhodococcus equi TG328-2 (ReNHase). Only five of the eight mutants (PtNHase βR52A, βR52K, βR157A, βR157K and ReNHase βR61A) were successfully expressed and purified. Apart from the PtNHase βR52A mutant that exhibited no detectable activity, the kcat values obtained for the PtNHase and ReNHase βR mutant enzymes were between 1...

Many protein expression systems are primarily utilised to produce a single, specific recombinant protein. In contrast, most biological processes such as virus assembly rely upon a complex of several interacting proteins rather than the activity of a sole protein. The high complexity of the baculovirus genome, coupled with a multiphase replication cycle incorporating distinct transcriptional steps, made it the ideal system to manipulate for high-level expression of a single, or co-expression of multiple, foreign proteins within a single cell...

Manganese catalysts that activate hydrogen peroxide carry out several different hydrocarbon oxidation reactions with high stereoselectivity. The commonly proposed mechanism for these reactions involves a key manganese(III)-hydroperoxo intermediate, which decays via O-O bond heterolysis to generate a Mn(V)-oxo species that institutes substrate oxidation. Due to the scarcity of characterized MnIII -hydroperoxo complexes, MnIII -alkylperoxo complexes are employed to understand factors that affect the mechanism of the O-O cleavage...

This paper explores and revisits in detail the formation and characterization of sugar-based aminonitriles, whose ultimate origin can be traced to the interaction of biomolecules with cyanide. Although the synthesis and spectroscopic data of 2-amino-aldononitriles were reported long ago, there are both contradictory and confusing results among the published data. We have now addressed this concern through an exhaustive structural elucidation of acylated 2-amino- and 2-alkyl(aryl)amino-2-deoxyaldonitriles using mass spectrometry and FT-IR, FT-Raman, and NMR spectroscopies...

To understand the biological relevance and mode of action of artificial protein ligands, crystal structures with their protein targets are essential. Here, we describe and investigate all known crystal structures that contain a so-called "molecular tweezer" or one of its derivatives with an attached natural ligand on the respective target protein. The aromatic ring system of these compounds is able to include lysine and arginine side chains, supported by one or two phosphate groups that are attached to the half-moon-shaped molecule...

Reactions of Co(OAc)2 ·4H2 O, N'N' -bis(3-pyridylmethyl)oxalamide ( L ) and 4,4'-sulfonyldibenzoic acid (H2 SDA) afforded four coordination polymers with the same mixed ligands, {[Co( L )(SDA)(H2 O)2 ]·H2 O·CH3 OH}n , 1 , {[Co( L )0.5 (SDA)]·2H2 O·0.5 L }n , 2 , {[Co( L )1.5 (SDA)(H2 O)]·H2 O}n , 3 , and {[Co2 ( L )1.5 (SDA)2 (H2 O)2 ]·4H2 O}n , 4 , which have been structurally characterized using single-crystal X-ray crystallography. Complexes 1 - 4 are 2D layers, revealing topologies of sql , 2,6L1, (4,4)Ia, and 6L12, respectively, and demonstrating that the metal-to-ligand ratio, solvent system, and reaction temperature are important in determining the structural diversity...

Research on titanium-oxo complexes (TOCs) is usually focused on their structure and photocatalytic properties. Findings from these investigations further sparked our interest in exploring their potential biological activities. In this study, we focused on the synthesis and structure of a compound with the general formula [Ti8 O2 (Oi Pr)20 (man)4 ] ( 1 ), which was isolated from the reaction mixture of titanium(IV) isopropoxide with mandelic acid (Hman) in a molar ratio of 4:1. The structure ( 1 ) was determined using single-crystal X-ray diffraction, while spectroscopic studies provided insights into its physicochemical properties...

It is well known that daidzein has various significant medicinal values and health benefits, such as anti-oxidant, anti-inflammatory, anti-cancer, anti-diabetic, cholesterol lowering, neuroprotective, cardioprotective and so on. To our disappointment, poor solubility, low permeability and inferior bioavailability seriously limit its clinical application and market development. To optimize the solubility, permeability and bioavailability of daidzein, the cocrystal of daidzein and piperazine was prepared through a scientific and reasonable design, which was thoroughly characterized by single-crystal X-ray diffraction, powder X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis...

The absolute configuration and stability of two thianthrene chiral sulfoxides has been determined by means of X-ray single-crystal structure determinations. The analyses and configurations allow verification that the diastereomeric sulfoxides are stable in solution and are not interconverting, which has been suggested in some studies of sulfoxides. The two thianthrene sulfoxides have slightly different R f values, which allowed their separation using flash chromatography on silica. The spots run back-to-back, which posed a challenge for their separation...

The (pentamethylcyclopentadienyl)chloridoiridium(III) complex bearing a κ P ,κ S -bonded Ph2 PCH2 CH2 SPh ligand ([Ir(η5 -C5 Me5 )Cl(Ph2 P(CH2 )2 SPh-κ P, κ S )]PF6 , ( 1 )] was synthesized and characterized. Multinuclear (1 H, 13 C and 31 P) NMR spectroscopy was employed for the determination of the structure. Moreover, SC-XRD confirmed the proposed structure belongs to the "piano stool" type. The Hirshfeld surface analysis outlined the most important intermolecular interactions in the structure...

The vacuolar sorting receptors (VSRs) are specific to plants and are responsible for sorting and transporting particular proteins from the trans-Golgi network to the vacuole. This process is critically important for various cellular functions, including storing nutrients during seed development. Despite many years of intense studies on VSRs, a complete relation between function and structure has not yet been revealed. Here, we present the crystal structure of the entire luminal region of glycosylated VSR1 from Arabidopsis thaliana (AtVSR1) for the first time...

E6AP dysfunction is associated with Angelman syndrome and Autism spectrum disorder. Additionally, the host E6AP is hijacked by the high-risk HPV E6 to aberrantly ubiquitinate the tumor suppressor p53, which is linked with development of multiple types of cancer, including most cervical cancers. Here we show that E6AP and the E6AP/E6 complex exist, respectively, as a monomer and a dimer of the E6AP/E6 protomer. The short α1-helix of E6AP transforms into a longer helical structure when in complex with E6...

Edible plant seeds provide a relatively inexpensive source of protein and make up a large part of nutrients for humans. Plant seeds accumulate storage proteins during seed development. Seed storage proteins act as a reserve of nutrition for seed germination and seedling growth. However, seed storage proteins may be allergenic, and the prevalence of food allergy has increased rapidly in recent years. The 11S globulins account for a significant number of known major food allergens. They are of interest to the public and the agricultural industry because of food safety concerns and the need for crop enhancement...

The low-temperature treatment of 1,1-dibromo-1a,9b-cyclopropa[ l ]phenanthrene with butyllithium appeared to produce dibenzonorcarynyliden(e/oid) which could be intercepted with phencyclone to produce a hindered spiropentane. The spiropentane readily rearranges, thermally and photochemically, into a triphenylene phenol derivative. The spiropentane and its rearrangement product were characterized by X-ray crystallography.

CONTEXT: The controlled slow evaporation process conducted at room temperature has produced a novel hybrid material denoted as (2-hydroxyethyl) trimethylammonium dihydrogen phosphate [2-HDETDHP] (C5 H14 NO+ , H2 PO4 - ), synthesized through the solution growth method. X-ray crystallography analysis reveals a triclinic structure with a filling rate of P and a Z value of 2. This hybrid material displays noteworthy absorption characteristics in the middle and far ultraviolet regions...

Poly-stoichiometry of hydrated phases is relatively uncommon for organic materials and extended libraries of such species adopting different aqua-to-substrate ratios are still rare. The kinetically controlled higher hydrates could be particularly interesting for their structural relationships, which presumably may imprint some features of the substrate/substrate and aqua/substrate bonding in solutions, and provide insights into the nucleation stage. Two metastable high hydrates are prepared by crash crystallization...

Three novel meroterpenoids, taladrimanins B-D ( 1 - 3 ), were isolated from the marine-derived fungus Talaromyces sp. M27416, alongside three biogenetically related compounds ( 4 - 6 ). We delineated taladrimanin B's ( 1 ) structure using HRESIMS and NMR, confirmed its configuration via quantum chemical NMR analysis and DP4+ methodology, and verified it through X-ray crystallography. ECD calculations determined the absolute configuration of compound 1 , while comparative NMR and ECD analyses elucidated the absolute configurations of 2 and 3 ...

Three pairs of enantiomers ( 1 - 3 )-the new 12 R -aloesol ( 1a ) and two new fatty acids ( 2 and 3 )-and one new natural product ( 4 ) together three known compounds ( 5 - 7 ) were isolated from a coral-reef-derived Streptomyces sp. SCSIO 66814. Their structures were determined through extensive spectroscopic analysis, chiral analysis, and single-crystal X-ray diffraction data. Compounds 2 and 3 were presumed to be intermediates for further generating homononactic acid ( 5 ) and nonactic acid, and the latter two molecules were able to act as precursors to form macrotetrolides with remarkable biological activity...

Four undescribed sesquiterpenoids, lemneolemnanes A-D ( 1 - 4 ), have been isolated from the marine soft coral Lemnalia sp. The absolute configurations of the stereogenic carbons of 1 - 4 were determined by single-crystal X-ray crystallographic analysis. Compounds 1 and 2 are epimers at C-3 and have an unusual skeleton with a formyl group on C-6. Compound 3 possesses an uncommonly rearranged carbon skeleton, while 4 has a 6/5/5 tricyclic system. Compound 1 showed significant anti-Alzheimer's disease (AD) activity in a humanized Caenorhabditis elegans AD pathological model...