I12-JEEP: Joint Engineering, Environmental and Processing
|
Ilaria
Quaratesi
,
Ioan
Călinescu
,
Petre
Chipurici
,
Elisa-Gabriela
Dumbravă
,
Andrei
Cucos
,
Mohamed Yassine
Zaki
,
Pellegrino
La Manna
,
Adrian
Bercea
,
Miruna Silvia
Stan
,
Stefan
Michalik
,
Chloe
Pearce
,
Marianne
Odlyha
,
Genoveva
Burca
,
Elena
Badea
Diamond Proposal Number(s):
[35634]
Open Access
Abstract: This study presents an ultrasound-assisted synthesis of β-cyclodextrin/hydroxyapatite composites to be used as green and safe auxiliaries in the tanning process. A combination of spectroscopic and non-spectroscopic techniques such as DLS (dynamic light scattering), ZP (zeta potential), XRD (X-ray diffraction), SEM (scanning electron microscopy) and ATR-FTIR (attenuated total reflectance-Fourier transform infrared spectroscopy) were used to thoroughly characterize the eight composites obtained by varying the ultrasound process parameters. While not cytotoxic, all composites had strong antibacterial action against Brevibacterium lines, Staphylococcus aureus, Escherichia coli, and Staphylococcus epidermis. All composites underwent lab-scale tanning tests, but only those exhibiting the most suitable set of tanning abilities underwent pilot-scale testing. The composites' interaction with the collagen matrix was assessed by micro-DSC (micro-differential scanning calorimetry), TG/DTG/DTA (thermal analysis), 1H unilateral NMR (proton nuclear magnetic resonance), ATR-FTIR, in-situ temperature synchrotron-based XRD and standard tests (UNI EN ISO 3380: 2015, UNI EN ISO 2589: 2016, UNI EN ISO 105- B02:2014). Thermal stability, dye penetration, thickness, colour fastness, surface appearance and microbiological protection were all improved for the leather treated with a small amount of composite added to the wet finish float. These findings demonstrate the benefits of β-cyclodextrin/hydroxyapatite composites as safe and sustainable tanning additives.
|
Apr 2025
|
|
I19-Small Molecule Single Crystal Diffraction
|
Diamond Proposal Number(s):
[30375]
Abstract: We present a combined experimental and density functional theory study that characterizes the charge and spin density in NiX2(3,5-lutidine)4 (X = Cl, Br and I). In this material, magnetic exchange interactions occur via Ni2+–halide⋯halide–Ni2+ pathways, forming one-dimensional chains. We find evidence for weak halide⋯halide covalency in the iodine system, which is greatly reduced when X = Br and is absent for X = Cl; this is consistent with the reported `switching-on' of magnetic exchange in the larger-halide cases. Our results are benchmarked against density functional theory calculations on [NiHF2(pyrazine)2]SbF6, in which the primary magnetic exchange is mediated by F–H–F bridging ligands. This comparison indicates that, despite the largely depleted charge density found at the centre of halide⋯halide bonds, these through-space interactions can support strong magnetic exchange gated by weak covalency and enhanced by significant electron density overlapping that of the transition metal centres.
|
Apr 2025
|
|
I03-Macromolecular Crystallography
|
Open Access
Abstract: Differential scanning fluorimetry screening of the Library of Pharmacologically Active Compounds (LOPAC) identified four hits for the PRYSPRY domain of the human E3 ligase tripartite motif-containing protein 21 (TRIM21). Isothermal titration calorimetry subsequently confirmed suramin as a binder with micromolar affinity. To further investigate the binding mechanism, mouse TRIM21 was used as a structural surrogate due to its improved protein stability and high sequence similarity to the human counterpart. A crystal structure of the complex refined at 1.3 Å resolution revealed a unique binding mode, providing new avenues for targeting TRIM21 and for the development of proteolysis-targeting chimeras (PROTACs).
|
Mar 2025
|
|
I15-Extreme Conditions
|
Diamond Proposal Number(s):
[30553]
Open Access
Abstract: BiFeO3-BaTiO3 (BF-BT) solid solutions have great potential as high-temperature piezoelectric transducers and energy storage dielectrics. However, the effects of donor doping in BF-BT on the local chemical heterogeneity and corresponding control of ferroelectric properties are not well investigated. In this study, it is shown that substitution of Nb5+ for Fe3+ at a concentration of only 0.1 at% in 0.75BF-0.25BT ceramics can induce pronounced core-shell microstructural features, which are not evident for pure BF-BT ceramics or those doped with 0.1 at% Nb5+ for Ti4+. The spatial distribution of Nb, confirmed by Nano-SIMS with exceptional resolution and sensitivity, reveals the role of Nb as an aliovalent solute that inhibits chemical homogenization, stabilizing the formation of Bi-, Fe-enriched core and Ba-, Ti-enriched shell regions at high temperatures, and reducing inter-diffusion during sintering. Electric field-induced domain switching and lattice strain measurements, obtained by in-situ high-energy synchrotron X-ray diffraction, revealed the effects of elastic constraint between the core and shell regions, which degraded the dielectric, ferroelectric, and piezoelectric properties. In contrast, substitution of 0.1 at% Nb on the Ti4+ site gave rise to more homogeneous materials and induced a softening effect with enhanced functional properties. This study provides an advanced investigation into the effects of trace amounts of donor dopant in BF-BT ceramics and offers valuable insights into optimizing doping strategy to control their microstructure and functional properties.
|
Mar 2025
|
|
I23-Long wavelength MX
|
Diamond Proposal Number(s):
[32794]
Open Access
Abstract: Voltage-dependent anion channel 1 (VDAC1) is a key protein in cellular metabolism and apoptosis. Here, we present a protocol to express and purify milligram amounts of recombinant VDAC1 in Escherichia coli. We detail steps for a fluorescence polarization-based high-throughput screening assay using NADH displacement, along with procedures for thermostability, fluorescence polarization, and X-ray crystallography. In this context, we demonstrate how 2-methyl-2,4-pentanediol (MPD), a crystallization reagent, interferes with VDAC1 small-molecule binding, hindering the detection of these ligands in the crystal.
|
Mar 2025
|
|
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
|
Virginie
Will
,
Lucile
Moynie
,
Elise
Si Ahmed Charrier
,
Audrey
Le Bas
,
Lauriane
Kuhn
,
Florian
Volck
,
Johana
Chicher
,
Hava
Aksoy
,
Morgan
Madec
,
Cyril
Antheaume
,
Gaëtan L. A.
Mislin
,
Isabelle J.
Schalk
Diamond Proposal Number(s):
[33133]
Abstract: Iron is essential for bacterial growth, and Pseudomonas aeruginosa synthesizes the siderophores pyochelin (PCH) and pyoverdine to acquire it. PCH contains a thiazolidine ring that aids in iron chelation but is prone to hydrolysis, leading to the formation of 2-(2-hydroxylphenyl)-thiazole-4-carbaldehyde (IQS). Using mass spectrometry, we demonstrated that PCH undergoes hydrolysis and oxidation in solution, resulting in the formation of aeruginoic acid (AA). This study used proteomic analyses and fluorescent reporters to show that AA, dihydroaeruginoic acid (DHA), and PCH induce the expression of femA, a gene encoding the ferri-mycobactin outer membrane transporter in P. aeruginosa. Notably, the induction by AA and DHA was observed only in strains unable to produce pyoverdine, suggesting their weaker iron-chelating ability compared to that of pyoverdine. 55Fe uptake assays demonstrated that both AA-Fe and DHA-Fe complexes are transported via FemA; however, no uptake was observed for PCH-Fe through this transporter. Structural studies revealed that FemA is able to bind AA2-Fe or DHA2-Fe complexes. Key interactions are conserved between FemA and these two complexes, with specificity primarily driven by one of the two siderophore molecules. Interestingly, although no iron uptake was noted for PCH through FemA, the transporter also binds PCH-Fe in a similar manner. These findings show that under moderate iron deficiency, when only PCH is produced by P. aeruginosa, degradation products AA and DHA enhance iron uptake by inducing femA expression and facilitating iron transport through FemA. This provides new insights into the pathogen’s strategies for iron homeostasis.
|
Mar 2025
|
|
I19-Small Molecule Single Crystal Diffraction
|
Diamond Proposal Number(s):
[21497]
Open Access
Abstract: Here, we report two (AgI3I)4L4 metal-organic cages that each contain a previously unobserved trisilver(I) iodide cluster at their vertices. Clusters containing fewer than 10 AgI ions are challenging to synthesize in an atomically precise manner. Previous work has demonstrated the potential of the approach of generating such clusters during the formation of higher-order metal-organic cage superstructures, but too few examples were known for design principles to be deciphered. Through analysis of the set of such cages reported herein and previously, we elaborate a set of design principles for their synthesis.
|
Mar 2025
|
|
I11-High Resolution Powder Diffraction
|
Diamond Proposal Number(s):
[25166]
Open Access
Abstract: We report two three-dimensional metal-organic frameworks constructed from Fe3+ and the ligand, 2,5-furandicarboxylate (FDC) that can be derived from biomass. One contains an unprecedented infinite-rod-shaped building unit, and the other is the first crystalline framework of FDC that contains solely iron in the metal nodes. The materials are formed as microcrystals and their structures determined using 3D-electron diffraction with the bulk confirmed by powder XRD. UOW-7, NaFe5O3(FDC)4(CH3COO)2 is a bimetallic structure with acetate as co-ligand, constructed from infinite chains of iron octahedra, wherein tetramers comprising edge-sharing pairs linked by corner sharing octahedra are crosslinked by FDC ligands. In contrast, UOW-8, Fe2O(FDC)2(H2O)2]·(H2O)4 contains a rare form of tetrameric building unit, cross-linked by FDC, and having Fe-bound water as well as occluded water. The materials crystallise under hydrothermal conditions and are water-stable coordination polymers with no measurable free pore space. The catalytic ability of UOW-7 and UOW-8 is, nevertheless, established in the reduction of 4-nitrophenol to 4-aminophenol by borohydride, where both act as recyclable, catalysts to give ~100% yield of the product without use of precious metals. UOW-8 is found to have the more favourable reaction kinetics, likely due to the presence of surface Lewis acidic Fe3+ centres that enhance substrate binding.
|
Mar 2025
|
|
I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
|
Alexandra
Males
,
Olga V.
Moroz
,
Elena
Blagova
,
Astrid
Munch
,
Gustav H.
Hansen
,
Annette H.
Johansen
,
Lars H.
Østergaard
,
Dorotea R.
Segura
,
Alexander
Eddenden
,
Anne V.
Due
,
Martin
Gudmand
,
Jesper
Salomon
,
Sebastian R.
Sørensen
,
Joao Paulo L.
Franco Cairo
,
Mark
Nitz
,
Roland A.
Pache
,
Rebecca M.
Vejborg
,
Sandeep
Bhosale
,
David J.
Vocadlo
,
Gideon J.
Davies
,
Keith S.
Wilson
Diamond Proposal Number(s):
[13587]
Open Access
Abstract: Microorganisms are known to secrete copious amounts of extracellular polymeric substances (EPS) that form complex matrices around the cells to shield them against external stresses, to maintain structural integrity and to influence their environment. Many microorganisms also secrete enzymes that are capable of remodelling or degrading EPS in response to various environmental cues. One key enzyme class is the poly-β-1,6-linked N-acetyl-D-glucosamine (PNAG)-degrading glycoside hydrolases, of which the canonical member is dispersin B (DspB) from CAZy family GH20. We sought to test the hypothesis that PNAG-degrading enzymes would be present across family GH20, resulting in expansion of the sequence and structural space and thus the availability of PNAGases. Phylogenetic analysis revealed that several microorganisms contain potential DspB-like enzymes. Six of these were expressed and characterized, and four crystal structures were determined (two of which were in complex with the established GH20 inhibitor 6-acetamido-6-deoxy-castanospermine and one with a bespoke disaccharide β-1,6-linked thiazoline inhibitor). One enzyme expressed rather poorly, which restricted crystal screening and did not allow activity measurements. Using synthetic PNAG oligomers and MALDI-TOF analysis, two of the five enzymes tested showed preferential endo hydrolytic activity. Their sequences, having only 26% identity to the pioneer enzyme DspB, highlight the considerable array of previously unconsidered dispersins in nature, greatly expanding the range of potential dispersin backbones available for societal application and engineering.
|
Mar 2025
|
|
I04-Macromolecular Crystallography
|
Bine
Simonsen
,
Henriette
Rübsam
,
Marie Vogel
Kolte
,
Maria Meisner
Larsen
,
Christina
Krönauer
,
Kira
Gysel
,
Mette
Laursen
,
Feng
Feng
,
Gülendam
Kaya
,
Giles E. D.
Oldroyd
,
Jens
Stougaard
,
Sébastien
Fort
,
Simona
Radutoiu
,
Kasper Røjkjær
Andersen
Diamond Proposal Number(s):
[13062]
Open Access
Abstract: In this study, we investigate how the pseudokinase domain of the Medicago LYR4 LysM receptor kinase mediates downstream signaling in immunity. We determine the crystal structure of the LYR4 intracellular domain with an ATP-analog bound in a noncanonical manner and show that it is catalytically active despite its lack of canonical kinase features. However, in planta experiments demonstrate that the phosphorylation ability is not necessary for the function of LYR4 in chitin-triggered ROS production, but that the presence of its intracellular domain is indispensable. Thus, in chitin-triggered immunity the LYR4 intracellular domain serves as a signaling scaffold independent of its catalytic activity.
|
Mar 2025
|
|
