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Abstract: Objective: To determine the high-resolution structure of human Copper-Zinc superoxide dismutase (hSOD1), an antioxidant enzyme whose mutations cause amyotrophic lateral sclerosis (ALS), under near-physiological conditions. Because SOD1 is intrinsically dynamic, capturing its structure at ambient temperature is key to understanding how temperature modulates its conformational flexibility, ensemble and functional states relevant to both catalysis and disease. Materials and Methods: Recombinant hSOD1 was expressed in E. coli, purified by affinity and size-exclusion chromatography, and crystallized at ambient temperature. Serial synchrotron crystallography (SSX) data were collected at 293 K at the EMBL P14-2 Time-Resolved Experiments with Crystallography (T-REXX) beamline at PETRA III, and compared with a 100 K cryogenic at the Diamond Light Source beamline (I03). Both datasets were processed and refined using CCP4 suite and PHENIX packages. B-factor distributions, per-residue RMSD values, and conformational differences were analyzed to quantify temperature-dependent effects. Results: The ambient-temperature SOD1SSX structure was determined at 2.3 Å resolution (PDB ID:9XJ0 this work) and closely matched its 2.37 Å cryogenic counterpart (SOD1CRYO, PDB ID:9XJI this work), both obtained from identical crystallization conditions in the hexagonal P6₃ space group. Cryocooling caused a 3.8% contraction in unit-cell volume, consistent with lattice densification and a 5.2% reduction in molecular surface volume. Despite the overall similarities, the ambient-temperature model revealed localized conformational differences in solvent-exposed loop residues, particularly Ser25-Asn26, Leu67-Glu77, Ile99, and the Asp109-His110-Cys111 triad, and a distinct side-chain orientation of Asn53 was observed at the dimerization interface. While the β-barrel core remained rigid, these regions correspond to redox- and metal-responsive sites implicated in aggregation/fiber formation and putative drug binding. Conclusions: Temperature perturbs local dynamics in SOD1 structure without altering its native dimeric form. The ambient-temperature model reveals flexible, chemically accessible regions that act as druggable hotspots and coincide with ALS-linked mutation sites driving misfolding and aggregation. Considering temperature effects is crucial for structure-based drug design, ensuring candidate molecules engage physiologically relevant conformations. This structure lays the groundwork for future time-resolved crystallography of SOD1 folding and ligand interactions.

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Abstract: Photoemission electron microscopy (PEEM) offers a potential third modality for large-volume connectomics alongside transmission electron microscopy (TEM) and scanning electron microscopy (SEM). We image osmium stained, ultrathin brain sections on gold coated silicon at synaptic resolution using commercial PEEMs. At coarser resolution, we demonstrate that ultraviolet laser illumination enables gigavoxel-per-second acquisition rates without thermal damage. PEEM combines TEM-like parallel detection with SEM-compatible solid supports into a potentially scalable and cost-effective approach for large-volume connectomes.

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Abstract: The soluble epoxide hydrolase (sEH) has recently emerged as a promising target for the treatment of several pain-related conditions. Herein, we report the design and synthesis of a peripherally restricted sEH inhibitor with high potency and good Drug Metabolism and Pharmacokinetics (DMPK) properties. Molecular dynamics and X-ray crystallography helped reveal the binding of these inhibitors to sEH. The selected compound showed a robust analgesic effect in a dose-dependent manner in a murine model of chemotherapy-induced neuropathic pain (CINP). Moreover, the compound also prevented the development of paclitaxel-induced neuropathic pain. Overall, these results suggest that peripheral inhibition of sEH might constitute a novel therapy to prevent and treat CINP.

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Abstract: Since the first paper published by Susan Cole in 1990 detailing multidrug resistance mediated by ABCC1/MRP1, research into the C-subfamily of ATP-binding cassette transporters has continued to uncover a wide range of functionally divergent proteins. However, several orphan transporters remain in the C-subfamily, and the physiological function and substrates of ABCC5, ABCC11, and ABCC12 remain elusive. This review explores the emerging understanding of human ABCC5. Unlike other ABC transporters with well-defined drug export functions, ABCC5’s physiological roles remain only partially understood. While it is known for its involvement in multidrug resistance in cancers, recent studies suggest broader implications in development, metabolism, neurobiology, and male fertility. ABCC5 exports various endogenous substrates, including cyclic nucleotides (cAMP and cGMP), glutamate conjugates like NAAG, and possibly haem. Knockout models in mice, zebrafish, and sea urchins reveal ABCC5’s role in gut formation, brain function, eye development, and iron metabolism. In mice, its deletion results in lower adipose tissue mass, enhanced insulin sensitivity, and neurobehavioral changes resembling schizophrenia, highlighting its role in glutamatergic signalling and circadian regulation. Functionally, ABCC5 appears to impact adipocyte differentiation and GLP-1 release, implicating it in type 2 diabetes susceptibility in humans. Structural studies using human ABCC5 revealed a novel autoinhibitory mechanism involving a peptide segment (C46–S64) that blocks substrate binding, offering new potential for selective inhibitor development. However, this review emphasises caution in targeting ABCC5 for cancer therapy due to its underappreciated physiological function(s), particularly in the brain and male reproductive system. Understanding ABCC5’s substrate specificity, regulatory mechanisms, and functional redundancy with its paralog ABCC12 remains critical for successful therapeutic strategies in humans.

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Abstract: Mutations in the E3 ubiquitin ligase Parkin gene have been linked to early onset Parkinson’s disease. Besides many other roles, Parkin is involved in clearance of damaged mitochondria via mitophagy—a process of particular importance in dopaminergic neurons. Upon mitochondrial damage, Parkin accumulates at the outer mitochondrial membrane and is activated, leading to ubiquitination of many mitochondrial substrates and recruitment of mitophagy effectors. While the activation mechanisms of autoinhibited Parkin have been extensively studied, it remains unknown how Parkin recognizes its substrates for ubiquitination. Here, we characterize a conserved region in the flexible linker between the Ubl and RING0 domains of Parkin, which is indispensable for Parkin interaction with the mitochondrial GTPase Miro1. Our results may explain fast kinetics of Miro1 ubiquitination by Parkin in recombinant assays and provide a biochemical explanation for Miro1-dependent Parkin recruitment to the mitochondrial membrane observed in cells. Our findings are important for understanding mitochondrial homeostasis and may inspire new therapeutic avenues for Parkinson’s disease.