Biology subjects

Wade, N.

Publications and source records attributed to Wade, N..

5 recordsLinked to original sources

bioRxiv2026

Cryo-EM Structure of a Triazole alpha-Conotoxin GI Mimetic Bound to the Muscle-Type Nicotinic Acetylcholine Receptor

Disulfide-rich peptides possess exceptional potency and selectivity but are often limited by the instability and synthetic challenges associated with native disulfide bonds. Here, we report the design, synthesis, pharmacological evaluation, and structural characterisation of triazole-based peptidomimetics of the -GI conotoxin, a selective antagonist of the muscle-type nicotinic acetylcholine receptor (nAChR). A series of 1,4- and 1,5-disubstituted triazole analogues were prepared entirely on resin using CuAAC and RuAAC chemistry to replace the native Cys3/13 disulfide bridge. Functional evaluation against human muscle nAChRs revealed that 1,5-triazole analogues retained low-nanomolar potency, with the lead mimetic exhibiting activity comparable to native -GI. Cryo-electron microscopy of the lead compound bound to the muscle-type nAChR provided the first structure of a disulfide-isostere peptidomimetic in complex with a membrane receptor. The structure demonstrates that the 1,5-triazole reproduces the native peptide fold with high fidelity while contributing receptor-facing interactions not available to the native disulfide bridge. Molecular dynamics simulations further revealed conserved hydration networks and similar conformational sampling between the native peptide and lead mimetic. Together, these findings establish triazoles as effective disulfide surrogates and provide a structural framework for the rational design of stabilised conotoxin therapeutics.

biochemistry↗

bioRxiv2026

Structures of muscle-type nicotinic acetylcholine receptor with α-conotoxins reveal determinants of receptor-subtype specificity

-Conotoxins (-CTX) are disulfide-rich peptide antagonists with exceptional potency and subtype selectivity across nicotinic acetylcholine receptors (nAChRs), making them promising leads for therapeutic development. The molecular basis of their specificity has remained unresolved for decades, limiting rational drug design. Here, we present the first high-resolution cryo-EM structures of full-length muscle-type nAChR bound to three distinct -CTXs, revealing their precise binding modes at both acetylcholine binding sites. Our integrated approach, combining structural biology, pharmacological profiling, and computational hydration mapping, uncovers conserved pharmacophore features, water-mediated interactions, and subunit-specific determinants that govern potency and selectivity. These findings provide a long-sought molecular framework for -conotoxin recognition and inhibition, addressing a critical gap required to realise the full potential of conotoxins as lead compounds in drug discovery.

molecular biology↗

bioRxiv2025

Transcriptomic study of WSSV infection in Litopenaeus vannamei lymphoid organ via single nuclei RNA sequencing

BackgroundAquaculture is the fastest growing farmed food sector and is a key part of global food security. Crustacean aquaculture, while being one of the most profitable sectors, is threatened by pathogenic diseases such as white spot disease (WSD), which results in severe stock losses and threatens animal health and welfare. In this study, we used novel techniques to study the impact of white spot syndrome virus (WSSV), the causative agent of WSD, on Pacific whiteleg shrimp (Litopenaeus vannamei), and uncover additional information that may be used in creating WSSV-resistant shrimp stocks. ResultsWe successfully developed a novel nuclei isolation protocol optimized for shrimp tissues to prepare our samples for single nuclei RNA-sequencing following a pathogen challenge comprising of 32 adult whiteleg shrimp infected with WSSV either through their feed or by injection. We constructed the first penaeid shrimp lymphoid organ cell atlas to improve our understanding of the characteristics of this immune organ, constructed the UMAPs and identified marker genes that define distinct cell clusters to reveal the biological functions of different cell types within this organ. ConclusionBy comparing gene expression between the control and WSSV-infected samples we uncovered multiple genes of interest that that have the potential to be used as targets for CRISPR gene editing for WSSV-resistance in Pacific whiteleg shrimp. These genes have the potential to be valuable assets for future gene editing studies in commercially important penaeid shrimp species. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=90 SRC="FIGDIR/small/693182v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@1be071org.highwire.dtl.DTLVardef@2c3da6org.highwire.dtl.DTLVardef@835e67org.highwire.dtl.DTLVardef@aacff1_HPS_FORMAT_FIGEXP M_FIG C_FIG

genomics↗

bioRxiv2024

Inside Out: the physiology of Brucella Vegetative and Intracellular Growth.

Growth rate is a key prokaryotic trait that allows estimating fitness and understanding cell metabolism. While in some clades it has been well studied in model organisms, there is little data on slow-growing bacteria. In particular, there is a lack of quantitative studies on the species of the Brucella genus. This is an important microorganism since it is the causative agent of brucellosis, one of the most widespread bacterial zoonoses affecting several species of animals, including humans. Brucella species exhibit approximately 97% genomic similarity. Despite this, Brucella species show different host preferences, zoonotic risks, and pathogenicity. After more than one hundred years of research, numerous aspects of Brucella biology, such as in vivo and in vitro growth remain poorly characterized. In this work, we analyzed vegetative and intracellular growth of the classical Brucella species (B. abortus 2308, B. melitensis 16M. B. suis 1330, B. ovis, and B. canis). Strikingly, each species displayed particular growth parameters in culture. Doubling time (DT) spanned from 2.7 hs-1 in B. suis to 18h-1 for B. ovis. In the context of intracellular infection of J774A.1 phagocytic cells, DT was higher, but it widely varied across species, closely correlating to the growth observed in vitro. Overall, despite high similarity of the genomes, we found species-specific growth parameters in the intracellular cell cycle.

microbiology↗

bioRxiv2022

Dopamine transporter and synaptic vesicle sorting defects initiate auxilin-linked Parkinson's disease

Auxilin participates in the uncoating of clathrin-coated vesicles (CCVs), thereby facilitating synaptic vesicle (SV) regeneration at presynaptic sites. Auxilin (DNAJC6/PARK19) loss-of- function mutations cause early-onset Parkinsons disease (PD). Here, we utilized auxilin-knockout (KO) mice to elucidate the mechanisms through which auxilin deficiency and clathrin-uncoating deficits lead to PD. We demonstrate that auxilin KO mice display the cardinal features of PD, including progressive motor deficits, -synuclein pathology, nigral dopaminergic loss, and neuroinflammation. Through unbiased proteomic and neurochemical analyses, we demonstrate that dopamine homeostasis is disrupted in auxilin KO brains, including via slower dopamine reuptake kinetics in vivo, an effect associated with dopamine transporter misrouting into axonal membrane deformities in the dorsal striatum. We also show that elevated macroautophagy and defective SV protein sorting contribute to ineffective dopamine sequestration and homeostasis, ultimately leading to neurodegeneration. This study advances our knowledge of how presynaptic endocytosis deficits lead to dopaminergic vulnerability and pathogenesis of PD.

neuroscience↗