Arwen Irene Ingrid Tyler

Despite extensive research linking oat β-glucan (OBG) to improvements in cardiometabolic health, little is known about how OBG influences the structure and surface behavior of oat protein. To this end, enzymatic hydrolysis of an oat protein-β-glucan coextract (OPBG) from defatted oat flour was performed. The effect of OBG cleavage was characterized using asymmetric flow field-flow fractionation with ultraviolet–visible (UV–vis) and in situ fluorescence detection, allowing for deconvolution of protein and OBG signals. Partial OBG cleavage increased oat protein dispersibility and accelerated adsorption to the air–water interface, albeit partly driven by thermal treatment during enzymatic hydrolysis. Although full cleavage resulted in protein aggregation, all OPBG samples offered decreased air–water surface tension and faster solid surface-water adsorption kinetics compared to oat protein isolate (OPI). Novel findings highlight that oat protein surface behavior can be adjusted by omitting isoelectric precipitation, while retaining inherent OBG in the system to ultimately reduce protein–protein hydrophobic aggregation.

Enterohaemorrhagic Escherichia coli causes sporadic, and sometimes large-scale, food poisoning outbreaks, for which antibiotic treatment in humans is contraindicated. As an alternative form of therapy, previous studies developed the family of salicylidene acylhydrazide (SA) anti-virulence compounds. One target of the SA compounds is AdhE, an enzyme that converts acetyl-CoA to ethanol and vice versa. AdhE oligomerizes, forming helicoidal filaments, heterogeneous in length, called spirosomes. We show it is possible to only partially fractionate AdhE spirosomes because in vitro they oligomerize in the absence of stimuli, and that spirosome formation is necessary to regulate the direction of AdhE enzymatic reactions. We also show that the SA compound ME0054 binds and perturbs AdhE spirosomes, enhancing the conversion of ethanol to acetyl-CoA. This mechanistic understanding of how ME0054 impacts AdhE function will help in the development of SA compounds as novel anti-virulence inhibitors.

Small-angle X-ray and neutron scattering (SAXS and SANS) are versatile techniques for studying the structure of various materials and particles, enabling investigations of structures from a few to hundreds of nanometres. However, interpreting SAXS or SANS data can be challenging, hence the need for effective training. Here, we present the website SAStutorials.org, which offers tutorials on small-angle scattering (SAS) data analysis. The website serves as a learning platform that supports active learning both in the classroom and through self-study. The tutorials cover basic concepts, advanced modelling and theoretical aspects of SAS. Each tutorial follows a structure based on the principle of SOLO taxonomy, guiding learners from minimal or no knowledge in a given area to the ability to tackle real-world problems. SAStutorials.org has been developed as a community tool, providing tutorials that encompass a broad range of data analysis types, leveraging various programs and investigating different materials. Moreover, the website and all its data are open source, encouraging contributions from the community.

Protein force liability leads to dynamic change in building block shape, i.e. unfolding or changes in folded shape, resulting in a three-phase assembly process.

Lipid nanoparticles have important applications as biomedical delivery platforms and broader engineering biology applications in artificial cell technologies. These emerging technologies often require changes in the shape and topology of biological or biomimetic membranes. Here we show that topologically‐active lyotropic liquid crystal nanoparticles (LCNPs) can trigger such transformations in the membranes of giant unilamellar vesicles (GUVs). Monoolein (MO) LCNPs, cubosomes with an internal nanostructure of space group incorporate into 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) GUVs creating excess membrane area with stored curvature stress. Using time‐resolved fluorescence confocal and lattice light sheet microscopy, we observe and characterise various life‐like dynamic events in these GUVs, including growth, division, tubulation, membrane budding and fusion. Our results shed new light on the interactions of LCNPs with bilayer lipid membranes, providing insights relevant to how these nanoparticles might interact with cellular membranes during drug delivery and highlighting their potential as minimal triggers of topological transitions in artificial cells.

Lipid nanoparticles have important applications as biomedical delivery platforms and broader engineering biology applications in artificial cell technologies. These emerging technologies often require changes in the shape and topology of biological or biomimetic membranes. Here we show that topologically‐active lyotropic liquid crystal nanoparticles (LCNPs) can trigger such transformations in the membranes of giant unilamellar vesicles (GUVs). Monoolein (MO) LCNPs, cubosomes with an internal nanostructure of space group incorporate into 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) GUVs creating excess membrane area with stored curvature stress. Using time‐resolved fluorescence confocal and lattice light sheet microscopy, we observe and characterise various life‐like dynamic events in these GUVs, including growth, division, tubulation, membrane budding and fusion. Our results shed new light on the interactions of LCNPs with bilayer lipid membranes, providing insights relevant to how these nanoparticles might interact with cellular membranes during drug delivery and highlighting their potential as minimal triggers of topological transitions in artificial cells.

Designing plant protein-based aqueous lubricants can be of great potential to achieve sustainability objectives by capitalising on inherent functional groups without using synthetic chemicals; however, such a concept remains in its infancy. Here, we engineer a class of self-assembled sustainable materials by using plant-based protofilaments and their assembly within a biopolymeric hydrogel giving rise to a distinct patchy architecture. By leveraging physical interactions, this material offers superlubricity with friction coefficients of 0.004-to-0.00007 achieved under moderate-to-high (10²-to-10³ kPa) contact pressures. Multiscale experimental measurements combined with molecular dynamics simulations reveal an intriguing synergistic mechanism behind such ultra-low friction - where the uncoated areas of the protofilaments glue to the surface by hydrophobic interactions, whilst the hydrogel offers the hydration lubrication. The current approach establishes a robust platform towards unlocking an untapped potential of using plant protein-based building blocks across diverse applications where achieving superlubricity and environmental sustainability are key performance indicators.

Antibiotics are contraindicated for the treatment of infection enterohemorrhagic Escherichia coli (EHEC), a human pathogen that causes diarrhea or hemorrhagic colitis in humans which can progress to hemolytic uremic syndrome (HUS). As an alternative to the use of antibiotics, previous studies developed the salicylidene acylhydrazides (SA), a family of anti-virulence compounds capable of blocking expression of the type three secretion system (T3SS), thereby reducing bacterial infections. Here we validate AdhE as the anti-virulence protein target of the SA compound ME0054. AdhE is a bidirectional enzyme able to catalyse the conversion of acetyl-CoA to ethanol and vice versa . AdhE oligomerises forming helicoidal filaments heterogeneous in length called spirosomes. In this work, we show that it is possible to partially fractionate AdhE spirosomes using size exclusion chromatography (SEC) and to characterise the spirosome oligomers present in each fraction with biophysical techniques such as small angle X-ray scattering (SAXS) and sedimentation velocity analytical ultracentrifugation (SV-AUC). Also, we observe that short spirosomes are more efficient in the reverse reaction whereas the spirosome length has no impact on the forward reaction. Therefore, for first time, we reveal that AdhE spirosome formation is necessary to regulate the direction of its enzymatic reactions. In addition, we show that ME0054 disrupts AdhE spirosomes, thereby enhancing the conversion of ethanol to acetyl-CoA. Importantly, SV-AUC data show that ME0054 binds to the AdhE filaments. Finally, time-resolved (TR) SAXS allowed us to follow the kinetics of spirosome disruption produced by ME0054, confirming its effectiveness at biologically relevant temperatures and timescales. SIGNIFICANCE STATEMENT: There is an urgent need to develop alternative strategies to combat bacterial infections. Salicylidene acylhydrazides (SA) are able to reduce expression of the bacterial type three secretion system (T3SS), used by many pathogens to manipulate host eukaryotic cells, including our pathogen of interest: enterohaemorrhagic E. coli (EHEC). The mechanism underpinning these compounds is a mystery. Here we show how the SA compound ME0054, by disrupting AdhE spirosomes, enhances metabolic conversion of ethanol to acetyl-CoA. This finding is consistent with the phenotype observed in an EHEC AdhE mutant: alterations in acetate levels and changes in T3SS expression. Our work establishes a crucial mechanistic link between the binding of the SA compound to a key target protein and changes in bacterial metabolism.

Structural and dynamical behaviour of the inverse hexagonal phase illustrated by an electron density map and model, displaying regions of compression (thermal disorder: small arrows) and decompression (disorder of 2 ^nd kind: big arrows).