Dr S.E. Jackson

The COVID-19 pandemic has had an immense impact on the global population. Lockdown restrictions and school closures resulted in disruption to children’s learning and prolonged periods of social isolation from peers, throughout a crucial time in their development. By examining children’s lived experiences of lockdown and their transition back to school, this study aimed to understand how children have dealt with the challenges presented by the pandemic. In doing so, this may provide guidance for families and educators in their support of children in the future. In the aftermath of lockdown, face-to-face interviews with six children, aged 10–11 years, were conducted across three schools in the United Kingdom between October-November 2022. Semi-structured interviews provided a detailed account of participants’ experiences and were analysed thematically. Thematic analysis of the data identified five themes …

1Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA, 2Department of Pharmacology, University of California Davis, Davis, CA, USA, 3Department of Entomology and Nematology, University of California Davis, Davis, CA, USA, 4AnaBios, San Diego, CA, USA, 5AmbioPharm, North Augusta, GA, USA, 6Comprehensive Cancer Center, University of California Davis, Davis, CA, USA. The voltage-gated sodium NaV1. 7 channel plays a key role as a mediator of action potential propagation in C-fiber nociceptors and is an established molecular target for pain therapy. ProTx-II is a potent and moderately selective peptide toxin from tarantula venom that inhibits human NaV1. 7 activation. Here we used available structural and experimental data to guide Rosetta design of potent and selective ProTx-II-based peptide inhibitors of human NaV1. 7 channels. Functional testing of …

Childhood obesity continues to be a global concern and, in the UK, public health campaign's utilise behaviour science to encourage healthy eating and reduce sedentary behaviour for families. However, technology is now part of young people's everyday lives. Youtubers popularity mean that they can potentially act as effective peer influencers on healthier behaviours. This study provides a preliminary evaluation of four YouTube style vlogs produced by families for peers following a healthy eating intervention. Families were recruited to watch and review their learning and influence. The results show potential for using such approach as part of wider healthy eating campaign.

Knotted proteins are rare but important species, yet how their complex topologies affect their physical properties is not fully understood. Here we combine single molecule nanopore experiments and all-atom MD simulations to study the electric-field-driven unfolding during the translocation through a model pore of individual protein knots important for methylating tRNA. One of these knots shows an unusual behavior that resembles the behavior of electrons hopping between two potential surfaces: as the electric potential driving the translocation reaction is increased, the rate eventually plateaus or slows back down in the “Marcus inverted regime”. Our results shed light on the influence of topology in knotted proteins on their forced translocation through a pore connecting two electrostatic potential wells.

The caseinolytic protease complex ClpXP is an important house-keeping enzyme in prokaryotes charged with the removal and degradation of misfolded and aggregated proteins and performing regulatory proteolysis. Dysregulation of its function, particularly by inhibition or allosteric activation of the proteolytic core ClpP, has proven to be a promising strategy to reduce virulence and eradicate persistent bacterial infections. Here, we report a rational drug-design approach to identify macrocyclic peptides which increase proteolysis by ClpP. This work expands the understanding of ClpP dynamics and sheds light on the conformational control exerted by its binding partner, the chaperone ClpX, by means of a chemical approach. The identified macrocyclic peptide ligands may, in the future, serve as a starting point for the development of ClpP activators for antibacterial applications.

De novo protein design methods can create proteins with folds not yet seen in nature. These methods largely focus on optimizing the compatibility between the designed sequence and the intended conformation, without explicit consideration of protein folding pathways. Deeply knotted proteins, whose topologies may introduce substantial barriers to folding, thus represent an interesting test case for protein design. Here we report our attempts to design proteins with trefoil (31) and pentafoil (51) knotted topologies. We extended previously described algorithms for tandem repeat protein design in order to construct deeply knotted backbones and matching designed repeat sequences (N = 3 repeats for the trefoil and N = 5 for the pentafoil). We confirmed the intended conformation for the trefoil design by X ray crystallography, and we report here on this protein’s structure, stability, and folding behaviour. The …

The physical stability of peptide-based drugs is of great interest to the pharmaceutical industry. Glucagon-like peptide 1 (GLP-1) is a 31-amino acid peptide hormone, the analogs of which are frequently used in the treatment of type 2 diabetes. We investigated the physical stability of GLP-1 and its C-terminal amide derivative, GLP-1-Am, both of which aggregate into amyloid fibrils. While off-pathway oligomers have been proposed to explain the unusual aggregation kinetics observed previously for GLP-1 under specific conditions, these oligomers have not been studied in any detail. Such states are important as they may represent potential sources of cytotoxicity and immunogenicity. Here, we identified and isolated stable, low-molecular-weight oligomers of GLP-1 and GLP-1-Am, using size-exclusion chromatography. Under the conditions studied, isolated oligomers were shown to be resistant to fibrillation or …

In recent decades, studies have investigated associations between learning disorders such as Autism Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD), and the various types of internet addictions, ranging from general internet addiction (GIA) to specific internet addictions such as social media addiction (SMA) and internet gaming disorder (IGD). However, to date, no study has investigated such internet addictions among persons with dyslexia. The present study aimed to investigate whether differences exist between adults with dyslexia and controls in terms of GIA, SMA and IGD. A total of 141 adults with dyslexia and 150 controls (all UK based) were recruited. Controlling for age, gender, marital status, employment, and income levels, it was found that adults with dyslexia had higher levels of GIA and IGD compared to controls. However, these participants did not show any significant difference in terms of SMA. The results indicate that internet addictions may have a larger ambit for learning disorders beyond just ASD and ADHD and could be a hidden problem for these individuals.

Theory of mind has been shown to be important for listening comprehension for children at a range of ages. However, there is a lack of longitudinal evidence for a relationship between early theory of mind and later listening comprehension. The aim of this study was to examine whether preschool theory of mind has a longitudinal direct effect on later listening comprehension over and above the effects of concurrent theory of mind. A total of 147 children were tested on measures of theory of mind, working memory, vocabulary, and grammatical knowledge at Time 1 (mean age = 4;1 [years;months]) and Time 2 (mean age = 5;11). In addition, at Time 2 listening comprehension, comprehension monitoring, and inference making measures were taken. Data were fitted to concurrent and longitudinal models of listening comprehension. Concurrent findings at Time 2 showed theory of mind to have a direct effect on listening …

There is an increasing emphasis on the critical evaluation of interbatch purity and physical stability of therapeutic peptides. This is due to concerns over the impact that product- and process-related impurities may have on safety and efficacy of this class of drug. Aspartic acid isomerization to isoaspartic acid is a common isobaric impurity that can be very difficult to identify without first synthesizing isoAsp peptide standards for comparison by chromatography. As such, analytical tools that can determine if an Asp residue has isomerized, as well as the site of isomerization within the peptide sequence, are highly sought after. Ion mobility-mass spectrometry is a conformation-selective method that has developed rapidly in recent years particularly with the commercialization of traveling wave ion mobility instruments. This study employed a cyclic ion mobility (cIMS) mass spectrometry system to investigate the conformational …

Background Research with children shows that theory of mind predicts reading comprehension both concurrently and longitudinally, while research with adults shows increased print‐exposure relates to theory of mind understanding. However, until now whether reading and theory of mind have a mutually reinforcing relationship in which they promote one another in parallel has not been explored. Therefore, this study aims to explore further the relationship between theory of mind and reading by investigating reading comprehension, print‐exposure and theory of mind together. Method Theory of mind (Reading the Eyes in the Mind test), reading comprehension (subset of the York Adult Assessment Battery‐Revised) and print‐exposure (Authors Recognition Test) were measured in a sample of U.K. adults (N = 220). Results Findings showed that theory of mind was significantly related to both reading …

Although monoclonal antibodies have greatly improved cancer therapy, they can trigger side effects due to on-target, off-tumor toxicity. Over the past decade, strategies have emerged to successfully mask the antigen-binding site of antibodies, such that they are only activated at the relevant site, for example, after proteolytic cleavage. However, the methods for designing an ideal affinity-based mask and what parameters are important are not yet well understood. Here, we undertook mechanistic studies using three masks with different properties and identified four critical factors: binding site and affinity, as well as association and dissociation rate constants, which also played an important role. HDX-MS was used to identify the location of binding sites on the antibody, which were subsequently validated by obtaining a high-resolution crystal structure for one of the mask-antibody complexes. These findings will inform …

BackgroundThe relationship between attachment security and psychological distress (such as depressive and anxiety symptoms) is well established. However, the role of attachment security beyond primary attachment, referred to as secondary attachment, and the mechanism underlying this relationship is under-explored among young adults.AimsThis study sought to investigate the effects of primary attachment and secondary attachment on psychological distress with self-esteem as a mediator in young adults.MethodFour hundred and fifty two UK participants aged 18–25 (55.76% females; Mean age = 20.72; SD = 2.29) completed measures of attachment, self-esteem and psychological distress. Using two mediation models, we tested the effects of primary attachment and secondary attachment separately on psychological distress mediated by self-esteem, while controlling for the other type of attachment (i.e …

The caseinolytic protease complex ClpXP is an important house-keeping enzyme in prokaryotes charged with the removal and degradation of misfolded and aggregated proteins and performing regulatory proteolysis. Dysregulation of its function, particularly by inhibition or allosteric activation of the proteolytic core ClpP, has proven to be a promising strategy to reduce virulence and eradicate persistent bacterial infections. Here, we report a rational drug-design approach to identify macrocyclic peptides which allosterically increase proteolysis by ClpP. This work expands the understanding of ClpP dynamics and sheds light on the conformational control exerted by its binding partner, the chaperone ClpX, by means of a chemical approach. The identified macrocyclic peptide ligands may, in the future, serve as a starting point for the development of ClpP activators for antibacterial applications.

Antibody–drug conjugates (ADCs) are valuable therapeutic entities which leverage the specificity of antibodies to selectively deliver cytotoxins to antigen-expressing targets such as cancer cells. However, current methods for their construction still suffer from a number of shortcomings. For instance, using a single modification technology to modulate the drug-to-antibody ratio (DAR) in integer increments while maintaining homogeneity and stability remains exceptionally challenging. Herein, we report a novel method for the generation of antibody conjugates with modular cargo loading from native antibodies. Our approach relies on a new class of disulfide rebridging linkers, which can react with eight cysteine residues, thereby effecting all-in-one bridging of all four interchain disulfides in an IgG1 antibody with a single linker molecule. Modification of the antibody with the linker in a 1 : 1 ratio enabled the modulation …

Background YouTube content has become increasingly popular among children who are not only viewers but producers of this digital medium However, there is no research exploring the use of this medium to aid healthy behaviours. Aims To evaluate how families responded to taking part in an online educational healthy eating intervention by creating YouTube-style digital vlogs. Methods The intervention was delivered online to five families with child/ren aged between 6–16 years. Focus groups were conducted with the families after the intervention to explore their learning and experiences. Findings The families indicated initial challenges in making the vlogs, however, there was evidence of child attitude change and sustained behavioural change as well as enhanced awareness for parents. The families produced vlogs which aimed to educate on and provide a challenge for healthy eating. Conclusions This …

14-3-3 proteins are abundant, intramolecular proteins that play a pivotal role in cellular signal transduction by interacting with phosphorylated ligands. In addition, they are molecular chaperones that prevent protein unfolding and aggregation under cellular stress conditions in a similar manner to the unrelated small heat-shock proteins. In vivo, amyloid β (Aβ) and α-synuclein (α-syn) form amyloid fibrils in Alzheimer’s and Parkinson’s diseases, respectively, a process that is intimately linked to the diseases’ progression. The 14-3-3ζ isoform potently inhibited in vitro fibril formation of the 40-amino acid form of Aβ (Aβ40) but had little effect on α-syn aggregation. Solution-phase NMR spectroscopy of 15N-labeled Aβ40 and A53T α-syn determined that unlabeled 14-3-3ζ interacted preferentially with hydrophobic regions of Aβ40 (L11-H21 and G29-V40) and α-syn (V3-K10 and V40-K60). In both proteins, these regions adopt β-strands within the core of the amyloid fibrils prepared in vitro as well as those isolated from the inclusions of diseased individuals. The interaction with 14-3-3ζ is transient and occurs at the early stages of the fibrillar aggregation pathway to maintain the native, monomeric, and unfolded structure of Aβ40 and α-syn. The N-terminal regions of α-syn interacting with 14-3-3ζ correspond with those that interact with other molecular chaperones as monitored by in-cell NMR spectroscopy.

Antibody–drug conjugates have become one of the most actively developed classes of drugs in recent years. Their great potential comes from combining the strengths of large and small molecule therapeutics: the exquisite specificity of antibodies and the highly potent nature of cytotoxic compounds. More recently, the approach of engineering antibody–drug conjugate scaffolds to achieve highly controlled drug to antibody ratios has focused on substituting or inserting cysteines to facilitate site-specific conjugation. Herein, we characterize an antibody scaffold engineered with an inserted cysteine that formed an unexpected disulfide bridge during manufacture. A combination of mass spectrometry and biophysical techniques have been used to understand how the additional disulfide bridge forms, interconverts, and changes the stability and structural dynamics of the antibody intermediate. This quantitative and …

BackgroundTenofovir disoproxil fumarate (TDF) is associated with reduced bone density in patients with human immunodeficiency virus, but the effect of TDF on bone density in liver transplant (LT) recipients is unknown.MethodsWe performed a single-center, retrospective study of LT recipients with hepatitis B taking TDF compared to a control group with non-hepatitis B virus viral hepatitis. The primary outcome was reduced bone density, defined as femoral neck or lumbar T-score less than −1. Other outcomes included mean T-score and fractures.ResultsThree hundred ninety-three patients were studied: 52 patients in the TDF group and 341 patients in the control group; 64.3% patients in the TDF group had reduced bone density vs 71.4% in the control group (P = .58) before LT, compared to 75% and 81.5% (P = .57), respectively, after LT. Mean posttransplant lumbar T-scores were lower in the TDF group (−1.74 vs …

There are now more than 1700 protein chains that are known to contain some type of topological knot in the protein structure databank. Although this number is small relative to the total number of protein structures solved, it is remarkably high given the fact that for decades it was thought impossible for a protein chain to fold and thread in such a way as to create a knotted structure. There are four different types of knotted protein structures that contain 31, 41, 52 and 61 knots and over the past 15 years there has been an increasing number of experimental and computational studies on these systems. The folding pathways of knotted proteins have been studied in some detail, however, the focus of this review is to address the fundamental question “Why are there knots in proteins?” It is known that once formed, knotted protein structures tend to be conserved by nature. This, in addition to the fact that, at least for some deeply knotted proteins, their folding rates are slow compared with many unknotted proteins, has led to the hypothesis that there are some properties of knotted proteins that are different from unknotted ones, and that this had resulted in some evolutionary advantage over faster folding unknotted structures. In this review, the evidence for and against this theory is discussed. In particular, how a knot within a protein chain may affect the thermodynamic, kinetic, mechanical and cellular (resistance to degradation) stability of the protein is reviewed. c2020 American Mathematical Society