Publications by authors named "Walton P"

Background/objectives: is the third most common sexually transmitted infection (STI), which may become untreatable soon if resistance continues to drastically increase. Due to increases in resistance to recommended antibiotics, alternative sources of novel compounds to combat this threat are being explored. Interestingly, marine sponges have proven to produce a plethora of bioactive compounds that display anticancer, antiviral, antifungal, and antibacterial activity.

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Synthetic polymers are resistant to biological attack, resulting in their long-term accumulation in landfills and in natural aquatic and terrestrial habitats. Lytic polysaccharide monooxygenases (LPMOs) are enzymes which oxidatively cleave the polysaccharide chains in recalcitrant polysaccharides such as cellulose. It has been widely hypothesised that LPMOs could be used to aid in the enzymatic breakdown of synthetic polymers.

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Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that oxidize polysaccharides, leading to their cleavage. LPMOs are classified into eight CAZy families (AA9-11, AA13-17), with the functionality of AA16 being poorly characterized. This study presents biochemical and structural data for an AA16 LPMO (PnAA16) from the marine sponge symbiont Peniophora sp.

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The ISS rodent habitat has provided crucial insights into the impact of spaceflight on mammals, inducing symptoms characteristic of liver disease, insulin resistance, osteopenia, and myopathy. Although these physiological responses can involve the microbiome on Earth, host-microbiota interactions during spaceflight are still being elucidated. We explore murine gut microbiota and host gene expression in the colon and liver after 29 and 56 days of spaceflight using multiomics.

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The discovery of lytic polysaccharide monooxygenases (LPMOs), a family of copper-dependent enzymes that play a major role in polysaccharide degradation, has revealed the importance of oxidoreductases in the biological utilization of biomass. In fungi, a range of redox proteins have been implicated as working in harness with LPMOs to bring about polysaccharide oxidation. In bacteria, less is known about the interplay between redox proteins and LPMOs, or how the interaction between the two contributes to polysaccharide degradation.

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Background: Risky behaviours such as smoking, alcohol consumption, physical inactivity and inadequate consumption of fruits and vegetables are known contributing factors for non-communicable diseases (NCDs) which account for 74% of global mortality. Such behavioural risk factors co-occur frequently resulting in synergistic action for developing NCD related morbidity and mortality. This study aims to assess the existence of multiple risk behaviours and determine the socio-economic and demographic factors associated with co-occurrence of behavioural risks among Myanmar adult population.

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Background: The burden of non-communicable diseases is becoming unmanageable by primary healthcare facilities in low- and middle-income countries. Community-based approaches are promising for supporting healthcare facilities. In Vietnam, community health volunteers are trained in providing health promotion and screening in a culturally adapted training.

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Oxygenase and peroxygenase enzymes generate intermediates at their active sites which bring about the controlled functionalization of inert C-H bonds in substrates, such as in the enzymatic conversion of methane to methanol. To be viable catalysts, however, these enzymes must also prevent oxidative damage to essential active site residues, which can occur during both coupled and uncoupled turnover. Herein, we use a combination of stopped-flow spectroscopy, targeted mutagenesis, TD-DFT calculations, high-energy resolution fluorescence detection X-ray absorption spectroscopy, and electron paramagnetic resonance spectroscopy to study two transient intermediates that together form a protective pathway built into the active sites of copper-dependent lytic polysaccharide monooxygenases (LPMOs).

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This study (1) determined the association of time since initial vaccine regimen, booster dose receipt, and COVID-19 history with antibody titer, as well as change in titer levels over a defined period, and (2) determined risk of COVID-19 associated with low titer levels. This observational study used data from staff participating in the National Football League COVID-19 Monitoring Program. A cohort of staff consented to antibody-focused sub-study, during which detailed longitudinal data were collected.

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Unlabelled: Consent model and intent to donate registries are often the most public facing aspects of an organ and tissue donation and transplantation (OTDT) system. This article describes the output of an international consensus forum designed to give guidance to stakeholders considering reform of these aspects of their system.

Methods: This Forum was initiated by Transplant Québec and cohosted by the Canadian Donation and Transplantation Program partnered with multiple national and international donation and transplantation organizations.

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National registries are used globally to characterise patient demographics, treatment choices and mortality to inform and improve clinical management. Waldenström macroglobulinaemia (WM) is a rare, treatment-responsive B-cell lymphoproliferative disorder with diverse clinical features and variable outcomes. To prospectively chart changes in the management of WM in the UK, the Rory Morrison Registry (RMR) was developed to systematically collect real-world data.

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The copper histidine brace is a structural unit in metalloproteins (Proc Natl Acad Sci USA 2011, 108, 15079). It consists of a copper ion chelated by the NH and π-N atom of an N-terminal histidine, and the τ-N atom of a further histidine, in an overall T-shaped coordination geometry (Nat Catal 2018, 1, 571). Like haem-containing proteins, histidine-brace-containing proteins have peroxygenase and/or oxygenase activity, where the substrates are notable for resistance to oxidation, for example, lytic polysaccharide monooxygenases (LPMOs).

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Unexpected metabolism in modification and conjugation phases can lead to the failure of many late-stage drug candidates or even withdrawal of approved drugs. Thus, it is critical to predict the sites of metabolism (SoM) for enzymes, which interact with drug-like molecules, in the early stages of the research. This study presents methods for predicting the isoform-specific metabolism for human AOs, FMOs, and UGTs and general CYP metabolism for preclinical species.

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LPMOs are enzymes which catalyse the oxidation of a C-H bond within polysaccharides, leading to their oxidative cleavage. To achieve this, LPMOs employ highly reactive oxidising intermediates, the generation of which is likely coupled to substrate binding to the enzyme. The nature of this coupling is unknown.

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The protein mediator of ERBB2-driven cell motility 1 (Memo1) is connected to many signaling pathways that play key roles in cancer. Memo1 was recently postulated to bind copper (Cu) ions and thereby promote the generation of reactive oxygen species (ROS) in cancer cells. Since the concentration of Cu as well as ROS are increased in cancer cells, both can be toxic if not well regulated.

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Wood-feeding termites effectively degrade plant biomass through enzymatic degradation. Despite their high efficiencies, however, individual glycoside hydrolases isolated from termites and their symbionts exhibit anomalously low effectiveness in lignocellulose degradation, suggesting hereto unknown enzymatic activities in their digestome. Herein, we demonstrate that an ancient redox-active enzyme encoded by the lower termite , a Cu/Zn superoxide dismutase (SOD-1), plays a previously unknown role in plant biomass degradation.

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Lytic polysaccharide monooxygenases (LPMOs) are oxidative enzymes found in viruses, archaea, and bacteria as well as eukaryotes, such as fungi, algae and insects, actively contributing to the degradation of different polysaccharides. In Aspergillus nidulans, LPMOs from family AA9 (LPMO9s), along with an AA3 cellobiose dehydrogenase (CDH1), are cosecreted upon growth on crystalline cellulose and lignocellulosic substrates, indicating their role in the degradation of plant cell wall components. Functional analysis revealed that three target LPMO9s (LPMO9C, LPMO9F and LPMO9G) correspond to cellulose-active enzymes with distinct regioselectivity and activity on cellulose with different proportions of crystalline and amorphous regions.

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Background: Rapid COVID-19 testing platforms can identify infected individuals at the point of care (POC), allowing immediate isolation of infected individuals and reducing the risk of transmission. While lab-based nucleic acid amplification testing (NAAT) is often considered the gold standard to detect SARS-CoV-2 in the community, results typically take 2-7 days to return, rendering POC testing a critical diagnostic tool for infection control. The National Football League (NFL) and NFL Players Association deployed a new POC testing strategy using a newly available reverse transcriptase polymerase chain reaction (RT-PCR) rapid test during the 2020 season, and evaluated diagnostic effectiveness compared to other available devices using real-world population surveillance data.

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The active site of the polysaccharide-degrading lytic polysaccharide monooxygenase (LPMO) enzyme features a single copper ion coordinated by a histidine brace. The primary coordination sphere of the copper contains several ligating atoms which are bonded to ionisable protons ( OH, NH), the ps of which are unknown. Using a combination of CW-EPR X-band spectroscopy over a range of pH values and DFT calculations, we show that the active site of a chitin-active AA10 LPMO can exist in three different protonation states (p = 8.

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The nonheme iron(IV)-oxido complex -N3-[(L)FeO(Cl)], where L is a derivative of the tetradentate bispidine 2,4-di(pyridine-2-yl)-3,7-diazabicyclo[3.3.1]nonane-1-one, has an = 1 electronic ground state and is the most reactive nonheme iron model system known so far, of a similar order of reactivity as nonheme iron enzymes (C-H abstraction of cyclohexane, -90 °C (propionitrile), = 3.

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Objectives: Fear and risk of precipitated withdrawal are barriers for initiating buprenorphine in individuals with opioid use disorder, particularly among those using fentanyl. A buprenorphine rapid overlap initiation (ROI) protocol (also knownas "rapidmicro-dosing") utilizing small, escalating doses of buprenorphine can overcome this barrier, reaching therapeutic doses in 3 to 4 days. We sought to demonstrate the feasibility of implementing a buprenorphine ROI protocol for buprenorphine initiation in the outpatient setting.

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Ischemic stroke often co-occurs with Alzheimer's disease (AD) leading to a worsened clinical outcome. Neuroinflammation is a critical process implicated in AD and ischemic pathology, associated with cognitive decline. We sought to investigate the combined effects of ischemic stroke induced by endothelin-1 injection in two AD rat models, using motor function, memory and microglial inflammation in the basal forebrain and striatum as readouts.

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Pseudomonas putida W619 is a soil Gram-negative bacterium commonly used in environmental studies thanks to its ability in degrading many aromatic compounds. Its genome contains several putative carbohydrate-active enzymes such as glycoside hydrolases and lytic polysaccharide monooxygenases (PMOs). In this study, we have heterologously produced in Escherichia coli and characterized a new enzyme belonging to the AA10 family, named PpAA10 (Uniprot: B1J2U9), which contains a chitin-binding type-4 module and showed activity toward β-chitin.

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