Biology subjects

Gethings, L. A.

Publications and source records attributed to Gethings, L. A..

3 recordsLinked to original sources

bioRxiv2026

Advances in the Design and Functionality of a Compact Multi-Reflecting Time-of-Flight Mass Spectrometer

AO_SCPLOWBSTRACTC_SCPLOWO_ST_ABSRationaleC_ST_ABSHigh-resolution mass spectrometry is routinely used for the analysis of complex samples in pharmaceutical, environmental, and omics related studies. Such applications demand instrumentation to be capable of combining sub-ppm mass accuracy, high resolving power, rapid full m/z range acquisition, over a wide dynamic range. MethodsAchieving the above requirements places constraints on analyzer design and performance. Multi-reflecting time-of-flight (MRT) based analyzers have previously been reported as a means of significantly extending the effective flight path in compact TOF designs. Here, further instrument and functionality advances in a compact MRT mass spectrometer design are described. ResultsThe impact of these enhancements was assessed for targeted and non-targeted omics applications, examining the impact of acquisition speed on resolving power, dynamic range including limits of quantitation, and quantitative precision. ConclusionThe results obtained characterize the performance of the enhanced design features of a compact MRT mass spectrometer. Operation at elevated acquisition rates up to 200 Hz was observed without loss in resolving power, isotopic ratio accuracy, or quantitative precision.

biochemistry↗

bioRxiv2022

Lipidomic analysis reveals differences in Bacteroides species driven largely by plasmalogens, glycerophosphoinositols and certain sphingolipids

There has been increasing interest in bacterial lipids in recent years due, in part, to their emerging role as molecular signalling molecules. Bacteroides thetaiotaomicron is an important member of the mammalian gut microbiota that has been shown to produce sphingolipids (SP) that pass through the gut epithelial barrier to impact host SP metabolism and signal into host inflammation pathways. B. thetaiotaomicron also produces a novel family of N-acyl amines (called glycine lipids) that are potent ligands of host Toll-like receptor 2 (TLR2). Here, we specifically examine the lipid signatures of 4 species of gut associated Bacteroides. In total we identify 170 different lipids and we report that the range and diversity of Bacteroides lipids is species-specific. Multi-variate analysis reveals that the differences in the lipid signatures are largely driven by the presence/absence of plasmalogens, glycerophosphoinositols and certain SP. Moreover, we show that, in B. thetaiotaomicron, mutations altering either SP or glycine lipid biosynthesis results in significant changes in the levels of other lipids suggesting the existence of compensatory mechanisms required to maintain the functionality of the bacterial membrane. ImportanceBacteroides are important beneficial members of the gut microbiome that produce lipids that can function as cross-kingdom signalling molecules. We describe, for the first time, a comprehensive and qualitative comparison of the lipid signatures of 4 important Bacteroides species. We identify a group of Bacteroides core lipids and uncover species-specific differences in plasmalogen, glycerophospholipid and SP metabolism with more subtle differences observed in glycine lipid production. This data will provide a useful platform for the further characterisation of the lipid-based host-microbe dialogue and the influence of microbial lipids on host health and disease states.

microbiology↗

bioRxiv2018

Tracking dynamic changes in Alzheimer’s disease brain proteome reveals ageing-independent damage in Drosophila

Alzheimers disease (AD), the most prevalent form of dementia, is a progressive and devastating neurodegenerative condition for which there are no effective treatments. Understanding the molecular pathology of AD during disease progression may identify new ways to reduce neuronal damage. Here, we present a longitudinal study tracking dynamic proteomic alterations in the brains of an inducible Drosophila melanogaster model of AD expressing the Arctic mutant A{beta}42 gene. We identified 3093 proteins from flies that were induced to express A{beta}42 and age-matched healthy controls using label-free quantitative ion-mobility data independent analysis mass spectrometry. Of these, 228 proteins were significantly altered by A{beta}42 accumulation and were enriched for AD-associated processes. Network analyses further revealed that these proteins have distinct hub and bottleneck properties in the brain protein interaction network, suggesting that several may have significant effects on brain function. Our unbiased analysis provides useful insights into the key processes governing the progression of amyloid toxicity and forms a basis for further functional analyses in model organisms and translation to mammalian systems.

biochemistry↗