Alfred Thumser

Dr Alfred Thumser


Senior Teaching Fellow in Biochemistry
BSc, BSc(Med)(Hons), PhD
+44 (0)1483 686383
26 AY 04

Academic and research departments

School of Biosciences and Medicine.

Biography

Areas of specialism

Biochemistry

Courses I teach on

Undergraduate

My publications

Publications

Beecroft NJ, Zhao F, Varcoe JR, Slade RCT, Thumser AE, Avignone-Rossa C (2012) Dynamic changes in the microbial community composition in microbial fuel cells fed with sucrose, Applied Microbiology and Biotechnology 93 (1) pp. 423-437 Springer
The performance and dynamics of the bacterial communities in the biofilm and suspended culture in the anode chamber of sucrose-fed microbial fuel cells (MFCs) were studied by using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rRNA genes followed by species identification by sequencing. The power density of MFCs was correlated to the relative proportions of species obtained from DGGE analysis in order to detect bacterial species or taxonomic classes with important functional role in electricity production. Although replicate MFCs showed similarity in performance, cluster analysis of DGGE profiles revealed differences in the evolution of bacterial communities between replicate MFCs. No correlation was found between the proportion trends of specific species and the enhancement of power output. However, in all MFCs, putative exoelectrogenic denitrifiers and sulphate-reducers accounted for approximately 24% of the bacterial biofilm community at the end of the study. Pareto-Lorenz evenness distribution curves extracted from the DGGE patterns obtained from time course samples indicated community structures where shifts between functionally similar species occur, as observed within the predominant fermentative bacteria. These results suggest the presence of functional redundancy within the anodic communities, a probable indication that stable MFC performance can be maintained in changing environmental conditions. The capability of bacteria to adapt to electricity generation might be present among a wide range of bacteria.
Wu X, Rahunen N, Zhao F, Varcoe J, Avignone-Rossa C, Thumser A, Slade R (2010) Periplasmic hydrogenases role for extracellular electron transfer, ACS National Meeting Book of Abstracts
Sihra JK, Mulholland DA, Langat MK, Crouch NR, Nuzillard J-M, Thumser AE (2012) NOVEL TRITERPENOID DERIVATIVES FROM EUCOMIS BICOLOR (HYACINTHACEAE: HYACINTHOIDEAE), PHARMACEUTICAL BIOLOGY 50 (5) pp. 645-645
Davies SK, Ang JE, Revell VL, Holmes B, Mann A, Robertson FP, Cui N, Middleton B, Ackermann K, Kayser M, Thumser AE, Raynaud FI, Skene DJ (2014) Effect of sleep deprivation on the human metabolome., Proc Natl Acad Sci U S A 111 (29) pp. 10761-10766
Sleep restriction and circadian clock disruption are associated with metabolic disorders such as obesity, insulin resistance, and diabetes. The metabolic pathways involved in human sleep, however, have yet to be investigated with the use of a metabolomics approach. Here we have used untargeted and targeted liquid chromatography (LC)/MS metabolomics to examine the effect of acute sleep deprivation on plasma metabolite rhythms. Twelve healthy young male subjects remained in controlled laboratory conditions with respect to environmental light, sleep, meals, and posture during a 24-h wake/sleep cycle, followed by 24 h of wakefulness. Two-hourly plasma samples collected over the 48 h period were analyzed by LC/MS. Principal component analysis revealed a clear time of day variation with a significant cosine fit during the wake/sleep cycle and during 24 h of wakefulness in untargeted and targeted analysis. Of 171 metabolites quantified, daily rhythms were observed in the majority (n = 109), with 78 of these maintaining their rhythmicity during 24 h of wakefulness, most with reduced amplitude (n = 66). During sleep deprivation, 27 metabolites (tryptophan, serotonin, taurine, 8 acylcarnitines, 13 glycerophospholipids, and 3 sphingolipids) exhibited significantly increased levels compared with during sleep. The increased levels of serotonin, tryptophan, and taurine may explain the antidepressive effect of acute sleep deprivation and deserve further study. This report, to our knowledge the first of metabolic profiling during sleep and sleep deprivation and characterization of 24 h rhythms under these conditions, offers a novel view of human sleep/wake regulation.
Thumser AEA, Buckland AG, Wilton DC (1998) Monoacylglycerol binding to human serum albumin: Evidence that monooleoylglycerol binds at the dansylsarcosine site, JOURNAL OF LIPID RESEARCH 39 (5) pp. 1033-1038 LIPID RESEARCH INC
IVANETICH KM, THUMSER AEA, HARRISON GG (1988) HALOTHANE - INHIBITION AND ACTIVATION OF RAT HEPATIC GLUTATHIONE S-TRANSFERASES, BIOCHEMICAL PHARMACOLOGY 37 (10) pp. 1903-1908 PERGAMON-ELSEVIER SCIENCE LTD
Storch J, Thumser AE (2010) Tissue-specific functions in the fatty acid-binding protein family., J Biol Chem 285 (43) pp. 32679-32683
The intracellular fatty acid-binding proteins (FABPs) are abundantly expressed in almost all tissues. They exhibit high affinity binding of a single long-chain fatty acid, with the exception of liver FABP, which binds two fatty acids or other hydrophobic molecules. FABPs have highly similar tertiary structures consisting of a 10-stranded antiparallel ²-barrel and an N-terminal helix-turn-helix motif. Research emerging in the last decade has suggested that FABPs have tissue-specific functions that reflect tissue-specific aspects of lipid and fatty acid metabolism. Proposed roles for FABPs include assimilation of dietary lipids in the intestine, targeting of liver lipids to catabolic and anabolic pathways, regulation of lipid storage and lipid-mediated gene expression in adipose tissue and macrophages, fatty acid targeting to ²-oxidation pathways in muscle, and maintenance of phospholipid membranes in neural tissues. The regulation of these diverse processes is accompanied by the expression of different and sometimes multiple FABPs in these tissues and may be driven by protein-protein and protein-membrane interactions.
Thumser AE, Rashed AA, Sharp PA, Lodge JK (2010) Ascorbate enhances iron uptake into intestinal cells through formation of a FeCl3-ascorbate complex, Food Chemistry 123 (2) pp. 281-285 ELSEVIER
It has been well documented that ascorbate enhances iron uptake, with a proposed mechanism based on reduction to the more absorbable ferrous form. We have performed a study on the effects of ascorbate on ferric iron uptake in the human epithelial Caco-2 cell-line. Ascorbate increased uptake in a concentration-dependent manner with a significant difference between iron uptake and reduction. Uptake kinetics are characteristic of a non-essential activator and the formation of an Fe3+?ascorbate complex. This investigation provides evidence that ascorbate enhances the apical uptake of ferric iron into Caco-2 cells through the formation of a Fe3+?ascorbate complex.
ADAMS PA, THUMSER AEA (1993) HEME-PEPTIDE-PROTEIN INTERACTIONS .5. THE HEME UNDECAPEPTIDE MICROPEROXIDASE-11 (FE3+MP-11) HUMAN SERUM-ALBUMIN (HSA) REACTION IN AQUEOUS METHANOLIC SOLUTION - A SIMPLE SYSTEM DEMONSTRATING THE EFFECT OF HYDROPHOBICITY ON LIGAND RELEASE FROM A LIGAND-PROTEIN COMPLEX, JOURNAL OF INORGANIC BIOCHEMISTRY 50 (1) pp. 1-7 ELSEVIER SCIENCE INC
Milton RD, Slade RCT, Giroud F, Minteer SD, Thumser AE (2013) Hydrogen peroxide produced by glucose oxidase affects the performance of laccase cathodes in glucose/oxygen fuel cells: FAD-dependent glucose dehydrogenase as a replacement, Physical Chemistry Chemical Physics 15 (44) pp. 19371-19379
Hydrogen peroxide production by glucose oxidase (GOx) and its negative effect on laccase performance have been studied. Simultaneously, FAD-dependent glucose dehydrogenase (FAD-GDH), an O-insensitive enzyme, has been evaluated as a substitute. Experiments focused on determining the effect of the side reaction of GOx between its natural electron acceptor O (consumed) and hydrogen peroxide (produced) in the electrolyte. Firstly, oxygen consumption was investigated by both GOx and FAD-GDH in the presence of substrate. Relatively high electrocatalytic currents were obtained with both enzymes. O consumption was observed with immobilized GOx only, whilst O concentration remained stable for the FAD-GDH. Dissolved oxygen depletion effects on laccase electrode performances were investigated with both an oxidizing and a reducing electrode immersed in a single compartment. In the presence of glucose, dramatic decreases in cathodic currents were recorded when laccase electrodes were combined with a GOx-based electrode only. Furthermore, it appeared that the major loss of performance of the cathode was due to the increase of HO concentration in the bulk solution induced laccase inhibition. 24 h stability experiments suggest that the use of O-insensitive FAD-GDH as to obviate in situ peroxide production by GOx is effective. Open-circuit potentials of 0.66 ± 0.03 V and power densities of 122.2 ± 5.8 ¼W cm were observed for FAD-GDH/laccase biofuel cells. © 2013 the Owner Societies.
Khodadadi I, Plant NJ, Mersinias V, Thumser AE (2010) Applicability of the P19CL6 cells as a model of cardiomyocytes - A transcriptome analysis, Health 2 (1) pp. 24-31
Devonshire AS, Plant NJ, Thumser AE (2007) Influence of metabolic stimuli on transcriptional regulation by Hepatocyte Nuclear Factor 4 alpha, DIABETOLOGIA 50 pp. S238-S239 SPRINGER
Plant K, Thumser A, Plant N (2006) Evolution of the fatty acid-binding protein family: An ordered increase in gene number, correlating to more refined mechanisms of lipid processing, TOXICOLOGY 226 (1) pp. 73-74 ELSEVIER IRELAND LTD
Thumser AEA, Wilton DC (1996) The binding of cholesterol and bile salts to recombinant rat liver fatty acid-binding protein, BIOCHEMICAL JOURNAL 320 pp. 729-733 PORTLAND PRESS
Thumser AEA, Voysey J, Wilton DC (1997) A fluorescence displacement assay for the measurement of arachidonoyl ethanolamide (anandamide) and oleoyl amide (octadecenoamide) hydrolysis, BIOCHEMICAL PHARMACOLOGY 53 (3) pp. 433-435 PERGAMON-ELSEVIER SCIENCE LTD
IVANETICH KM, THUMSER AEA, PHILLIPS SE, SIKAKANA CNT (1990) REVERSIBLE INHIBITION OF RAT HEPATIC GLUTATHIONE-S-TRANSFERASE 1-2 BY BILIRUBIN, BIOCHEMICAL PHARMACOLOGY 40 (7) pp. 1563-1568 PERGAMON-ELSEVIER SCIENCE LTD
Davies JK, Thumser AEA, Wilton DC (1999) Binding of recombinant rat liver fatty acid-binding protein to small anionic phospholipid vesicles results in ligand release: A model for interfacial binding and fatty acid targeting, BIOCHEMISTRY 38 (51) pp. 16932-16940 AMER CHEMICAL SOC
Efthimiou G, Thumser AE, Avignone-Rossa CA (2008) A novel finding that Streptomyces clavuligerus can produce the antibiotic clavulanic acid using olive oil as a sole carbon source, JOURNAL OF APPLIED MICROBIOLOGY 105 (6) pp. 2058-2064 WILEY-BLACKWELL PUBLISHING, INC
IVANETICH KM, THUMSER AEA (1987) REVERSIBLE INHIBITION AND ACTIVATION OF HEPATIC GSH S-TRANSFERASES BY ETHYLENE DIBROMIDE, PHARMACOLOGY & THERAPEUTICS 33 (1) pp. 85-88 PERGAMON-ELSEVIER SCIENCE LTD
Thumser AEA, Voysey J, Wilton DC (1996) Mutations of recombinant rat liver fatty acid-binding protein at residues 102 and 122 alter its structural integrity and affinity for physiological ligands, BIOCHEMICAL JOURNAL 314 pp. 943-949 PORTLAND PRESS
Thumser AE, Moore JB, Plant NJ (2014) Fatty acid binding proteins: Tissue-specific functions in health and disease, Current Opinion in Clinical Nutrition and Metabolic Care 17 (2) pp. 124-129
Purpose of review The purpose of this study is to review recent evidence for the role of the cytosolic fatty acid binding proteins (FABPs) as central regulators of whole-body metabolic control. Recent findings Dysregulated FABPs have been associated with a number of diseases, including obesity and nonalcoholic fatty liver disease (FABP1, FABP2, FABP4), cardiovascular risk (FABP3) and cancer (FABP5, FABP7). As underlying mechanisms become better understood, FABPs may represent novel biomarkers for therapeutic targets. In addition, the role of FABPs as important signalling molecules has also been highlighted in recent years; for example, FABP3 may act as a myokine, matching whole-body metabolism to muscular energy demands and FABP4 functions as an adipokine in regulating macrophage and adipocyte interactions during inflammation. Summary In addition to their traditional role as fatty acid trafficking proteins, increasing evidence supports the role of FABPs as important controllers of global metabolism, with their dysregulation being linked to a host of metabolic diseases. Copyright © Lippincott Williams & Wilkins.
THUMSER AEA, EVANS C, WORRALL AF, WILTON DC (1994) EFFECT ON LIGAND-BINDING OF ARGININE MUTATIONS IN RECOMBINANT RAT-LIVER FATTY-ACID-BINDING PROTEIN, BIOCHEMICAL JOURNAL 297 pp. 103-107 PORTLAND PRESS
Forster S, Thumser AE, Hood SR, Plant NJ (2012) Characterization of Rhodamine-123 as a Tracer Dye for Use In In vitro Drug Transport Assays, PLoS One 7 (3) e33253 Public Library of Science
Fluorescent tracer dyes represent an important class of sub-cellular probes and allow the examination of cellular processes in real-time with minimal impact upon these processes. Such tracer dyes are becoming increasingly used for the examination of membrane transport processes as they are easy-to-use, cost effective probe substrates for a number of membrane protein transporters. Rhodamine 123, a member of the rhodamine family of flurone dyes, has been used to examine membrane transport by the ABCB1 gene product, MDR1. MDR1 is viewed as the archetypal drug transport protein, and is able to efflux a large number of clinically relevant drugs. In addition, ectopic activity of MDR1 has been associated with the development of multiple drug resistance phenotype, which results in a poor patient response to therapeutic intervention. It is thus important to be able to examine the potential for novel compounds to be MDR1 substrates. Given the increasing use rhodamine 123 as a tracer dye for MDR1, a full characterisation of its spectral properties in a range of in vitro assay-relevant media is warranted. Herein, we determine »max for excitation and emission or rhodamine 123 and its metabolite rhodamine 110 in commonly used solvents and extraction buffers, demonstrating that fluorescence is highly dependent on the chemical environment: Optimal parameters are 1% (v/v) methanol in HBSS, with »ex=505nm, »em=525nm. We characterise the uptake of rhodamine 123 into cells, via both passive and active processes, and demonstrate that this occurs primarily through OATP1A2-mediated facilitated transport at concentrations below 2µM, and via micelle-mediated passive diffusion above this. Finally, we quantify the intracellular sequestration and metabolism of rhodamine 123, demonstrating that these are both cell line-dependent factors that may influence the interpretation of transport assays.
Wu X, Zhao F, Varcoe JR, Thumser AE, Avignone-Rossa C, Slade RCT (2009) Direct electron transfer of glucose oxidase immobilized in an ionic liquid reconstituted cellulose-carbon nanotube matrix, BIOELECTROCHEMISTRY 77 (1) pp. 64-68 ELSEVIER SCIENCE SA
THUMSER AEA, WILTON DC (1995) THE BINDING OF NATURAL AND FLUORESCENT LYSOPHOSPHOLIPIDS TO WILD-TYPE AND MUTANT RAT-LIVER FATTY-ACID-BINDING PROTEIN AND ALBUMIN, BIOCHEMICAL JOURNAL 307 pp. 305-311 PORTLAND PRESS
Sanat F, Howe K, Coleman T, Thumser A, Plant N (2009) Impact of transporter-mediated uptake on statin-induced gene expression in human Huh7 cells, TOXICOLOGY 262 (1) pp. 20-21 ELSEVIER IRELAND LTD
THUMSER AEA, ADAMS PA (1994) HEME PEPTIDE/PROTEIN INTERACTION .6. THE KINETIC MECHANISMS OF THE INTERACTIONS WITH, AND INHIBITION OF ENZYMATIC-ACTIVITY OF THE HUMAN ERYTHROCYTE GLUTATHIONE-S-TRANSFERASE ISOENZYME-RHO-(P), BY HEME OCTAPEPTIDE, NONAPEPTIDE, AND UNDECAPEPTIDE MP-8/-9/-11, JOURNAL OF INORGANIC BIOCHEMISTRY 53 (3) pp. 157-168 ELSEVIER SCIENCE INC
Milton RD, Giroud F, Thumser AE, Minteer SD, Slade RCT (2014) Glucose oxidase progressively lowers bilirubin oxidasebioelectrocatalytic cathode performance in single-compartmentglucose/oxygen biological fuel cells, Electrochimica Acta 140 pp. 59-64
Enzymatic biological fuel cells (E-BFCs) were prepared using glucose oxidase (GOx) or FAD-dependentglucose dehydrogenase (FAD-GDH) as the anodic enzyme, coupled with direct electrocatalytic biliru-bin oxidase (BOd) biocathodes obtained via incorporation of anthracene-modified multi-walled carbonnanotubes (Ac-MWCNTs). For GOx/BOd E-BFCs operating at pH 6.5 (200 mM glucose), open-circuit poten-tials, maximum current densities and maximum power densities of 0.47 ± 0.02 V, 332.7 ± 19.6 ¼A cm-2,and 46.5 ± 2.8 ¼W cm-2were observed. For FAD-GDH/BOd E-BFCs operating in the same conditions,open-circuit potentials, maximum current densities and maximum power densities of 0.40 ± 0.01 V,226.6 ± 8.0 ¼A cm-2, and 35.9 ± 1.3 ¼W cm-2were observed. The effect of H2O 2(as produced by theenzymatic side-reaction of GOx) on BOd bioelectrocatalytic cathodes in E-BFCs was also investigated.Short-term testing (steady state) revealed that GOx did not produce significant quantities of H2O2toaffect BOd biocathodes. However, long-term testing (steady state, 24 hours) revealed that the quantityof H2O2produced by GOx is large enough to have detrimental effects on the performance of the E-BFCs.© 2014 Published by Elsevier Ltd.
Zhao F, Rahunen N, Varcoe JR, Chandra A, Avignone-Rossa C, Thumser AE, Slade RCT (2008) Activated carbon cloth as anode for sulfate removal in a microbial fuel cell, ENVIRONMENTAL SCIENCE & TECHNOLOGY 42 (13) pp. 4971-4976 AMER CHEMICAL SOC
Thumser AEA, Tsai J, Storch J (2001) Collision-mediated transfer of long-chain fatty acids by neural tissue fatty acid-binding proteins (FABP) - Studies with fluorescent analogs, JOURNAL OF MOLECULAR NEUROSCIENCE 16 (2-3) pp. 143-150 HUMANA PRESS INC
Sier JH, Thumser AE, Plant NJ (2014) THE DEVELOPMENT OF A UPLC-MS METHOD FOR THE DETECTION OF 17SS-ESTRADIOL AND ITS METABOLITES IN CELL SAMPLES TO EXAMINE METABOLISM-TRANSPORTER INTERACTION, DRUG METABOLISM REVIEWS 45 pp. 239-239 INFORMA HEALTHCARE
Ahmed AESI, Wardell JN, Thumser AE, Avignone-Rossa CA, Cavalli G, Hay JN, Bushell ME (2011) Metabolomic Profiling Can Differentiate Between Bactericidal Effects of Free and Polymer Bound Halogen, Journal of Applied Polymer Science 119 (2) pp. 709-718 Wiley-Blackwell
The effects of two halogenated compounds (sodium hypochlorite and N-halamine polymers) on the Escherichia coli metabolome were investigated. Changes in the intracellular metabolite pools of bacterial cells treated with different formulations of these compounds were analysed using FTIR (Fourier Transform Infra Red) spectroscopy and LC-MS (Liquid Chromatography-Mass Spectroscopy). Principal component analysis was used to generate metabolic profiles of the intracellular metabolites to investigate the effect of sublethal concentrations on the metabolome of treated cells. The effect of treatment with sodium hypochlorite was quantitatively dependent on the exposure time. The resulting metabolic profiles supported our previous hypothesis that the mode of action of some halogenated compounds, such as N-halamine polymers, can be initiated by release of halogen ions into the aqueous environment, in addition to direct contact between the solid polymer material and the bacterial cells. Moreover, the metabolic profiles were able to differentiate between the effect of free and polymer-bound halogen. Our metabolomic approach was used for hypothesis generation to distinguish apparently different bactericidal effects of free and polymer-bound halogen.
The therapeutic class of HMG-CoA reductase inhibitors, the statins are central agents in the treatment of hypercholesterolaemia and the associated conditions of cardiovascular disease, obesity and metabolic syndrome. Although statin therapy is generally considered safe, a number of known adverse effects do occur, most commonly treatment-associated muscular pain. In vitro evidence also supports the potential for drug-drug interactions involving this class of agents, and to examine this a ligand-binding assay was used to determine the ability of six clinically used statins for their ability to directly activate the nuclear receptors pregnane X-receptor (PXR), farnesoid X-receptor (FXR) and constitutive androstane receptor (CAR), demonstrating a relative activation of PXR>FXR>CAR. Using reporter gene constructs, we demonstrated that this order of activation is mirrored at the transcriptional activation level, with PXR-mediated gene activation being pre-eminent. Finally, we described a novel regulatory loop, whereby activation of FXR by statins increases PXR reporter gene expression, potentially enhancing PXR-mediated responses. Delineating the molecular interactions of statins with nuclear receptors is an important step in understanding the full biological consequences of statin exposure. This demonstration of their ability to directly activate nuclear receptors, leading to nuclear receptor cross-talk, has important potential implications for their use within a polypharmacy paradigm.
Milton RD, Baur J, Varcoe JR, Thumser AE, Slade RC (2012) An optimised glucose oxidase bioelectrode exhibiting high performance direct electron transfer., Phys Chem Chem Phys 14 (27) pp. 9582-9585 Royal Society of Chemistry
A glucose oxidase (GOd) bioelectrode exhibiting high performance, direct electron transfer (DET) has been prepared. Unprecedented redox peak current densities of 1 mA cm(-2) were observed alongside a clear electrochemical response to glucose. This system shows potential as a low cost, high performance enzymatic bioelectrode.
THUMSER AEA, IVANETICH KM (1993) KINETIC MECHANISM OF HUMAN ERYTHROCYTE ACIDIC ISOENZYME-RHO, BIOCHIMICA ET BIOPHYSICA ACTA 1203 (1) pp. 115-120 ELSEVIER SCIENCE BV
Green RCE, Thumser AE, Povey D, Saldanha JW, Potter BS, Palmer RA, Howlin BJ (2009) A comparative study of the single crystal X-ray determination and molecular modelling of the binding of oligomycin to ATP Synthase, Computational Biology and Chemistry 33 (3) pp. 189-195 ELSEVIER SCI LTD
Recently published X-ray structures of three common forms, A, B and C, of oligomycin, including absolute configurations, are investigated to examine their binding to ATP Synthase. The X-ray studies reveal regions with differences in three-dimensional structure and hydrogen bonding propensity between the oligomycins, which may be associated with their potential to bind to sites on ATP Synthase. Computational docking studies carried out using MOE with the X-ray structures and an homology model of the FO domain of ATP Synthase from Escherichia coli, are used to derive an induced fit pocket. Docking of all oligomycins to this pocket indicate that the B and C forms bind more tightly than the A form. Consideration of the single crystal X-ray data alone indicate the B form may be the best inhibitor and that O(24) is the most important ligating group for binding, this is supported by the docking data. The latter reveals Asn214 and other key proton translocating residues to be the main residues contacted by the inhibitor. These data allow the binding modes of different forms of oligomycin to be deduced from X-ray single crystal data supported by molecular modelling and computational docking studies.
THUMSER AEA, VOYSEY JE, WILTON DC (1994) THE BINDING OF LYSOPHOSPHOLIPIDS TO RAT-LIVER FATTY-ACID-BINDING PROTEIN AND ALBUMIN, BIOCHEMICAL JOURNAL 301 pp. 801-806 PORTLAND PRESS
Tunbridge CP, Crouch NR, Thumser AE, Mulholland DA (2012) COX-2 SPECIFIC INHIBITORS FROM LEDEBOURIA OVATIFOLIA AND LEDEBOURIA SOCIALIS (HYACINTHACEAE:HYACINTHOIDEAE), PHARMACEUTICAL BIOLOGY 50 (5) pp. 569-569
Thumser AE, Storch J (2007) Characterization of a BODIPY-labeled fluorescent fatty acid analogue. Binding to fatty acid-binding proteins, intracellular localization, and metabolism., Mol Cell Biochem 299 (1-2) pp. 67-73
The BODIPY-labeled fatty acid analogues are a useful addition to the tools employed to study the cellular uptake and metabolism of lipids. In this study, we show that BODIPY FL C(16) binds to purified liver and intestinal fatty acid-binding proteins with high affinity at a site similar to that for the physiological fatty acid oleic acid. Further, in human intestinal Caco-2 cells BODIPY FL C(16) co-localizes extensively with mitochondria, endoplasmic reticulum/Golgi, and L-FABP. Virtually no esterification of BODIPY FL C(16) was observed under the experimental conditions employed. We conclude that BODIPY FL C(16) may be a useful tool for studying the distribution and function of FABPs in a cellular environment.
Ang JE, Revell V, Mann A, Mäntele S, Otway DT, Johnston JD, Thumser AE, Skene DJ, Raynaud F (2012) Identification of Human Plasma Metabolites Exhibiting Time-of-Day Variation Using an Untargeted Liquid Chromatography-Mass Spectrometry Metabolomic Approach., Chronobiol Int 29 (7) pp. 868-881 Informa Healthcare
Although daily rhythms regulate multiple aspects of human physiology, rhythmic control of the metabolome remains poorly understood. The primary objective of this proof-of-concept study was identification of metabolites in human plasma that exhibit significant 24-h variation. This was assessed via an untargeted metabolomic approach using liquid chromatography-mass spectrometry (LC-MS). Eight lean, healthy, and unmedicated men, mean age 53.6 (SD ± 6.0) yrs, maintained a fixed sleep/wake schedule and dietary regime for 1 wk at home prior to an adaptation night and followed by a 25-h experimental session in the laboratory where the light/dark cycle, sleep/wake, posture, and calorific intake were strictly controlled. Plasma samples from each individual at selected time points were prepared using liquid-phase extraction followed by reverse-phase LC coupled to quadrupole time-of-flight MS analysis in positive ionization mode. Time-of-day variation in the metabolites was screened for using orthogonal partial least square discrimination between selected time points of 10:00 vs. 22:00 h, 16:00 vs. 04:00 h, and 07:00 (d 1) vs. 16:00 h, as well as repeated-measures analysis of variance with time as an independent variable. Subsequently, cosinor analysis was performed on all the sampled time points across the 24-h day to assess for significant daily variation. In this study, analytical variability, assessed using known internal standards, was low with coefficients of variation
Enzymatic biological fuel cells (E-BFCs) were prepared using glucose oxidase (GOx) or FAD-dependent glucose dehydrogenase (FAD-GDH) as the anodic enzyme, coupled with direct electrocatalytic bilirubin oxidase (BOd) biocathodes obtained via incorporation of anthracene-modified multi-walled carbon nanotubes (Ac-MWCNTs). For GOx/BOd E-BFCs operating at pH 6.5 (200 mM glucose), open-circuit potentials, maximum current densities and maximum power densities of 0.47 ± 0.02 V, 332.7 ± 19.6 ¼A cm, and 46.5 ± 2.8 ¼W cm were observed. For FAD-GDH/BOd E-BFCs operating in the same conditions, open-circuit potentials, maximum current densities and maximum power densities of 0.40 ± 0.01 V, 226.6 ± 8.0 ¼A cm, and 35.9 ± 1.3 ¼W cm were observed. The effect of HO (as produced by the enzymatic side-reaction of GOx) on BOd bioelectrocatalytic cathodes in E-BFCs was also investigated. Short-term testing (steady state) revealed that GOx did not produce significant quantities of HO to affect BOd biocathodes. However, long-term testing (steady state, 24 hours) revealed that the quantity of HO produced by GOx is large enough to have detrimental effects on the performance of the E-BFCs. © 2014.
Tunbridge CP, Crouch NR, Thumser AE, Mulholland DA (2012) COX-2 SPECIFIC INHIBITION FROM NATURAL PRODUCT (E)-HINOKIRESINOL AND A FACILE SYNTHESIS OF 3-VINYLPHENYLINDANES, PHARMACEUTICAL BIOLOGY 50 (5) pp. 649-649
Skene DJ, Davies SK, Ang JE, Revell VL, Holmes B, Mann A, Robertson R, Cui N, Middleton B, Ackermann K, Kayser M, Thumser AE, Raynaud FI (2014) Effect of sleep deprivation on human plasma metabolome rhythms, JOURNAL OF SLEEP RESEARCH 23 pp. 36-37 WILEY-BLACKWELL
The bulbs of Ledebouria socialis (Hyacinthaceae) yielded the benzocyclobutene homoisoflavonoid, (R)-2',5-dihydroxy-3',4',7-trimethoxyspiro{2H-1-benzopyran-3-(4H)-9-bicyclo[4.2.0]octa[1,3,5]triene}-4-one, socialinone (1). Ledebouria ovatifolia yielded (2µ,3R)-2,5-dihydroxy-7-methoxyspiro[2H-1-benzopyran-3(4H), 5'(6'H)-cyclobuta[f][1,3]benzodioxol]-4-one (2) and the homoisoflavanone, (E)-3-(3',4'-dihydroxybenzylidene)-5,7-dihydroxychroman-4-one, ovatifolionone (5), the dihydrochalcone, 4,4'-dihydroxy-2',6'-dimethoxydihydrochalcone (3), and xanthone, 1,6-dihydroxy-2,3,5-trimethoxy-8-methyl-9H-xanthen-9-one (4) along with 21 known compounds. Structures were determined using spectroscopic techniques. The anti-inflammatory activities of the homoisoflavonoids and xanthones isolated were evaluated against cyclooxygenase-1 and -2 isoenzymes. (R)-3-(3',4'-Dihydroxybenzyl)-7-hydroxy-5-methoxychroman-4-one (7), (E)-3-(3',4'-dihydroxybenzylidene)-7-hydroxy-5-methoxychroman-4-one (10), 1,3,6-trihydroxy-2-methoxy-8-methylxanthen-9-one (6) and ovatifolionone acetate (5Ac) exhibited significant activity against cyclooxygenase-2 at
Thumser AEA, Storch J (2000) Liver and intestinal fatty acid-binding proteins obtain fatty acids from phospholipid membranes by different mechanisms, JOURNAL OF LIPID RESEARCH 41 (4) pp. 647-656 LIPID RESEARCH INC
Davies JK, Thumser AEA, Wilton DC (1998) Liver fatty acid binding protein (FABP) binds to anionic phospholipid vesicles with release of ligand, BIOCHEMICAL SOCIETY TRANSACTIONS 26 (3) pp. S238-S238 PORTLAND PRESS
Wu X, Zhao F, Varcoe JR, Thumser AE, Avignone-Rossa C, Slade RCT (2009) A one-compartment fructose/air biological fuel cell based on direct electron transfer, BIOSENSORS & BIOELECTRONICS 25 (2) pp. 326-331 ELSEVIER ADVANCED TECHNOLOGY
Milton R, Giroud F, Thumser A, Minteer S, Slade R (2014) Bilirubin oxidase bioelectrocatalytic cathodes: the impact of hydrogen peroxide., Chemical Communications 50 (1) pp. 94-96 Royal Society of Chemistry
Mediator-less, direct electro-catalytic reduction of oxygen to water by bilirubin oxidase (Myrothecium sp.) was obtained on anthracene-modified, multi-walled carbon nanotubes. H2O2 was found to significantly and irreversibly affect the electro-catalytic activity of bilirubin oxidase, whereas similar electrodes comprised of laccase (Trametes versicolor) were reversibly inhibited.
THUMSER AEA, WILTON DC (1994) CHARACTERIZATION OF BINDING AND STRUCTURAL-PROPERTIES OF RAT-LIVER FATTY-ACID-BINDING PROTEIN USING TRYPTOPHAN MUTANTS, BIOCHEMICAL JOURNAL 300 pp. 827-833 PORTLAND PRESS
Wu X, Zhao F, Rahunen N, Varcoe JR, Avignone-Rossa C, Thumser AE, Slade RC (2011) A role for microbial palladium nanoparticles in extracellular electron transfer., Angew Chem Int Ed Engl 50 (2) pp. 427-430
Storch J, Thumser AEA (2000) The fatty acid transport function of fatty acid-binding proteins, Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1486 (1) pp. 28-44 ELSEVIER SCIENCE BV
The intracellular fatty acid-binding proteins (FABPs) comprise a family of 14?15 kDa proteins which bind long-chain fatty acids. A role for FABPs in fatty acid transport has been hypothesized for several decades, and the accumulated indirect and correlative evidence is largely supportive of this proposed function. In recent years, a number of experimental approaches which more directly examine the transport function of FABPs have been taken. These include molecular level in vitro modeling of fatty acid transfer mechanisms, whole cell studies of fatty acid uptake and intracellular transfer following genetic manipulation of FABP type and amount, and an examination of cells and tissues from animals engineered to lack expression of specific FABPs. Collectively, data from these studies have provided strong support for defining the FABPs as fatty acid transport proteins. Further studies are necessary to elucidate the fundamental mechanisms by which cellular fatty acid trafficking is modulated by the FABPs.
Khodadadi I, Griffin BA, Thumser AEA (2008) Differential effects of long-chain fatty acids and clofibrate on gene expression profiles in cardiomyocytes., Arch Iran Med 11 (1) pp. 42-49 Academy of Medical Sciences of the I.R. Iran
The link between dietary fat and coronary heart disease has attracted much attention since the effect of long-chain fatty acids on gene transcription has been established. The aim of this study was to investigate the effects of long-chain fatty acids and clofibrate on mRNA levels of specific lipid metabolism-related genes and to determine their effects on global transcriptome levels in a cardiovascular cell-line.
Zhao F, Rahunen N, Varcoe J, Roberts A, Avignone-Rossa C, Thumser AEA, Slade RCT (2009) Factors affecting the performance of microbial fuel cells for sulfur pollutants removal, Biosensors and Bioelectronics 24 (7) pp. 1931-1936
The importance of active drug transport in determining chemical fate is becoming increasingly clear, with efflux transporters such as MDR1, MRP2 and BCRP recognised as key determinants of drug action. The impact have been shown to impact compound bioavailability through first-pass effects; determine target site drug concentrations through affecting drug distribution; and drive drug resistance through their up-regulation following chronic drug exposure. While the role of these transporters is well established, less is known about transporters such as MRP3 and MRP4, which act to move chemicals back into the systemic circulation rather than target them for elimination. In this thesis the hypothesis examined states, ?transport and metabolism processes are balanced to allow for efficient handling of both endogenous and xenobiotics substrates into the excreta and systemic circulation?.
To examine this hypothesis a portion of the molecular interaction network of active drug transporters, passive transport and drug metabolising enzymes that determines the biological fate of 17²-estradiol in the liver was reconstructed. The model was parameterised using experimentally-derived kinetic and abundance values where available, or biologically realistic estimates. The behaviour of the model was validated against in vitro measurement of estradiol fate in primary human hepatocytes. As such the model represents, to the best of our knowledge, the situation occurring in the liver.
Under steady-state conditions and physiologically relevant concentrations of 17²-estradiol robust network behaviour was predicted, with network flux predominantly via passive processes. To examine the role of dietary constituents on network behaviour, the impact of the flavonoid compounds hesperidin and naringin on MRP3 and MRP4-dependent transport was determined experimentally. Inhibitory constants were then applied to the in silico model of estradiol metabolism, predicting a complete loss of basolateral efflux by MRP4 and redirection of estradiol glucuronide transport via apical transporters.
In summary, we present a computational approach to examine the relative input of network components in determining drug fate, and the impact of food chemical interactions. Such computational approaches provide novel systems to examine the impact of genetic variation or transporter-specific inhibitors on drug fate and, hence, efficacy.