I grew up in the great city of Cape Town, South Africa, where I also attended the University of Cape Town to graduate eventually with a PhD from the Department of Medical Biochemistry. Subsequently, I spent some time working in the clinical laboratories, Wynberg Military Hospital; working on-call from Friday night until Monday morning was a good experience (e.g. diabetic patients keeping me the laboratory all night). Next stop was Southampton, where I worked on fatty acid-binding proteins with Prof David Wilton, which then led to a further post at Rutgers University, New Jersey, USA, with Prof Judy Storch. After eight years as post-doctoral research associate, I was offered the position of lecturer at the University of Surrey, first in the Division of Nutrition and now in the Department of Biochemistry & Physiology.A recent highlight has been a nomination for the University of Surrey Students Union “Best Lecturer” award and the Faculty of Health & Medical Sciences award of “Best Lecturer” in the Biological Sciences.
2016-current: Senior Teaching Fellow in Biochemistry
2012-2015: Senior Lecturer in Biochemistry, Faculty of Healthy and Medical Sciences, University of Surrey, United Kingdom
2000 - 2012: Lecturer in Biochemistry, Faculty of Healthy and Medical Sciences, University of Surrey, United Kingdom1997 - 2000: Post-Doctoral Research Associate; Dept. Nutritional Sciences, Cook College, Rutgers, The State University of New Jersey, U.S.A.1992 - 1996: Post-Doctoral Research Assistant; Dept. Biochemistry, University of Southampton, United Kingdom.1990 - 1991: Medical Corps (Clinical laboratories, Wynberg Military Hospital, South Africa)1990: Ph.D., Dept. Medical Biochemistry (University of Cape Town, South Africa). Title: The Glutathione S-Transferases: Inhibition, Activation, Binding and Kinetics.1984: B.Sc.(Med.)(Hons.), Medical Biochemistry (University of Cape Town).1983: B.Sc., with majors in Biochemistry and Microbiology (University of Cape Town).1980: Matriculation, Deutsche Schule Kapstadt (German school), Cape Town
Areas of specialism
Conductive cellulose-multiwalled carbonnanotube (MWCNT) matrix with a porous structure and good biocompatibility has been prepared using a room temperature ionicliquid (1-ethyl-3-methylimidazolium acetate) as solvent. Glucoseoxidase (GOx) was encapsulated in this matrix and thereby immobilized on a glassy carbon surface. The directelectrontransfer and electrocatalysis of the encapsulated GOx has been investigated using cyclic voltammetry and chronoamperometry. The GOx exhibited a pair of stable, well defined and nearly symmetric reversible redox peaks. The experimental results also demonstrate that the immobilized GOx retains its biocatalytic activity toward the oxidation of glucose and therefore can be employed in a glucose biosensor. The results show that the bioelectrode modified by the cellulose-MWCNT matrix has potential for use in biosensors and other bioelectronics devices.
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.
When developing meaningful curricula, institutions must engage with the desired disciplinary attributes of their graduates. Successfully employed in several areas, including psychology and chemistry, disciplinary literacies provide structure for the development of core competencies‐pursuing progressive education. To this end, we have sought to develop a comprehensive blueprint of a graduate biochemist, providing detailed insight into the development of skills in the context of disciplinary knowledge. The Biochemical Literacy Framework (BCLF) aspires to encourage innovative course design in both the biochemical field and beyond through stimulating discussion among individuals developing undergraduate biochemistry degree courses based on pedagogical best practice. Here, we examine the concept of biochemical literacy aiming to start answering the question: What must individuals do and know to approach and transform ideas in the context of the biochemical sciences? The BCLF began with the guidance published by relevant learned societies – including the Royal Society of Biology, the Biochemical Society, the American Society for Biochemistry and Molecular Biology and the Quality Assurance Agency, before considering relevant pedagogical literature. We propose that biochemical literacy is comprised of seven key skills: critical thinking, self‐management, communication, information literacy, visual literacy, practical skills and content knowledge. Together, these form a dynamic, highly interconnected and interrelated meta‐literacy supporting the use of evidence‐based, robust learning techniques. The BCLF is intended to form the foundation for discussion between colleagues, in addition to forming the groundwork for both pragmatic and exploratory future studies into facilitating and further defining biochemical literacy.
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 μW cm were observed for FAD-GDH/laccase biofuel cells. © 2013 the Owner Societies.
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 μA cm, and 46.5 ± 2.8 μW 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 μA cm, and 35.9 ± 1.3 μW 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.
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
In this case study, we discuss a Framework for Higher Education Qualifications (FHEQ) level 7 module, Developing as a Biochemist: Effectively Communicating Science in Modern Society, which forms a key part in the educational development of students in the final year of an MSci in Biochemistry at the University of Surrey. In this skills-based and student-centred module, students work to develop familiarity and competency across a broad range of communications platforms. A dynamic assessment approach enabled the provision of an active peer-feedback and peer-review process. The cyclical provision of feedback and review, coupled with the application of a greater level of feedback literacy, empowered students’ development of critical employability skills. We will discuss the background to this approach, the perceived effectiveness of the peer-review and peer-feedback process, from both teacher and learner perspectives, and will provide some considerations for implementing similar interventions in practice.
Purpose Concept maps have been described as a valuable tool for exploring curriculum knowledge. However, less attention has been given to the use of them to visualise contested and tacit knowledge, i.e. the values and perceptions of teachers that underpin their practice. This paper aims to explore the use of concept mapping to uncover academics’ views and help them articulate their perspectives within the framework provided by the concepts of pedagogic frailty and resilience in a collaborative environment. Design/methodology/approach Participants were a group of five colleagues within a Biochemical Science Department, working on the development of a new undergraduate curriculum. A qualitative single-case study was conducted to get some insights on how concept mapping might scaffold each step of the collaborative process. They answered the online questionnaire; their answers were “translated” into an initial expert-constructed concept map, which was offered as a starting point to articulate their views during a group session, resulting in a consensus map. Findings Engaging with the questionnaire was useful for providing the participants with an example of an “excellent” map, sensitising them to the core concepts and the possible links between them, without imposing a high level of cognitive load. This fostered dialogue of complex ideas, introducing the potential benefits of consensus maps in team-based projects. Originality/value An online questionnaire may facilitate the application of the pedagogic frailty model for academic development by scaling up the mapping process. The map-mediated facilitation of dialogue within teams of academics may facilitate faculty development by making explicit the underpinning values held by team members.
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.
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.
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.
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.