Biochemistry, Biophysics, and Structural Biology Commons^™

Theobromine And Related Methylxanthines As Inhibitors Of Primary Amine Oxidase, Padraig Shanahan, Jeffrey O’Sullivan, Keith Tipton, Gemma Kinsella, Barry Ryan, Gary Henehan

Articles

Methylxanthines are the most widely consumed drugs in the world and evidence of their health benefits has been growing in recent years. Primary Amine Oxidase (PrAO) has been recognised as a therapeutic target for amelioration of inflammatory, vascular and neurodegenerative diseases. Previous work in our laboratories showed that caffeine inhibited Bovine PrAO with a Ki of 1.0mM using benzylamine as substrate.

This study aimed to extend our previous work and explore the possibility that related methylxanthines might influence PrAO activity. While paraxanthine, theophylline and 7-methylxanthine had little effect on PrAO, theobromine was a noncompetitive inhibitor with a Ki of 276±44µM. …

Isolation, Purification And Characterization Of A Novel Solvent Stable Lipase From Pseudomonas Reinekei, Barry Ryan, Priyanka Priyanka, Gemma K. Kinsella, Gary T. Henehan

Articles

The Pseudomonas sp. have been long recognized for their exogenous lipolytic activities yet the genus still contains a lot of unexplored strains. Due to the versatile metabolic machinery and their potential for adaptation to fluctuating environmental conditions Pseudomonas sp. are of great interest for biotechnological applications. In this study, a new extracellularly produced lipolytic enzyme from Pseudomonas sp. (P. reinekei) was purified and characterized. The production of lipase from P. reinekei (H1) was enhanced 10-fold by optimizing the nitrogen source. The 50 kDa H1 lipase was purified using negative and positive mode anion exchange chromatography. The purified lipase was active …

Multicomponent Analysis Using A Confocal Raman Microscope, Zhengyuan Tang, Sinead J. Barton, Thomas E. Ward, John P. Lowry, Michelle M. Doran, Hugh Byrne, Bryan M. Hennelly

Articles

Measuring the concentration of multiple chemical components in a low volume aqueous mixture by Raman spectroscopy has received significant interest in the literature. All of the contributions to date focus on the design of optical systems that facilitate the recording of spectra with high signal-to-noise ratio, by collecting as many Raman scattered photons as possible. In this study, the confocal Raman microscope set-up is investigated for multicomponent analysis. Partial Least Squares Regression is used to quantify physiologically relevant aqueous mixtures of glucose, lactic acid, and urea. The predicted error is 17.81 mg/dL for glucose, 10.6 mg/dL for lactic acid and …

Investigating The Role Of Gold Nanoparticle Shape And Size In Their Toxicities To Fungi, Kangze Liu, Zhonglei He, Hugh Byrne, James Curtin, Furong Tian Technological University Dublin

Articles

Gold nanoparticles (GNPs) are increasingly being used in a wide range of applications, and such they are being released in greater quantities into the environment. Consequently, the environmental effects of GNPs, especially toxicities to living organisms, have drawn great attention. However, their toxicological characteristics still remain unclear. Fungi, as the decomposers of the ecosystem, interact directly with the environment and critically control the overall health of the biosphere. Thus, their sensitivity to GNP toxicity is particularly important. The aim of this study was to evaluate the role of GNP shape and size in their toxicities to fungi, which could help …

Raman Spectral Analysis For Rapid Screening Of Dengue Infection, Tahir Mahmood, Haq Nawaz, A. Ditta, M.I. Majeed, M.A. Hanif, N. Rashid, H.N. Bhatti, H.F. Nargis, M. Saleem, Franck Bonnier, Hugh Byrne

Articles

Infection with the dengue virus is currently clinically detected according to different biomarkers in human blood plasma, commonly measured by enzyme linked immunosorbent assays, including non-structural proteins (Ns1), immunoglobulin M (IgM) and immunoglobulin G (IgG). However, there is little or no mutual correlation between the biomarkers, as demonstrated in this study by a comparison of their levels in samples from 17 patients. As an alternative, the label free, rapid screening technique, Raman spectroscopy has been used for the characterisation/diagnosis of healthy and dengue infected human blood plasma samples. In dengue positive samples, changes in specific Raman spectral bands associated with …

Clinical Applications Of Infrared And Raman Spectroscopy: State Of Play And Future Challenges, Matthew Baker, Hugh Byrne, John Chalmers, Peter Gardner, Royston Goodacre, Alex Henderson, Sergei Kazarian, Francis Martin, Julian Moger, Nick Stone, Josep Sule-Suso

Articles

Vibrational spectroscopies, based on Infrared absorption and/or Raman scattering provide a detailed fingerprint of a material, based on the chemical content. Diagnostic and prognostic tools based on these technologies have the potential to revolutionise our clinical systems leading to improved patient outcome, more efficient public services and significant economic savings. However, despite these strong drivers, there are many fundamental scientific and technological challenges which have limited the implementation of this technology in the clinical arena, although recent years have seen significant progress in addressing these challenges. This review examines (i) the state of the art of clinical applications of infrared …

Toxicological Assessment Of Nanomaterials: The Role Of In Vitro Raman Microspectroscopic Analysis, Esen Efeoglu, Marcus Maher, Alan Casey, Hugh Byrne

Articles

The acceleration of nanomaterials research has brought about increased demands for rapid analysis of their bioactivity, in a multi-parametric fashion, to minimise the gap between potential applications and knowledge of their toxicological properties. The potential of Raman microspectroscopy for the analysis of biological systems with the aid of multivariate analysis techniques has been demonstrated. In this study, an overview of recent efforts towards establishing a ‘label-free high content nanotoxicological assessment technique’ using Raman microspectroscopy is presented. The current state of the art for cellular toxicity assessment and the potential of Raman microspectroscopy are discussed, and the spectral markers of the …

Cold Atmospheric Plasma Induces Atp-Dependent Endocytosis Of Nanoparticles And Synergistic U373mg Cancer Cell Death, Zhonglei He, Kangze Liu, Eline Manaloto, Alan Casey, George P. Cribaro, Hugh Byrne, Furong Tian, Carlos Barcia, Gillian Conway, Patrick J. Cullen, James Curtin

Articles

Gold nanoparticles (AuNP) have potential as both diagnostic and therapeutic vehicles. However, selective targeting and uptake in cancer cells remains challenging. Cold atmospheric plasma (CAP) can be combined with AuNP to achieve synergistic anti-cancer cytotoxicity. To explore synergistic mechanisms, we demonstrate both rate of AuNP uptake and total amount accumulated in U373MG Glioblastoma multiforme (GBM) cells are signifcantly increased when exposed to 75kV CAP generated by dielectric barrier discharge. No signifcant changes in the physical parameters of AuNP were caused by CAP but active transport mechanisms were stimulated in cells. Unlike many other biological efects of CAP, long-lived reactive species …

In Vitro Label Free Screening Of Chemotherapeutic Drugs Using Raman Micro-Spectroscopy: Towards A New Paradigm Of Spectralomics., Zeineb Farhane, Haq Nawaz, Franck Bonnier, Hugh Byrne

Articles

This overview groups some of the recent studies highlighting the potential application of Raman micro-spectroscopy as an analytical technique in preclinical development to predict drug mechanism of action and in clinical application as a companion diagnostic and in personalised therapy due to its capacity to predict cellular resistance and therefore to optimise chemotherapeutic treatment efficacy.

Notably, the anthracyclines, Doxorubicin and Actinomycin D, elicit similar spectroscopic signatures of subcellular interaction characteristic of the mode of action of intercalation. Although Cisplatin and Vincristine show markedly different signatures, at low exposure doses, their signatures at higher doses show marked similarities to those elicited …

A Conceptual Framework For Understanding The Biogeochemistry Of Dry Riverbeds Through The Lens Of Soil Science, Maria Isabel Arce, Clara Mendoza, Maria Almagro, Nuria Catalan, Anna M. Romani, Eugenia Marti, R. Gomez, Susana Bernal, Arnaud Foulquier, Michael Mutz, Rafael Marce, Annamaria Zoppini, Giulia Gionchetta, Gabriele Weigelhofer, R. Del Campo, Christopher T. Robinson, Alan Gilmer, Martin Rulik, Obrador Biel, Oleksandra Shumilova, Sanja Zlatanovic, Shai Arnon, Petr Baldrian, Gabriel Andreas Singer, Thibault Datry, Nikolaos Th Skoulikidis, Britta Tietjen, Daniel Von Schiller

Articles

Intermittent rivers and ephemeral streams (IRES) encompass fluvial ecosystems that eventually stop flowing and run dry at some point in space and time. During the dry phase, channels of IRES consist mainly of dry riverbeds (DRBs), prevalent yet widely unexplored ecotones between dry and wet phases that can strongly influence the biogeochemistry of fluvial networks. DRBs are often overlooked because they do not strictly belong to either domain of soil or freshwater science. Due to this dual character of DRBs, we suggest that concepts and knowledge from soil science can be used to expand the understanding of IRES biogeochemistry. Based …

The Western Diet: A Smoking Gun For Chronic Obstructive Pulmonary Disease And Asthma?, Conor Kerley

Other resources

No abstract provided.

Measurement & Analysis Of The Temporal Discrimination Threshold Applied To Cervical Dystonia, Rebecca B. Beck, Eavan M. Mcgovern, John Butler, Dorina Birsanu, Brendan Quinlivan, Ines Beiser, Shrut Narasimham, Sean O'Riordan, Michael Hutchinson, Richard B. Reilly

Other resources

The temporal discrimination threshold (TDT) is the shortest time interval at which an observer can discriminate two sequential stimuli as being asynchronous (typically 30-50 ms). It has been shown to be abnormal (prolonged) in neurological disorders, including cervical dystonia, a phenotype of adult onset idiopathic isolated focal dystonia. The TDT is a quantitative measure of the ability to perceive rapid changes in the environment and is considered indicative of the behavior of the visual neurons in the superior colliculus, a key node in covert attentional orienting. This article sets out methods for measuring the TDT (including two hardware options and …

Synthesis, Characterisation And Dna Intercalation Studies Of Regioisomers Of Ruthenium (Ii) Polypyridyl Complexes, Laura Perdisatt, Samar Moqadasi, Luke O'Neill, Gary Hessman, Alessandra Ghion, Muhammad Qasim Mushtaq Warraich, Alan Casey, Christine O'Connor

Articles

Regioisomers of the functional group of the main ligand (L) on a series of [Ru(phen)2L]2+and [Ru(bpy)2L]2+ complexes, where phen is 1,10 phenanthroline and bpy is 2,2′-bipyridine, were synthesised to investigate the interaction with deoxyribonucleic acid (DNA) as potential therapeutics. UV–Vis binding titrations, thermal denaturation and circular dichroism were used to evaluate their interaction with DNA. The conclusions indicated the significance of the auxiliary ligand; especially 1,10-phenanthroline has on the binding constants (Kb). The systematic variation of auxiliary ligand(phen or bpy), and polypyridyl ligand (4-(1H-Imidazo[4,5-f][1,10]phenanthrolin-2-yl)benzonitrile (CPIP), 2-(4-formylphenyl)imidazo[4,5-f] [1,10] phenanthroline (FPIP), 2-(4-bromophenyl)imidazo[4,5-f][1,10]phenanthroline (BPIP) and 2-(4-nitrophenyl)imidazo[4,5-f] [1,10] phenanthroline (NPIP), split in terms of …

Raman Spectroscopic Analysis Of High Molecular Weight Proteins In Solution - Considerations For Sample Analysis And Data Pre-Processing, Drishya Rajan Parachalil, Brenda B. Brankin, Jennifer Mcintyre, Hugh Byrne

Articles

This study explores the potential of Raman spectroscopy, coupled with multivariate regression techniques and a protein separation technique (ion exchange chromatography), to quantitatively monitor diagnostically relevant changes in high molecular weight proteins in liquid plasma. Measurement protocols to detect the imbalances in plasma proteins as an indicator of various diseases using Raman spectroscopy are optimised, such that strategic clinical applications for early stage disease diagnostics can be evaluated. In a simulated plasma protein mixture, concentrations of two proteins of identified diagnostic potential (albumin and fibrinogen) were systematically varied within physiologically relevant ranges. Scattering from the poorly soluble fibrinogen fraction is …

Dietary Phytochemicals As Inhibitors Of Primary Amine Oxidase, Padraig Shanahan, Jeffrey O'Sullivan, Keith F. Tipton, Gemma Kinsella, Barry J. Ryan, Gary T. Henehan

Articles

Phytochemicals such as methylxanthines, catechins and polyphenols show health benefits in a range of diseases although their mechanism of action is not fully understood. Primary Amine Oxidase (PrAO) is widely recognised as a therapeutic drug target for the treatment of inflammatory, vascular and neurodegenerative diseases. Previous work in our laboratories showed that caffeine inhibited bovine PrAO activity with a Ki of 1.0mM. In the present study we examined a range of methylxanthines and catechins as inhibitors of bovine PrAO. The methylxanthines tested were caffeine, paraxanthine, theophylline, theobromine and 7-methylxanthine. Of these, only theobromine was an inhibitor with an IC50 of …

Industrial Grade 2d Molybdenum Disulphide (Mos2): An In-Vitro Exploration Of The Impact On Cellular Uptake, Cytotoxicity, And Inflammation, Caroline Moore, Hugh Byrne, Jonathan N. Coleman, Yuri Volkov, Jennifer Mcintyre

Articles

The recent surge in graphene research, since its liquid phase monolayer isolation and characterization in 2004, has led to advancements which are accelerating the exploration of alternative 2D materials such as molybdenum disulphide (MoS2), whose unique physico-chemical properties can be exploited in applications ranging from cutting edge electronic devices to nanomedicine. However, to assess any potential impact on human health and the environment, the need to understand the bio-interaction of MoS2 at a cellular and sub-cellular level is critical. Notably, it is important to assess such potential impacts of materials which are produced by large scale production techniques, rather than …

Isolation And Spectroscopic Characterization Of Zn(Ii), Cu(Ii), And Pd(Ii) Complexes Of 1,3,4-Thiadiazole-Derived Ligand, Dariusz Karcz, Arkadiusz Matwijczuk, Bozena Boron, Bernadette Creaven, Leszek Fiedor, Andrzej Niewiadomy, Mariusz Gagos

Articles

A series of complexes incorporating Zn(II), Cu(II), and Pd(II) ions, and 4-(5-heptyl-1,3,4-thiadiazol-2-yl)benzene-1,3-diol (L1) as model ligand, was synthesized in order to examine the nature of potential interactions between biologically active ligands, 1,3,4-thiadiazoles and metal ions with proven biological relevance. The structures of the compounds isolated were characterized using a number of spectroscopic methods including IR, Uv–vis, AAS, steady state and time-resolved fluorescence (TRF). The results obtained suggest that the L1-Zn(II) and L1-Pd(II) complexes consist of one molecule of L1 and one acetate ion acting as ligands, while the L1-Cu(II) complex adapts a 2:1 (L1: metal) stoichiometry. The coordination of L1 …

Avoiding Proteolysis During Protein Purification, Barry J. Ryan, Gary T. Henehan

Books/Book Chapters/ Proceedings

All cells contain proteases which hydrolyze the peptide bonds between amino acids in a protein backbone. Typically, proteases are prevented from nonspecific proteolysis by regulation and by their physical separation into different subcellular compartments; however, this segregation is not retained during cell lysis, which is the initial step in any protein isolation procedure. Prevention of proteolysis during protein purification often takes the form of a two-pronged approach; firstly inhibition of proteolysis in situ, followed by the early separation of the protease from the protein of interest via chromatographical purification. Protease inhibitors are routinely used to limit the effect of the …

Differential Precipitation And Solubilisation Of Proteins, Barry J. Ryan, Gemma K. Kinsella

Books/Book Chapters/ Proceedings

Differential protein precipitation is a rapid and economical step in protein purification and is based on exploiting the inherent physicochemical properties of the polypeptide. Precipitation of recombinant proteins, lysed from the host cell, is commonly used to concentrate the protein of choice before further polishing steps with more selective purification columns (e.g., His-Tag, Size Exclusion, etc.). Recombinant proteins can also precipitate naturally as inclusion bodies due to various influences during overexpression in the host cell. Although this phenomenon permits easier initial separation from native proteins, these inclusion bodies must carefully be differentially solubilized so as to reform functional, correctly folded …

Disrupted Superior Collicular Activity May Reveal Cervical Dystonia Disease Pathomechanisms, Eavan M. Mcgovern, Owen Killian, Shruti Narashimham, Brendan Quinlivan, John Butler, Rebecca Beck, Ines Beiser, Laura W. Williams, Ronan P. Killeen, Michael Farrell, Sean O'Riordan, Richard B. Reilly, Michael Hutchinson

Articles

Cervical dystonia is a common neurological movement disorder characterised by muscle contractions causing abnormal movements and postures affecting the head and neck. The neural networks underpinning this condition are incompletely understood. While animal models suggest a role for the superior colliculus in its pathophysiology, this link has yet to be established in humans. The present experiment was designed to test the hypothesis that disrupted superior collicular processing is evident in affected patients and in relatives harbouring a disease-specific endophenotype (abnormal temporal discrimination). The study participants were 16 cervical dystonia patients, 16 unaffected first-degree relatives with abnormal temporal discrimination, 16 unaffected …

Pseudomonas Aeruginosa And Its 4 Arsenal Of Proteases: Weapons 5 To Battle The Host, A.C.M. Galdino, M.H.B Branquinha, A.L.S. Santos, L. Viganor

Books/Book chapters

Pseudomonas aeruginosa is a ubiquitous and opportunistic human pathogen that 12 represents a critical problem to the clinician due to the increased number of 13 resistant strains isolated from hospital settings. In addition, there is a great 14 variety of pathologies associated with this versatile Gram-negative bacterium. 15 P. aeruginosa cells are able to produce an incredible arsenal of virulence factors, 16 especially secreted molecules that act singly or together to ensure the 17 establishment, maintenance, and persistence of a successful infection in 18 susceptible hosts. In this context, pseudomonal proteases roles are highlighted 19 due to their ability to …

Methods To Assess The Direct Interaction Of C. Jejuni With Mucins, Julie Ann Naughton, Marguerite Clyne, Gina Duggan, Billy Bourke

Books/Book chapters

Studies of the interaction of bacteria with mucus secreting cells can be complemented at a more mechanistic level by exploring the interaction of bacteria with purified mucins. Here we describe a far western blotting approach to show how C. jejuni proteins separated by SDS PAGE and transferred to a membrane or slot blotted directly onto a membrane can be probed biotinylated mucin. In addition we describe the use of novel mucin microarrays to assess bacterial interactions with mucins in a high throughput manner.

In Vitro Monitoring Of Time And Dose Dependent Cytotoxicity Of Aminated Nanoparticles Using Raman Spectroscopy, Esen Efeoglu, Alan Casey, Hugh Byrne

Articles

No abstract provided.

Spectroscopic Studies Of Anthracyclines: Structural Characterization And In Vitro Tracking, Zeineb Farhane, Hugh Byrne, Malgorzata Baranska

Articles

A broad spectroscopic characterization, using ultraviolet-visible (UV-vis) and Fourier transform infrared absorption as well as Raman scattering, of two commonly used anthracyclines antibiotics (DOX) daunorubicin (DNR), their epimers (EDOX, EDNR) and ten selected analogs is presented. The paper serves as a comprehensive spectral library of UV-vis, IR and Raman spectra of anthracyclines in the solid state and in solution. The particular advantage of Raman spectroscopy for the measurement and analysis of individual antibiotics is demonstrated. Raman spectroscopy can be used to monitor the in vitro uptake and distribution of the drug in cells, using both 488 nm and 785 nm …

A Comparison Of Catabolic Pathways Induced In Primary Macrophages By Pristine Single Walled Carbon Nanotubes And Pristine Graphene, Caroline More, Jennifer Mcintyre, Luke O'Neill, Hugh Byrne

Articles

Understanding the correlation between the physico-chemical properties of carbonaceous nanomaterials and how these properties impact on cells and subcelluar mechanisms is critical to their risk assessment and safe translation into newly engineered devices. Here the toxicity, uptake and catabolic response of primary human macrophages to pristine graphene (PG) and pristine single walled carbon nanotubes (pSWCNT) are explored, compared and contrasted. The nanomaterial toxicity was assessed using three complementary techniques (live-dead assay, real time impedance technique and confocal microscopic analysis), all of which indicated no signs of acute cytotoxicity in response to PG or pSWCNT. Transmission electron microscopy (TEM) demonstrated that …

Modification Of The In Vitro Uptake Mechanism And Anti-Oxidant Levels In Hacat Cells And Resultant Changes To Toxicity And Oxidative Stress Of G4 And G6 Poly (Amido Amine) Dendrimer Nanoparticles., Marcus Maher, Hugh Byrne

Articles

The mechanism of cellular uptake by endocytosis and subsequent oxidative stress has been identified as the paradigm for the toxic response of cationically surface charged nanoparticles. In an attempt to circumvent the process, the effect of increased cellular membrane permeability on the uptake mechanisms of poly (amidoamine) dendrimers generation 4 (G4) and 6 (G6) in vitro was investigated. Immortalised, non-cancerous human keratinocyte (HaCaT) cells were treated with DL-Buthionine-(S,R)-sulfoximine (BSO). Active uptake of the particles was monitored using fluorescence microscopy to identify and quantify endosomal activity and resultant oxidative stress, manifest as increased levels of reactive oxygen species, monitored using the …

Evaluation Of Cytotoxicity Profile And Intracellular Localisation Of Doxorubicin-Loaded Chitosan Nanoparticles, Gabriele Dadalt Souto, Zeineb Farhane, Esen Efeoglu, Alan Casey, Jennifer Mcintyre, Hugh Byrne

Articles

In the emerging field of nanomedicine, targeted delivery of nanoparticle encapsulated active pharmaceutical ingredients (API) is seen as a potential significant development, promising improved pharmacokinetics and reduced side effects. In this context, understanding the cellular uptake of the nanoparticles and subsequent subcellular distribution of the API is of critical importance. Doxorubicin (DOX) was encapsulated within chitosan nanoparticles to investigate its intracellular delivery in A549 cells in vitro. Unloaded (CS-TPP) and doxorubicin-loaded (DOX-CS-TPP) chitosan nanoparticles were characterised for size (473±41 nm), polydispersity index (0.3±0.2), zeta potential (34±4 mV), drug content (76±7 µM) and encapsulation efficiency (95±1%). The cytotoxic response to …

Spectral Pre And Post Processing For Infrared And Raman Spectroscopy Of Biological Tissues And Cells, Hugh Byrne, Peter Knief, Mark Keating, Franck Bonnier

Articles

Vibrational Spectroscopy, both infrared absorption and Raman spectroscopy, have attracted increasing attention for biomedical applications, from in vivo and ex vivo disease diagnostics and screening, to in vitro screening of therapeutics. There remain, however, many challenges related to the accuracy of analysis of physically and chemically inhomogeneous samples, across heterogeneous sample sets. Data preprocessing is required to deal with variations in instrumental responses and intrinsic spectral backgrounds and distortions in order to extract reliable spectral data. Data postprocessing is required to extract the most reliable information from the sample sets, based on often very subtle changes in spectra associated with …

Acellular Reactivity Of Polymeric Dendrimer Nanoparticles As An Indicator Of Oxidative Stress In Vitro, Marcus Maher, Humza Khalid, Hugh Byrne

Articles

The need for rapid and cost effective pre-screening protocols of the toxicological response of the vast array of emerging nanoparticle types is apparent and the emerging consensus on the paradigm of oxidative stress by generation of intracellular reactive oxygen species as a primary source of the toxic response suggests the development of acellular assays to screen for nanoparticle surface reactivity. This study explores the potential of the monoamine oxidase A (MAO-A) enzyme based assay with polymeric dendrimers as cofactors and serotonin as substrate, which generates H₂O₂, quantified by the conversion of the Carboxy-H₂DCFDA dye …

Non-Thermal Atmospheric Plasma Induces Ros-Independent Cell Death In U373mg Glioma Cells And Augments The Cytotoxicity Of Temozolomide, Gillian Conway, Alan Casey, Vladimir Milosavljevic, Yupeng Liu, Orla L. Howe, Patrick J. Cullen, James Curtin

Articles

Non-thermal atmospheric plasma (NTAP) is an ionised gas produced under high voltage that can generate short-lived chemically active species and induce a cytotoxic insult in cancer cells. Cell-specific resistance to NTAP-mediated cytotoxicity has been reported in the literature. The aim of this study was to determine whether resistance against NTAP could be overcome using the human glioma cell line U373MG.

Methods:

Non-thermal atmospheric plasma was generated using a Dielectric Barrier Device (DBD) system with a maximum voltage output of 120 kV at 50 Hz. The viability of U373MG GBM cells and HeLa cervical carcinoma cells was determined using morphology, flow …