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Articles 1 - 9 of 9

Full-Text Articles in Physical Sciences and Mathematics

Enhanced Molecular Chaperone Activity Of The Small Heat-Shock Protein Alphab-Cystallin Following Covalent Immobilization Onto A Solid-Phase Support, V Bellotti, Heath Ecroyd, J Carver, H J Griesser, B Thierry, J G Shapter, S S Griesser, S Giorgetti, M R Nussio, J A Gerrard, J Garvey Dec 2012

Enhanced Molecular Chaperone Activity Of The Small Heat-Shock Protein Alphab-Cystallin Following Covalent Immobilization Onto A Solid-Phase Support, V Bellotti, Heath Ecroyd, J Carver, H J Griesser, B Thierry, J G Shapter, S S Griesser, S Giorgetti, M R Nussio, J A Gerrard, J Garvey

Heath Ecroyd

The well-characterized small heat-shock protein, alphaB-crystallin, acts as a molecular chaperone by interacting with unfolding proteins to prevent their aggregation and precipitation. Structural perturbation (e.g., partial unfolding) enhances the in vitro chaperone activity of alphaB-crystallin. Proteins often undergo structural perturbations at the surface of a synthetic material, which may alter their biological activity. This study investigated the activity of alphaB-crystallin when covalently bound to a support surface; alphaB-crystallin was immobilized onto a range of solid material surfaces, and its characteristics and chaperone activity were assessed. Immobilization was achieved via a plasma-deposited thin polymeric interlayer containing aldehyde surface groups and reductive …


Mimicking Phosphorylation Of Alphab-Crystallin Affects Its Chaperone Activity, Heath W. Ecroyd, Sarah Meehan, J Horwitz, Andrew Aquilina, J L Benesch, C V Robinson, Cait Macphee, John Carver Jul 2012

Mimicking Phosphorylation Of Alphab-Crystallin Affects Its Chaperone Activity, Heath W. Ecroyd, Sarah Meehan, J Horwitz, Andrew Aquilina, J L Benesch, C V Robinson, Cait Macphee, John Carver

J. A. Aquilina

No abstract provided.


Activity And Molecular Dynamics Relationship Within The Family Of Human Cholinesterase, Judith Peters, Marie Trovaslet, Marcus Trapp, Florian Nachon, Flynn Hill, Etienne Royer, Frank Gabel, Lambert Van Eijck, Patrick Masson, Moeava Tehei Jan 2012

Activity And Molecular Dynamics Relationship Within The Family Of Human Cholinesterase, Judith Peters, Marie Trovaslet, Marcus Trapp, Florian Nachon, Flynn Hill, Etienne Royer, Frank Gabel, Lambert Van Eijck, Patrick Masson, Moeava Tehei

Faculty of Science - Papers (Archive)

The temperature dependence of the dynamics of recombinant human acetylcholinesterase (hAChE) and plasma human butyrylcholinesterase (hBChE) is examined using elastic incoherent neutron scattering. These two enzymes belong to the same family and present 50% amino acid sequence identity. However, significantly higher flexibility and catalytic activity of hAChE when compared to the ones of hBChE are measured. At the same time, the average height of the potential barrier to the motions is increased in the hBChE, e.g. more thermal energy is needed to cross it in the latter case, which might be the origin of the increase in activation energy and …


Selective Reduction Of Hydroperoxyeicosatetraenoic Acids To Their Hydroxy Derivatives By Apolipoprotein D: Implications For Lipid Antioxidant Activity And Alzheimer's Disease, Surabhi Bhatia, Bianca Knoch, Jenny Wong, Woojin Scott Kim, Paul Else, Aaron J. Oakley, Brett Garner Jan 2012

Selective Reduction Of Hydroperoxyeicosatetraenoic Acids To Their Hydroxy Derivatives By Apolipoprotein D: Implications For Lipid Antioxidant Activity And Alzheimer's Disease, Surabhi Bhatia, Bianca Knoch, Jenny Wong, Woojin Scott Kim, Paul Else, Aaron J. Oakley, Brett Garner

Faculty of Science - Papers (Archive)

ApoD (apolipoprotein D) is up-regulated in AD (Alzheimer's disease) and upon oxidative stress. ApoD inhibits brain lipid peroxidation in vivo, but the mechanism is unknown. Specific methionine residues may inhibit lipid peroxidation by reducing radical-propagating L-OOHs (lipid hydroperoxides) to non-reactive hydroxides via a reaction that generates MetSO (methionine sulfoxide). Since apoD has three conserved methionine residues (Met49, Met93 and Met157), we generated recombinant proteins with either one or all methionine residues replaced by alanine and assessed their capacity to reduce HpETEs (hydroperoxyeicosatetraenoic acids) to their HETE (hydroxyeicosatetraenoic acid) derivatives. ApoD, apoDM49-A and apoDM157-A all catalysed the reduction of HpETEs to …


Synthesis And Anti-Leukaemic Activity Of Pyrrolo[3,2,1-Hi]Indole-1,2- Diones, Pyrrolo[3,2,1-Ij]Quinoline-1,2-Diones And Other Polycyclic Isatin Derivatives, Lidia Matesic, Julie M. Locke, Kara Vine, Marie Ranson, John B. Bremner, Danielle Skropeta Jan 2012

Synthesis And Anti-Leukaemic Activity Of Pyrrolo[3,2,1-Hi]Indole-1,2- Diones, Pyrrolo[3,2,1-Ij]Quinoline-1,2-Diones And Other Polycyclic Isatin Derivatives, Lidia Matesic, Julie M. Locke, Kara Vine, Marie Ranson, John B. Bremner, Danielle Skropeta

Faculty of Science - Papers (Archive)

To further expand the structure–cytotoxic activity relationships of isatin derivatives and to reduce flexibility in substituent groups at nitrogen, 20 analogues incorporating a ring system between the N1 and C7 atoms of isatin were prepared using a variety of synthetic strategies. This yielded pyrroloindole-, pyrroloquinoline-, pyrroloacridine-, pyrrolophenanthridine- and benzopyrrolophenanthridine-based systems with embedded isatin moieties, the latter possessing a novel carbon skeleton. These compounds were subsequently assessed for their in vitro cytotoxicity against human U937 lymphoma cells, with the brominated pyrroloacridine dione 27 showing the most promising activity (IC50 3.01 μM) after 24 h.


The Relationship Between Particulate Pollution Levels In Australian Cities, Meteorology, And Landscape Fire Activity Detected From Modis Hotspots, Owen F. Price, Grant J. Williamson, Sarah B. Henderson, Fay Johnston, David M. J. S Bowman Jan 2012

The Relationship Between Particulate Pollution Levels In Australian Cities, Meteorology, And Landscape Fire Activity Detected From Modis Hotspots, Owen F. Price, Grant J. Williamson, Sarah B. Henderson, Fay Johnston, David M. J. S Bowman

Faculty of Science - Papers (Archive)

Generally, sigmoid curves are used to describe the growth of animals over their lifetime. However, because growth rates often differ over an animal's lifetime a single curve may not accurately capture the growth. Broken-stick models constrained to pass through a common point have been proposed to describe the different growth phases, but these are often unsatisfactory because essentially there are still two functions that describe the lifetime growth. To provide a single, converged model to age animals with disparate growth phases we developed a smoothly joining two-phase nonlinear function (SJ2P), tailored to provide a more accurate description of lifetime growth …


Phytochemical And Biological Activity Studies Of The Bhutanese Medicinal Plant Corydalis Crispa, Phurpa Wangchuk, Paul A. Keller, Stephen G. Pyne, Thanapat Sastraruji, Malai Taweechotipatr, Roonglawan Rattanajak, Aunchalee Tonsomboon, Sumalee Kamchonwongpaisan Jan 2012

Phytochemical And Biological Activity Studies Of The Bhutanese Medicinal Plant Corydalis Crispa, Phurpa Wangchuk, Paul A. Keller, Stephen G. Pyne, Thanapat Sastraruji, Malai Taweechotipatr, Roonglawan Rattanajak, Aunchalee Tonsomboon, Sumalee Kamchonwongpaisan

Faculty of Science - Papers (Archive)

The chemical constituents and biological activities of Corydalis crispa (Fumariaceae) were investigated for the first time. The phytochemical study resulted in the isolation of nine known isoquinoline alkaloids: protopine (1), 13-oxoprotopine (2), 13-oxocryptopine (3), stylopine (4), coreximine (5), rheagenine (6), ochrobirine (7), sibiricine (8) and bicuculline (9), with complete NMR data for 2 and 3 provided here for the first time. Crude extracts exhibitedsignificant anti-inflammatory (p < 0.01) activity against TNF-alpha production in LPS activated THP-1 cells. The acetylcholinesterase inhibitory activity of compounds 2, 4 and 7 and the antiplasmodial activity of compound 5 against P. falciparum strains TM4/8.2 and K1CB1 (multidrug resistant strain) are reported here for the first time. Stylopine (4) did not show antimalarial activity against the K1CB1 strain in contrast to a previous report. This study generated a scientific basis for the use of this plant in Bhutanese traditional medicine, either individually or in combination with other medicinal ingredients to treat a broad range of disorders. This study also identified compound 5 as potential new antimalarial lead compound.


Structural Insights Into The Dehydroascorbate Reductase Activity Of Human Omega-Class Glutathione Transferases, Huina Zhou, Joseph Brock, Dan Liu, Philip G. Board, Aaron J. Oakley Jan 2012

Structural Insights Into The Dehydroascorbate Reductase Activity Of Human Omega-Class Glutathione Transferases, Huina Zhou, Joseph Brock, Dan Liu, Philip G. Board, Aaron J. Oakley

Faculty of Science - Papers (Archive)

The reduction of dehydroascorbate (DHA) to ascorbic acid (AA) is a vital cellular function. The omega-class glutathione transferases (GSTs) catalyze several reductive reactions in cellular biochemistry, including DHA reduction. In humans, two isozymes (GSTO1-1 and GSTO2-2) with significant DHA reductase (DHAR) activity are found, sharing 64% sequence identity. While the activity of GSTO2-2 is higher, it is significantly more unstable in vitro. We report the first crystal structures of human GSTO2-2, stabilized through site-directed mutagenesis and determined at 1.9Å resolution in the presence and absence of glutathione (GSH). The structure of a human GSTO1-1 has been determined at 1.7Å resolution …


Net Superoxide Levels: Steeper Increase With Activity In Cooler Female And Hotter Male Lizards, Cissy Ballen, Mo Healey, Mark Wilson, Michael Tobler, Erik Wapstra, Mats Olsson Dec 2011

Net Superoxide Levels: Steeper Increase With Activity In Cooler Female And Hotter Male Lizards, Cissy Ballen, Mo Healey, Mark Wilson, Michael Tobler, Erik Wapstra, Mats Olsson

Mark R Wilson

"Ectotherms increase their body temperature in response to ambient heat, thereby elevating their metabolic rate. An often inferred consequence of this is an overall upregulation of gene expression and energetic expenditure, and a concomitant increased production of reactive oxygen species (e. g. superoxide) and, perhaps, a shortened lifespan. However, recent work shows that this may be a superficial interpretation. For example, sometimes a reduced temperature may in fact trigger up-regulation of gene expression. We studied temperature and associated activity effects in male and female Australian painted dragon lizards (Ctenophorus pictus) by allowing the lizards to bask for 4 h versus …