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Full-Text Articles in Social and Behavioral Sciences
Increased Probiotic Yogurt Or Resistant Starch Intake Does Not Affect Isoflavone Bioavailability In Subjects Consuming A High Soy Diet, Theresa A. Larkin, William E. Price, Lee B. Astheimer
Increased Probiotic Yogurt Or Resistant Starch Intake Does Not Affect Isoflavone Bioavailability In Subjects Consuming A High Soy Diet, Theresa A. Larkin, William E. Price, Lee B. Astheimer
Faculty of Science - Papers (Archive)
Objective: Probiotics and prebiotics that affect gut microflora balance and its associated enzymeactivity may contribute to interindividual variation in isoflavone absorption after soy intake, possiblyenhancing isoflavone bioavailability. This study examined the effects of the consumption ofbioactive yogurt (a probiotic) or resistant starch (a known prebiotic) in combination with high soyintake on soy isoflavone bioavailability.Methods: Using a crossover design, chronic soy consumption was compared with soy plusprobiotic yogurt or resistant starch in older male and postmenopausal females (n 31). Isoflavonebioavailability was assessed at the beginning and end of each 5-wk dietary period by samplingplasma and urine after a standardized soy meal.Results: …
Elucidation Of Double Bond Position In Unsaturated Lipids By Ozone Electrospray Ionization Mass Spectrometry (Ozesi-Ms), M. C. Thomas, Todd Mitchell, J. M. Deeley, D. G. Harman, R. C. Murphy, Stephen J. Blanksby
Elucidation Of Double Bond Position In Unsaturated Lipids By Ozone Electrospray Ionization Mass Spectrometry (Ozesi-Ms), M. C. Thomas, Todd Mitchell, J. M. Deeley, D. G. Harman, R. C. Murphy, Stephen J. Blanksby
Faculty of Science - Papers (Archive)
The position(s) of carbon-carbon double bonds within lipids can dramatically affect their structure and reactivity and thus has a direct bearing on biological function. Commonly employed mass spectrometric approaches to the characterization of complex lipids however, fail to localize sites of unsaturation within the molecular structure and thus cannot distinguish naturally occurring regioisomers. In a recent communication [Thomas, Mitchell, Blanksby in the Journal of the American Chemical Society, 2006, 128, 58-59] we have presented a new technique for the elucidation of double bond position in glycerophospholipids using ozone-induced fragmentation within the source of a conventional electrospray ionization mass spectrometer. Here …
Control Of Hiv Through The Inhibition Of Hiv-1 Integrase: A Medicinal Chemistry Perspective, Christopher Gordon, R. Griffith, Paul A. Keller
Control Of Hiv Through The Inhibition Of Hiv-1 Integrase: A Medicinal Chemistry Perspective, Christopher Gordon, R. Griffith, Paul A. Keller
Faculty of Science - Papers (Archive)
This article reviews the current status of classes of HIV-1 integrase enzyme inhibitors. These classes include peptide-based inhibitors, natural products, polyhydroxylated aromatics, diketo acids, naphthyridines, and sulfonated compounds including sulfonic acids. Discussions of structure activity relationships are presented and include the current overview of the structure-based model, suitable for the further design and development. To date, the advances in the medicinal chemistry of HIV-1 integrase inhibitors have relied mostly on ligand-based designs leading to most displaying similar binding interactions within the active site or at the dimer interface. This paves the way for single enzyme mutations rendering entire compound classes …
The Plasminogen-Binding Group A Streptococcal M Protein-Related Protein Prp Binds Plasminogen Via Arginine And Histidine Residues, Martina L. Sanderson-Smith, M. Dowton, Marie Ranson, Mark J. Walker
The Plasminogen-Binding Group A Streptococcal M Protein-Related Protein Prp Binds Plasminogen Via Arginine And Histidine Residues, Martina L. Sanderson-Smith, M. Dowton, Marie Ranson, Mark J. Walker
Faculty of Science - Papers (Archive)
The migration of the human pathogen Streptococcus pyogenes (group A streptococcus) from localized to deep tissue sites may result in severe invasive disease, and sequestration of the host zymogen plasminogen appears crucial for virulence. Here, we describe a novel plasminogen-binding M protein, the plasminogen-binding group A streptococcal M protein (PAM)-related protein (Prp). Prp is phylogenetically distinct from previously described plasminogen-binding M proteins of group A, C, and G streptococci. While competition experiments indicate that Prp binds plasminogen with a lower affinity than PAM (50% effective concentration = 0.34 µM), Prp nonetheless binds plasminogen with high affinity and at physiologically relevant …
A New Methodology For The Simulation Of Flexible Protein – Ligand Interactions, James A. Garner, John Deadman, David I. Rhodes, Renate Griffith, Paul A. Keller
A New Methodology For The Simulation Of Flexible Protein – Ligand Interactions, James A. Garner, John Deadman, David I. Rhodes, Renate Griffith, Paul A. Keller
Faculty of Science - Papers (Archive)
A methodology has been developed for the simulation of induced fit between a ligand and its target protein. It utilizes constrained molecular dynamics where atoms determined to be immobile from difference distance matrix studies are fixed. Application of this methodology to HIV-1 reverse transcriptase (RT) as the example target protein has demonstrated its robustness. Short simulation times are sufficient to achieve good refinement of docking poses resulting from exchange of structurally dissimilar inhibitors between crystal structures.
Detection Of Al(Iii) And Ga(Iii) Complexes With Morin By Electrospray Ionization Mass Spectrometry, John B. Bremner, Larry A. Hick, Jody Morgan, Saowanee Rattanaphani, Vichitr Rattanaphani, C Septhum
Detection Of Al(Iii) And Ga(Iii) Complexes With Morin By Electrospray Ionization Mass Spectrometry, John B. Bremner, Larry A. Hick, Jody Morgan, Saowanee Rattanaphani, Vichitr Rattanaphani, C Septhum
Faculty of Science - Papers (Archive)
The Al(III) and Ga(III) complexes formed by morin (M) in aqueous solution were investigated by means of electrospray ionization mass spectrometry (ESI-MS). In the full scan mass spectra, Al:M showed 1:2 and 2:3 stoichiometric ratios. When (S)-N-acetylserine methyl ester (Ser), as a partial mimic of the serine residue in silk, was added to Al:M and Ga:M complexes in aqueous solution, the mass spectra of Ser:Al:M showed 1:1:1 and 1:1:2 stoichiometric ratios. The patterns of the mass spectra of Ga:M and Ser:Ga:M complexes were similar to those for the corresponding Al(III) complexes. Calculated heats of formation of potential structures of the …
Stress-Induced Retrotranslocation Of Clusterin/Apoj Into The Cytosol, P Nizard, Suzanne Tetley, Y Le Drean, T Watrin, P Le Goff, Mark R. Wilson, Denis Michel
Stress-Induced Retrotranslocation Of Clusterin/Apoj Into The Cytosol, P Nizard, Suzanne Tetley, Y Le Drean, T Watrin, P Le Goff, Mark R. Wilson, Denis Michel
Faculty of Science - Papers (Archive)
Clusterin is a usually secreted glycoprotein with chaperone properties. Recently, it has been suggested that clusterin isoforms reside in the nuclear and cytosolic compartments of human cell types, where they can influence various cellular programs including DNA repair, transcription and apoptosis. Several mechanisms have been proposed to explain this atypical location, including alternative transcription initiation and alternative splicing. However none of these have been unequivocally established as occurring in live cells. Here we provide direct experimental evidence that in live intact cells, under certain stress conditions, clusterin can evade the secretion pathway and reach the cytosol. This was demonstrated using …
Syntheses Of Spiro[Cyclopropane-1,3'-Oxindole]-2-Carboxylic Acid And Cyclopropa[C]Quinoline-7b-Carboxylic Acid And Their Derivatives, Sarah Yong, Alison T. Ung, Stephen G. Pyne, Brian W. Skelton, Allan H. White
Syntheses Of Spiro[Cyclopropane-1,3'-Oxindole]-2-Carboxylic Acid And Cyclopropa[C]Quinoline-7b-Carboxylic Acid And Their Derivatives, Sarah Yong, Alison T. Ung, Stephen G. Pyne, Brian W. Skelton, Allan H. White
Faculty of Science - Papers (Archive)
The synthesis of spiro[cyclopropane-1,3′-oxindole]-2-carboxylic acid, including novel 3-(2- and 3-pyridyl)-substituted analogues and the novel cyclopropa[c]quinoline-7b-carboxylic acid and their ester and amide derivatives is described. These syntheses involve diastereoselective cyclopropanation reactions of methyl 2-(2-nitrophenyl)acrylate and (3E)-(pyridin-2-ylmethylene)- and (3E)-(pyridin-3-ylmethylene)-1,3-dihydro-2H-indol-2-one with ethyl (dimethyl sulfuranylidene) acetate (EDSA). The synthesis of methyl cyclopropa[c]quinoline-7b-carboxylate involves a regioselective reductive cyclization of a nitro-diester precursor. The relative stereochemistry of key compounds has been determined by single-crystal X-ray structural analysis.
Synthesis Of Benzo[C]Chromen-6-Ones Via Novel Cyclic Aryl-Pd(Ii)-Ester Enolate Intermediates, Stephen R. Taylor, Alison T. Ung, Stephen G. Pyne
Synthesis Of Benzo[C]Chromen-6-Ones Via Novel Cyclic Aryl-Pd(Ii)-Ester Enolate Intermediates, Stephen R. Taylor, Alison T. Ung, Stephen G. Pyne
Faculty of Science - Papers (Archive)
The examination of the palladium catalysed arylation reactions of mono-iodo derivatives of the phenyl and benzyl esters of benzoic acid, phenylacetic acid and dehydrocinnamic acid has resulted in the formation of benzo[c]chromen-6-ones, unexpected cinnamate and succinate products and diphenyl dimers. Many of these products can be rationalized as arising from novel cyclic ArPd(II)-enolate intermediates, formed by intramolecular C-H activation by ArPd(II).
Solution Structure Of Domains Iva And V Of The Tau Subunit Of Escherichia Coli Dna Polymerase Iii And Interaction With The Alpha Subunit, Xun-Cheng Su, Slobodan Jergic, Max A Keniry, Nicholas E. Dixon, Gottfried Otting
Solution Structure Of Domains Iva And V Of The Tau Subunit Of Escherichia Coli Dna Polymerase Iii And Interaction With The Alpha Subunit, Xun-Cheng Su, Slobodan Jergic, Max A Keniry, Nicholas E. Dixon, Gottfried Otting
Faculty of Science - Papers (Archive)
The solution structure of the C-terminal Domain V of the τ subunit of E. coli DNA polymerase III was determined by nuclear magnetic resonance (NMR) spectroscopy. The fold is unique to τ subunits. Amino acid sequence conservation is pronounced for hydrophobic residues that form the structural core of the protein, indicating that the fold is representative for τ subunits from a wide range of different bacteria. The interaction between the polymerase subunits τ and α was studied by NMR experiments where α was incubated with full-length C-terminal domain (τC16), and domains shortened at the C-terminus by 11 …
The Repressor Element 1-Silencing Transcription Factor Regulates Heart-Specific Gene Expression Using Multiple Chromatin-Modifying Complexes, Andrew J. Bingham, Lezanne Ooi, Lukasz Kozera, Edward White, Ian C. Wood
The Repressor Element 1-Silencing Transcription Factor Regulates Heart-Specific Gene Expression Using Multiple Chromatin-Modifying Complexes, Andrew J. Bingham, Lezanne Ooi, Lukasz Kozera, Edward White, Ian C. Wood
Faculty of Science - Papers (Archive)
Cardiac hypertrophy is associated with a dramatic change in the gene expression profile of cardiac myocytes. Many genes important during development of the fetal heart but repressed in the adult tissue are reexpressed, resulting in gross physiological changes that lead to arrhythmias, cardiac failure, and sudden death. One transcription factor thought to be important in repressing the expression of fetal genes in the adult heart is the transcriptional repressor REST (repressor element 1-silencing transcription factor). Although REST has been shown to repress several fetal cardiac genes and inhibition of REST function is sufficient to induce cardiac hypertrophy, the molecular mechanisms …
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
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
Faculty of Science - Papers (Archive)
No abstract provided.
Potential Roles Of Abundant Extracellular Chaperones In The Control Of Amyloid Formation And Toxicity, Mark R. Wilson, Justin J. Yerbury, Stephen Poon
Potential Roles Of Abundant Extracellular Chaperones In The Control Of Amyloid Formation And Toxicity, Mark R. Wilson, Justin J. Yerbury, Stephen Poon
Faculty of Science - Papers (Archive)
The in vivo formation of fibrillar proteinaceous deposits called amyloid is associated with more than 40 serious human diseases, collectively referred to as protein deposition diseases. In many cases the amyloid deposits are extracellular and are found associated with newly identified abundant extracellular chaperones (ECs). Evidence is presented suggesting an important regulatory role for ECs in amyloid formation and disposal in the body. A model is presented which proposes that, under normal conditions, ECs stabilize extracellular misfolded proteins by binding to them, and then guide them to specific cell receptors for uptake and subsequent degradation. Thus ECs and their receptors …
Air-Drying Of Banana: Influence Of Experimental Parameters, Slab Thickness, Banana Maturity And Harvesting Season, Minh-Hue Nguyen, William E. Price
Air-Drying Of Banana: Influence Of Experimental Parameters, Slab Thickness, Banana Maturity And Harvesting Season, Minh-Hue Nguyen, William E. Price
Faculty of Science - Papers (Archive)
Air-drying of banana slabs has been investigated and the influence of experimental parameters such as temperature, relative humidity and slab thickness has been studied. This was in part re-investigated because of inconsistencies in previous studies, particularly in relation to derived water diffusion coefficients. In addition, it is shown that harvest season and hence initial moisture content has a very marked influence on the drying kinetics. By contrast banana maturity (ripeness) has little influence on the kinetics despite there being significant differences in morphology and chemical composition between green and ripe bananas. The effect of these two variables on the drying …
The Importance Of Slime: Does Living In A Community Matrix Save Algal Cells From The Toxic Effects Of Copper?, Jacqueline Levy, Dianne F. Jolley, Jenny L. Stauber
The Importance Of Slime: Does Living In A Community Matrix Save Algal Cells From The Toxic Effects Of Copper?, Jacqueline Levy, Dianne F. Jolley, Jenny L. Stauber
Faculty of Science - Papers (Archive)
Microscopic algae are often used to assess the toxic effects of chemicals to the environment. They are good indicators of ecosystem health because they form the basis of the aquatic food chain and many algal species are sensitive to metals, like copper, at concentrations which occur naturally in the environment. Most toxicity tests with algae use planktonic species, that is, alga that live in the water as free-living species. To date, little research has been done on the toxicity of metals to attached algal species living in a community matrix known as biofilms, because of the difficulties in quantifying changes …
Mechanochemical Coupling In The Myosin Motor Domain. I. Insights From Equilibrium Active-Site Simulations, Haibo Yu, Liang Ma, Yang Yang, Qiang Cui
Mechanochemical Coupling In The Myosin Motor Domain. I. Insights From Equilibrium Active-Site Simulations, Haibo Yu, Liang Ma, Yang Yang, Qiang Cui
Faculty of Science - Papers (Archive)
Although the major structural transitions in molecular motors are often argued to couple to the binding of Adenosine triphosphate (ATP), the recovery stroke in the conventional myosin has been shown to be dependent on the hydrolysis of ATP. To obtain a clearer mechanistic picture for such ‘‘mechanochemical coupling’’ in myosin, equilibrium active-site simulations with explicit solvent have been carried out to probe the behavior of the motor domain as functions of the nucleotide chemical state and conformation of the converter/relay helix. In conjunction with previous studies of ATP hydrolysis with different active-site conformations and normal mode analysis of structural flexibility, …
Free Fatty Acids From The Crude Hexane Extract Of The Aerial Parts Of Heliotropium Indicum Linn. Growing In Phitsanulok, Thailand, Theeraphan Machan, Jurgen Korth, Boonsom Liawruangrath, Saisunee Liawruangrath, Apiwat Baramee, Stephen G. Pyne
Free Fatty Acids From The Crude Hexane Extract Of The Aerial Parts Of Heliotropium Indicum Linn. Growing In Phitsanulok, Thailand, Theeraphan Machan, Jurgen Korth, Boonsom Liawruangrath, Saisunee Liawruangrath, Apiwat Baramee, Stephen G. Pyne
Faculty of Science - Papers (Archive)
Sixteen free fatty acids from the crude hexane extract of the aerial parts of Heliotropium indicum Linn. growing in Phitsanulok, Thailand, have been identified after conversion to their methyl esters with boron trifluoride-methanol followed by quantification by GC-FID and identification by GC-MS analysis. They accounted for 95% of the chromatographable components, with 9,12-octadecadienoic acid, (39.7%), 9-octadecenoic acid (32.4%), hexadecanoic acid (14.2%) and octadecanoic acid (5.1%), as the major constituents. A small amount of 6,10,14-trimethyl-2-pentadecanone and 3,7,11,15-tetramethyl-2-hexadecen-1-ol as well as a homologous series of n-alkanes present at trace level and ranging from C25 to C31 was also found …
Sensitivity Of Marine Microalgae To Copper: The Effect Of Biotic Factors On Copper Adsorption And Toxicity, Jacqueline Levy, Jenny L. Stauber, Dianne F. Jolley
Sensitivity Of Marine Microalgae To Copper: The Effect Of Biotic Factors On Copper Adsorption And Toxicity, Jacqueline Levy, Jenny L. Stauber, Dianne F. Jolley
Faculty of Science - Papers (Archive)
Microalgae are sensitive indicators of environmental change and, as the basis of most freshwater and marine ecosystems, are widely used in the assessment of risk and development of environmental regulations for metals. However, interspecies differences in sensitivity to metals are not well understood. The relationship between metal-algal cell binding and copper sensitivity of marine microalgae was investigated using a series of 72-h growth-rate inhibition bioassays and short-term (1-h) uptake studies. A range of marine algae from different taxonomic groups were screened to determine whether copper adsorption to the cell membrane was influenced by biotic factors, such as the ultrastructure of …
Some Approaches To New Antibacterial Agents, John B. Bremner
Some Approaches To New Antibacterial Agents, John B. Bremner
Faculty of Science - Papers (Archive)
Bacteria use a number of resistance mechanisms to counter the antibacterial challenge, and one of these is the expression of transmembrane protein-based efflux pumps which can pump out antibacterials from within the cells, thus lowering the antibacterial concentration to nonlethal levels. For example, in S. aureus, the NorA pump can pump out the antibacterial alkaloid berberine and ciprofloxacin. One general strategy to reduce the health threat of resistant bacteria is to block a major bacterial resistance mechanism at the same time as interfering with another bacterial pathway or target site. New developments of this approach in the context of dual-action …
Aryl Nitro Reduction With Iron Powder Or Stannous Chloride Under Ultrasonic Irradiation, A. B. Gamble, James A. Garner, Christopher Gordon, S. M. J. O'Conner, Paul A. Keller
Aryl Nitro Reduction With Iron Powder Or Stannous Chloride Under Ultrasonic Irradiation, A. B. Gamble, James A. Garner, Christopher Gordon, S. M. J. O'Conner, Paul A. Keller
Faculty of Science - Papers (Archive)
The selective reduction of aryl nitro compounds in the presence of sensitive functionalities, including halide, carbonyl, nitrile and ester substituents under ultrasonic irradiation at 35 kHz is reported in yields of 39-98%. Iron powder proved superior to stannous chloride with high tolerance of sensitive functional groups and high yields of the desired aryl amines in relatively short reaction times. Simple experimental procedure and purification also make the iron reduction of aryl nitro compounds advantageous over other methods of reduction.
Anisotropic Atomic Motions In High-Resolution Protein Crystallography Molecular Dynamics Simulations, Conrad J. Burden, Aaron J. Oakley
Anisotropic Atomic Motions In High-Resolution Protein Crystallography Molecular Dynamics Simulations, Conrad J. Burden, Aaron J. Oakley
Faculty of Science - Papers (Archive)
Molecular dynamics (MD) simulations using empirical force fields are popular for the study of proteins. In this work, we compare anisotropic atomic fluctuations in nanosecond-timescale MD simulations with those observed in an ultra-high-resolution crystal structure of crambin. In order to make our comparisons, we have developed a compact graphical technique for assessing agreement between spatial atomic distributions determined by MD simulations and observed anisotropic temperature factors.
Crystallization And Diffraction Data Of 1h-3-Hydroxy-4-Oxoquinoline 2,4-Dioxygenase: A Cofactor-Free Oxygenase Of The Alpha/Beta-Hydrolase Family, Ruhu Qi, Susanne Fetzner, Aaron J. Oakley
Crystallization And Diffraction Data Of 1h-3-Hydroxy-4-Oxoquinoline 2,4-Dioxygenase: A Cofactor-Free Oxygenase Of The Alpha/Beta-Hydrolase Family, Ruhu Qi, Susanne Fetzner, Aaron J. Oakley
Faculty of Science - Papers (Archive)
1H-3-Hydroxy-4-oxoquinoline 2,4-dioxygenase (QDO) from Pseudomonas putida 33/1 catalyses the oxygenolysis of 1H-3-hydroxy-4-oxoquinoline to form N-formylanthranilic acid and carbon monoxide without the aid of cofactors. Both N-terminally His6-tagged and native QDO were overexpressed in Escherichia coli and purified by conventional chromatographic procedures. Untagged QDO, but not His6-tagged QDO, was crystallized by the vapour-diffusion method, giving hexagonal bipyramid crystals belonging to space group P6(1)22. Selenomethionine-containing native QDO was prepared and crystallized under identical conditions. The unit-cell parameters were a = b = 90.1, c = 168.6 A, alpha = beta = 90, gamma = 120 degrees. Using synchrotron radiation, these crystals diffract …
Effect Of Overlying Water Ph, Dissolved Oxygen, Salinity And Sediment Disturbances On Metal Release And Sequestration From Metal Contaminated Marine Sediments, Clare Atkinson, Dianne F. Jolley, Stuart L. Simpson
Effect Of Overlying Water Ph, Dissolved Oxygen, Salinity And Sediment Disturbances On Metal Release And Sequestration From Metal Contaminated Marine Sediments, Clare Atkinson, Dianne F. Jolley, Stuart L. Simpson
Faculty of Science - Papers (Archive)
Experiments were undertaken to examine the key variables affecting metal release and sequestration processes in marine sediments with metal concentrations in sediments reaching up to 86, 240, 700, and 3000mgkg1 (dry weight) for Cd, Cu, Pb and Zn, respectively. The metal release and sequestration rates were affected to a much greater extent by changes in overlying water pH (5.58.0) and sediment disturbance (by physical mixing) than by changes in dissolved oxygen concentration (38mgl1) or salinity (1545 practical salinity units). The physical disturbance of sediments was also found to release metals more rapidly than biological disturbance (bioturbation). The rate of oxidative …
The Pyrido[1,2-A]Azepine Stemona Alkaloids, Stephen G. Pyne, Alison T. Ung, Araya Jatisatienr, Pitchaya Mungkornasawakul
The Pyrido[1,2-A]Azepine Stemona Alkaloids, Stephen G. Pyne, Alison T. Ung, Araya Jatisatienr, Pitchaya Mungkornasawakul
Faculty of Science - Papers (Archive)
This paper reviews the isolation, structure elucidation, proposed biosynthesis and biological activities of the small, but increasing, number of pyrido[1,2-a]azepine Stemona alkaloids.
Using Calibration Approaches To Compensate For Remaining Matrix Effects In Quantitative Liquid Chromatography Electrospray Ionization Multistage Mass Spectrometric Analysis Of Phytoestrogens In Aqueous Environmental Samples, Jinguo Kang, Larry A. Hick, William E. Price
Using Calibration Approaches To Compensate For Remaining Matrix Effects In Quantitative Liquid Chromatography Electrospray Ionization Multistage Mass Spectrometric Analysis Of Phytoestrogens In Aqueous Environmental Samples, Jinguo Kang, Larry A. Hick, William E. Price
Faculty of Science - Papers (Archive)
Signal suppression is a common problem in quantitative LC-ESI-MSn analysis in environment samples, especially in highly loaded wastewater samples with highly complex matrix. Optimization of sample preparation and improvement of chromatographic separation are prerequisite to improve reproducibility and selectivity. Matrix components may be reduced if not eliminated by a series of sample preparation steps. However, extensive sample preparation can be time-consuming and risk the significant loss of some trace analytes. The best way to further compensate matrix effects is the use of internal standard for each analyte. However, in a multi-component analysis, finding appropriate internal standards for every analyte is …
A Fragmentation Study Of Isoflavones In Negative Electrospray Ionization By Msn Ion Trap Mass Spectrometry And Triple Quadrupole Mass Spectrometry, Jinguo Kang, Larry A. Hick, William E. Price
A Fragmentation Study Of Isoflavones In Negative Electrospray Ionization By Msn Ion Trap Mass Spectrometry And Triple Quadrupole Mass Spectrometry, Jinguo Kang, Larry A. Hick, William E. Price
Faculty of Science - Papers (Archive)
This study has elucidated the fragmentation pathway for deprotonated isoflavones in electrospray ionization using MSn ion trap mass spectrometry and triple quadrupole mass spectrometry. Genistein-d4 and daidzein-d3 were used as references for the clarification of fragment structures. To confirm the relationship between precursor and product ions, some fragments were traced from MS2 to MS5. The previous literature for the structurally related flavones and flavanones located the loss of ketene (C2H2O) to ring C, whereas the present fragmentation study for isoflavones has shown that the loss of ketene occurs elsewhere at ring A. In the further fragmentation of the [M-H-CH3]•- radical …
Mechanochemical Coupling In The Myosin Motor Domain. Ii. Analysis Of Critical Residues, Haibo Yu, Liang Ma, Yang Yang, Qiang Cui
Mechanochemical Coupling In The Myosin Motor Domain. Ii. Analysis Of Critical Residues, Haibo Yu, Liang Ma, Yang Yang, Qiang Cui
Faculty of Science - Papers (Archive)
An important challenge in the analysis of mechanochemical coupling in molecular motors is to identify residues that dictate the tight coupling between the chemical site and distant structural rearrangements. In this work, a systematic attempt is made to tackle this issue for the conventional myosin. By judiciously combining a range of computational techniques with different approximations and strength, which include targeted molecular dynamics, normal mode analysis, and statistical coupling analysis, we are able to identify a set of important residues and propose their relevant function during the recovery stroke of myosin. These analyses also allowed us to make connections with …
The Vibrational Spectra Of Protonated Water Clusters: A Benchmark For Self-Consistent-Charge Density-Functional Tight Binding, Haibo Yu, Qiang Cui
The Vibrational Spectra Of Protonated Water Clusters: A Benchmark For Self-Consistent-Charge Density-Functional Tight Binding, Haibo Yu, Qiang Cui
Faculty of Science - Papers (Archive)
Proton transfers are involved in many chemical processes in solution and in biological systems. Although water molecules have been known to transiently facilitate proton transfers, the possibility that water molecules may serve as the “storage site” for proton in biological systems has only been raised in recent years. To characterize the structural and possibly the dynamic nature of these protonated water clusters, it is important to use effective computational techniques to properly interpret experimental spectroscopic measurements of condensed phase systems. Bearing this goal in mind, we systematically benchmark the self-consistent-charge density-functional tight-binding �SCC-DFTB� method for the description of vibrational spectra …
The Unstructured C-Terminus Of The Tau Subunit Of Escherichia Coli Dna Polymerase Iii Holoenzyme Is The Site Of Interaction With The Alpha Subunit, Slobodan Jergic, Kiyoshi Ozawa, Neal K. Williams, Xun-Cheng Su, Daniel D. Scott, Samir M. Hamdan, Jeffrey A. Crowther, Gottfried Otting, Nicholas E. Dixon
The Unstructured C-Terminus Of The Tau Subunit Of Escherichia Coli Dna Polymerase Iii Holoenzyme Is The Site Of Interaction With The Alpha Subunit, Slobodan Jergic, Kiyoshi Ozawa, Neal K. Williams, Xun-Cheng Su, Daniel D. Scott, Samir M. Hamdan, Jeffrey A. Crowther, Gottfried Otting, Nicholas E. Dixon
Faculty of Science - Papers (Archive)
The τ subunit of Escherichia coli DNA polymerase III holoenzyme interacts with the α subunit through its C-terminal Domain V, τC16. We show that the extreme C-terminal region of τC16 constitutes the site of interaction with α. The τC16 domain, but not a derivative of it with a C-terminal deletion of seven residues (τC16Δ7), forms an isolable complex with α. Surface plasmon resonance measurements were used to determine the dissociation constant (KD) of the α−τC16 complex to be ∼260 pM. Competition with immobilized τC16 by …
Synthesis Of Novel 3'-Spirocyclic-Oxindole Derivatives And Assessment Of Their Cytostatic Activities, Sarah Yong, Alison T. Ung, Stephen G. Pyne, Brian W. Skelton, Allan H. White
Synthesis Of Novel 3'-Spirocyclic-Oxindole Derivatives And Assessment Of Their Cytostatic Activities, Sarah Yong, Alison T. Ung, Stephen G. Pyne, Brian W. Skelton, Allan H. White
Faculty of Science - Papers (Archive)
The synthesis of some novel 3′-spirocyclic-oxindole compounds, based on the spiro[indole-3,5′-isoxazolidin]-2(1H)-one, the 2′H-spiro[indole-3,6′-[1,3]oxazinane]-2,2′(1H)-dione and the 2′H-spiro[indoline-3,3′-pyrrolo[1,2-c][1,3′]oxazine]-1′,2(1H)-dione heterocyclic structures, is described. These compounds were prepared from methyl α-(2-nitrophenyl)acrylate via [1,3]-dipolar cycloaddition reactions with two acyclic nitrones and one cyclic nitrone followed by reduction of the cycloadducts and then treatment with triphosgene. Two of these compounds showed significant cytostatic activity on three cancer cell lines with GI50 values of 2.6–4.1 μM on the human breast cancer cell line, MCF-7.