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- Dissolved organic matter (2)
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Articles 1 - 30 of 36
Full-Text Articles in Life Sciences
Metals And Metal Complexes In Diseases With A Focus On Covid-19: Facts And Opinions, Agnieszka Ścibior, Manuel Aureliano, Alvin A. Holder, Juan Llopis
Metals And Metal Complexes In Diseases With A Focus On Covid-19: Facts And Opinions, Agnieszka Ścibior, Manuel Aureliano, Alvin A. Holder, Juan Llopis
Chemistry & Biochemistry Faculty Publications
In the present Special Issue on “Metals and Metal Complexes in Diseases with a Focus on COVID-19: Facts and Opinions”, an attempt has been made to include reports updating our knowledge of elements considered to be potential candidates for therapeutic applications and certain metal-containing species, which are extensively being examined towards their potential biomedical use due to their specific physicochemical properties. The Special Issue compiles data on the role of metals in COVID-19 and focuses on other illnesses and biological processes that affect metal metabolism. It consists of eight manuscripts, including five review articles and three original research papers (Figure …
Natural Phaeosphaeride A Derivatives Overcome Drug Resistance Of Tumor Cells And Modulate Signaling Pathways, Victoria Abzianidze, Natalia Moiseeva, Diana Suponina, Sofya Zakharenkova, Nadezhda Rogovskaya, Lidia Laletina, Alvin A. Holder, Denis Krivorotov, Alexander Bogachenkov, Alexander Garabadzhiu, Anton Ukolov, Vyacheslav Kosorukov
Natural Phaeosphaeride A Derivatives Overcome Drug Resistance Of Tumor Cells And Modulate Signaling Pathways, Victoria Abzianidze, Natalia Moiseeva, Diana Suponina, Sofya Zakharenkova, Nadezhda Rogovskaya, Lidia Laletina, Alvin A. Holder, Denis Krivorotov, Alexander Bogachenkov, Alexander Garabadzhiu, Anton Ukolov, Vyacheslav Kosorukov
Chemistry & Biochemistry Faculty Publications
n the present study, natural phaeosphaeride A (PPA) derivatives are synthesized. Anti-tumor studies are carried out on the PC3, K562, HCT-116, THP-1, MCF-7, A549, NCI-H929, Jurkat, and RPMI8226 tumor cell lines, and on the human embryonic kidney (HEK293) cell line. All the compounds synthesized turned out to have better efficacy than PPA towards the tumor cell lines listed. Among them, three compounds exhibited an ability to overcome the drug resistance of tumor cells associated with the overexpression of the P-glycoprotein by modulating the work of this transporter. Luminex xMAP technology was used to assess the effect of five synthesized compounds …
Type-B Energetic Processes And Their Associated Scientific Implications, James Weifu Lee
Type-B Energetic Processes And Their Associated Scientific Implications, James Weifu Lee
Chemistry & Biochemistry Faculty Publications
Recently, our work has identified two thermodynamically distinct types (A and B) of energetic processes naturally occurring on Earth. Type-A energy processes such as the classical heat engines, ATP hydrolysis, and many of the known chemical, electrical, and mechanical processes apparently follow well the second law of thermodynamics; Type-B energy processes, for example, the newly discovered thermotropic function that isothermally utilizes environmental heat energy to do useful work in driving ATP synthesis, follow the first law of thermodynamics (conservation of mass and energy) but do not have to be constrained by the second law, owing to its special asymmetric functions. …
Microbial Labilization And Diversification Of Pyrogenic Dissolved Organic Matter, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher
Microbial Labilization And Diversification Of Pyrogenic Dissolved Organic Matter, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher
Chemistry & Biochemistry Faculty Publications
With the increased occurrence of wildfires around the world, interest in the chemistry of pyrogenic organic matter (pyOM) and its fate in the environment has increased. Upon leaching from soils by rain events, significant amounts of dissolved pyOM (pyDOM) enter the aquatic environment and interact with microbial communities that are essential for cycling organic matter within the different biogeochemical cycles. To evaluate the biodegradability of pyDOM, aqueous extracts of laboratory-produced biochars were incubated with soil microbes, and the molecular changes to the composition of pyDOM were probed using ultrahigh-resolution mass spectrometry (Fourier transform–ion cyclotron resonance–mass spectrometry). Given that solar irradiation …
Methylation Of The D2 Dopamine Receptor Affects Binding With The Human Regulatory Proteins Par-4 And Calmodulin, Alexander Bowitch, Ansuman Sahoo, Andrea M. Clark, Christiana Ntangka, Krishna K. Raut, Paul Gollnick, Michael C. Yu, Steven M. Pascal, Sarah E. Walker, Denise M. Ferkey
Methylation Of The D2 Dopamine Receptor Affects Binding With The Human Regulatory Proteins Par-4 And Calmodulin, Alexander Bowitch, Ansuman Sahoo, Andrea M. Clark, Christiana Ntangka, Krishna K. Raut, Paul Gollnick, Michael C. Yu, Steven M. Pascal, Sarah E. Walker, Denise M. Ferkey
Chemistry & Biochemistry Faculty Publications
No abstract provided.
Structual Analysis Of The Cl-Par-4 Tumor Suppressor As A Function Of Ionic Environment, Krishna K. Raut, Komala Ponniah, Steven M. Pascal
Structual Analysis Of The Cl-Par-4 Tumor Suppressor As A Function Of Ionic Environment, Krishna K. Raut, Komala Ponniah, Steven M. Pascal
Chemistry & Biochemistry Faculty Publications
Prostate apoptosis response-4 (Par-4) is a proapoptotic tumor suppressor protein that has been linked to a large number of cancers. This 38 kilodalton (kDa) protein has been shown to be predominantly intrinsically disordered in vitro. In vivo, Par-4 is cleaved by caspase-3 at Asp-131 to generate the 25 kDa functionally active cleaved Par-4 protein (cl-Par-4) that inhibits NF-κB-mediated cell survival pathways and causes selective apoptosis in tumor cells. Here, we have employed circular dichroism (CD) spectroscopy and dynamic light scattering (DLS) to assess the effects of various monovalent and divalent salts upon the conformation of cl-Par-4 in vitro. We have …
Protonic Capacitor: Elucidating The Biological Significance Of Mitochondrial Cristae Formation, James Weifu Lee
Protonic Capacitor: Elucidating The Biological Significance Of Mitochondrial Cristae Formation, James Weifu Lee
Chemistry & Biochemistry Faculty Publications
For decades, it was not entirely clear why mitochondria develop cristae? The work employing the transmembrane-electrostatic proton localization theory reported here has now provided a clear answer to this fundamental question. Surprisingly, the transmembrane-electrostatically localized proton concentration at a curved mitochondrial crista tip can be significantly higher than that at the relatively flat membrane plane regions where the proton-pumping respiratory supercomplexes are situated. The biological significance for mitochondrial cristae has now, for the first time, been elucidated at a protonic bioenergetics level: 1) The formation of cristae creates more mitochondrial inner membrane surface area and thus more protonic capacitance for …
Size-Dependent Inhibitory Effects Of Antibiotic Nanocarriers On Filamentation Of E. Coli, Preeyaporn Songkiatisak, Feng Ding, Pavan Kumar Cherukuri, Xiao-Hong Nancy Xu
Size-Dependent Inhibitory Effects Of Antibiotic Nanocarriers On Filamentation Of E. Coli, Preeyaporn Songkiatisak, Feng Ding, Pavan Kumar Cherukuri, Xiao-Hong Nancy Xu
Chemistry & Biochemistry Faculty Publications
Multidrug membrane transporters exist in both prokaryotic and eukaryotic cells and cause multidrug resistance (MDR), which results in an urgent need for new and more effective therapeutic agents. In this study, we used three different sized antibiotic nanocarriers to study their mode of action and their size-dependent inhibitory effects against Escherichia coli (E. coli). Antibiotic nanocarriers (AgMUNH–Oflx NPs) with 8.6 × 102, 9.4 × 103 and 6.5 × 105 Oflx molecules per nanoparticle (NP) were prepared by functionalizing Ag NPs (2.4 ± 0.7, 13.0 ± 3.1 and 92.6 ± 4.4 nm) with a monolayer …
A Halogen Bonding Perspective On Iodothyronine Deiodinase Activity, Eric S. Marsan, Craig A. Bayse
A Halogen Bonding Perspective On Iodothyronine Deiodinase Activity, Eric S. Marsan, Craig A. Bayse
Chemistry & Biochemistry Faculty Publications
Iodothyronine deiodinases (Dios) are involved in the regioselective removal of iodine from thyroid hormones (THs). Deiodination is essential to maintain TH homeostasis, and disruption can have detrimental effects. Halogen bonding (XB) to the selenium of the selenocysteine (Sec) residue in the Dio active site has been proposed to contribute to the mechanism for iodine removal. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are known disruptors of various pathways of the endocrine system. Experimental evidence shows PBDEs and their hydroxylated metabolites (OH-BDEs) can inhibit Dio, while data regarding PCB inhibition are limited. These xenobiotics could inhibit Dio activity by competitively …
Antibiotic Drug Nanocarriers For Probing Of Multidrug Abc Membrane Transporter Of Bacillus Subtilis, Pavan Kumar Cherukuri, Preeyaporn Songkiatisak, Feng Ding, Jeam-Michel Jault, Xiao-Hong Nancy Xu
Antibiotic Drug Nanocarriers For Probing Of Multidrug Abc Membrane Transporter Of Bacillus Subtilis, Pavan Kumar Cherukuri, Preeyaporn Songkiatisak, Feng Ding, Jeam-Michel Jault, Xiao-Hong Nancy Xu
Chemistry & Biochemistry Faculty Publications
Multidrug membrane transporters can extrude a wide range of substrates, which cause multidrug resistance and ineffective treatment of diseases. In this study, we used three different sized antibiotic drug nanocarriers to study their size-dependent inhibitory effects against Bacillus subtilis. We functionalized 2.4 ± 0.7, 13.0 ± 3.1, and 92.6 ± 4.4 nm silver nanoparticles (Ag NPs) with a monolayer of 11-amino-1-undecanethiol and covalently linked them with antibiotics (ofloxacin, Oflx). The labeling ratios of antibiotics with NPs are 8.6 × 102, 9.4 × 103, and 6.5 × 105 Oflx molecules per NP, respectively. We designed …
Isothermal Environmental Heat Energy Utilization By Transmembrane Electrostatically Localized Protons At The Liquid-Membrane Interface, James Weifu Lee
Isothermal Environmental Heat Energy Utilization By Transmembrane Electrostatically Localized Protons At The Liquid-Membrane Interface, James Weifu Lee
Chemistry & Biochemistry Faculty Publications
This study employing the latest theory on transmembrane electrostatic proton localization has now, for the first time, consistently elucidated a decades-longstanding bioenergetic conundrum in alkalophilic bacteria and more importantly discovered an entirely new feature: isothermal environmental heat utilization by electrostatically localized protons at the liquid-membrane interface. It was surprisingly revealed that the protonic motive force (equivalent to Gibbs free energy) from the isothermal environmental heat energy utilization through the electrostatically localized protons is not constrained by the overall energetics of the redox-driven proton pump system because of the following: (a) the transmembrane electrostatically localized protons are not free to move …
How Oxygen Availability Affects The Antimicrobial Efficacy Of Host Defense Peptides: Lessons Learned From Studying The Copper-Binding Peptides Piscidins 1 And 3, Adenrele Oludiran, David S. Courson, Malia D. Stuart, Anwar R. Radwan, John C. Putsma, Myriam L. Cotten, Erin B. Purcell
How Oxygen Availability Affects The Antimicrobial Efficacy Of Host Defense Peptides: Lessons Learned From Studying The Copper-Binding Peptides Piscidins 1 And 3, Adenrele Oludiran, David S. Courson, Malia D. Stuart, Anwar R. Radwan, John C. Putsma, Myriam L. Cotten, Erin B. Purcell
Chemistry & Biochemistry Faculty Publications
The development of new therapeutic options against Clostridioides difficile (C. difficile) infection is a critical public health concern, as the causative bacterium is highly resistant to multiple classes of antibiotics. Antimicrobial host-defense peptides (HDPs) are highly effective at simultaneously modulating the immune system function and directly killing bacteria through membrane disruption and oxidative damage. The copper-binding HDPs piscidin 1 and piscidin 3 have previously shown potent antimicrobial activity against a number of Gram-negative and Gram-positive bacterial species but have never been investigated in an anaerobic environment. Synergy between piscidins and metal ions increases bacterial killing aerobically. Here, we …
Molecular Level Comparison Of Water Extractives Of Maple And Oak With Negative And Positive Ion Esi Ft-Icr Mass Spectrometry, Zhongqi He, Rachel L. Sleighter, Patrick G. Hatcher, Shasha Liu, Fengchang Wu, Haixuan Zou, O. Modesto Olanya
Molecular Level Comparison Of Water Extractives Of Maple And Oak With Negative And Positive Ion Esi Ft-Icr Mass Spectrometry, Zhongqi He, Rachel L. Sleighter, Patrick G. Hatcher, Shasha Liu, Fengchang Wu, Haixuan Zou, O. Modesto Olanya
Chemistry & Biochemistry Faculty Publications
Soluble extractives in wood function to protect living trees from destructive agents and also contribute to wood color and fragrance. Some extractive components have biological activities with medical applications. They also play important roles in wood processing and related applications. To increase the knowledge of wood chemistry, maple and oak were extracted by water. Ultraviolet/visible (UV/vis) spectroscopy indicated the presence of a phenolic compound, resorcinol, in maple extractives having higher molecular mass and more aromatic components than oak extractives. Negative and positive electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS) identified thousands of formulas in the two …
Condensation And Polymerization Explain The Humification Of Lignin Into Aliphatic And Aromatic Structures In Soil, Patrick G. Hatcher, Hongmei Chen, Seyyedhadi Khatami, Derek C. Waggoner
Condensation And Polymerization Explain The Humification Of Lignin Into Aliphatic And Aromatic Structures In Soil, Patrick G. Hatcher, Hongmei Chen, Seyyedhadi Khatami, Derek C. Waggoner
Chemistry & Biochemistry Faculty Publications
Soil organic matter (SOM) constitutes a global reservoir of carbon that is more than twice that of either atmospheric carbon or aquatic carbon; however, the manner in which it forms from degraded plant biomass is poorly understood. Some have recently questioned whether plant biomass is involved directly in SOM formation and suggest that it is microbial carbon that constitutes the main source of stable SOM. Such a view implies that above and below ground plant biomass is rapidly decomposed and mineralized. This view contrasts significantly with traditional ones that involve the transformation of plant biomass to recalcitrant humic materials fueled …
Ph-Induced Folding Of The Caspase-Cleaved Par-4 Tumor Suppressor: Evidence Of Structure Outside Of The Coiled Coil Domain, Andrea M. Clark, Komala Ponniah, Meghan S. Warden, Emily M. Raitt, Andrea C. Yawn, Stephen M. Pascal
Ph-Induced Folding Of The Caspase-Cleaved Par-4 Tumor Suppressor: Evidence Of Structure Outside Of The Coiled Coil Domain, Andrea M. Clark, Komala Ponniah, Meghan S. Warden, Emily M. Raitt, Andrea C. Yawn, Stephen M. Pascal
Chemistry & Biochemistry Faculty Publications
Prostate apoptosis response-4 (Par-4) is a 38 kDa largely intrinsically disordered tumor suppressor protein that functions in cancer cell apoptosis. Par-4 down-regulation is often observed in cancer while up-regulation is characteristic of neurodegenerative conditions such as Alzheimer’s disease. Cleavage of Par-4 by caspase-3 activates tumor suppression via formation of an approximately 25 kDa fragment (cl-Par-4) that enters the nucleus and inhibits Bcl-2 and NF-ƙB, which function in pro-survival pathways. Here, we have investigated the structure of cl-Par-4 using biophysical techniques including circular dichroism (CD) spectroscopy, dynamic light scattering (DLS), and intrinsic tyrosine fluorescence. The results demonstrate pH-dependent folding of cl-Par-4, …
Synthesis And Biological Evaluation Of Phaeosphaeride A Derivatives As Antitumor Agents, Victoria Abzianidze, Petr Beltyukov, Sofya Zakharenkova, Natalia Moiseeva, Jennifer Mejia, Alvin Holder, Yuri Trishin, Alexander Berestetskiy, Victor Kuznetsov
Synthesis And Biological Evaluation Of Phaeosphaeride A Derivatives As Antitumor Agents, Victoria Abzianidze, Petr Beltyukov, Sofya Zakharenkova, Natalia Moiseeva, Jennifer Mejia, Alvin Holder, Yuri Trishin, Alexander Berestetskiy, Victor Kuznetsov
Chemistry & Biochemistry Faculty Publications
New derivatives of phaeosphaeride A (PPA) were synthesized and characterized. Anti-tumor activity studies were carried out on the HCT-116, PC3, MCF-7, A549, К562, NCI-Н929, Jurkat, THP-1, RPMI8228 tumor cell lines, and on the HEF cell line. All of the compounds synthesized were found to have better efficacy than PPA towards the tumor cell lines mentioned. Compound 6 was potent against six cancer cell lines, HCT-116, PC-3, K562, NCI-H929, Jurkat, and RPMI8226, showing a 47, 13.5, 16, 4, 1.5, and 7-fold increase in anticancer activity comparative to those of etoposide, respectively. Compound 1 possessed selectivity toward the NCI-H929 cell line (IC …
Size-Dependent Inhibitory Effects Of Antibiotic Drug Nanocarriers Against Pseudomonas Aeruginosa, Feng Ding, Preeyaporn Songkiatisak, Pavan Kumar Cherukuri, Tao Huang, Xiao-Hong Nancy Xu
Size-Dependent Inhibitory Effects Of Antibiotic Drug Nanocarriers Against Pseudomonas Aeruginosa, Feng Ding, Preeyaporn Songkiatisak, Pavan Kumar Cherukuri, Tao Huang, Xiao-Hong Nancy Xu
Chemistry & Biochemistry Faculty Publications
Multidrug membrane transporters (efflux pumps) are responsible for multidrug resistance (MDR) and the low efficacy of therapeutic drugs. Noble metal nanoparticles (NPs) possess a high surface-area-to-volume ratio and size-dependent plasmonic optical properties, enabling them to serve both as imaging probes to study sized-dependent MDR and as potential drug carriers to circumvent MDR and enhance therapeutic efficacy. To this end, in this study, we synthesized three different sizes of silver nanoparticles (Ag NPs), 2.4 ± 0.7, 13.0 ± 3.1, and 92.6 ± 4.4 nm, functionalized their surface with a monolayer of 11-amino-1-undecanethiol (AUT), and covalently conjugated them with antibiotics (ofloxacin, Oflx) …
Molecular Geometries And Other Properties Of H2o⋯Agi And H3n⋯Agi As Characterised By Rotational Spectroscopy And Ab Initio Calculations, Chris Medcraft, Eva Gougoula, Dror M. Bittner, John C. Mullaney, Susana Blanco, David P. Tew, Nicholas R. Walker, Anthony C. Legon
Molecular Geometries And Other Properties Of H2o⋯Agi And H3n⋯Agi As Characterised By Rotational Spectroscopy And Ab Initio Calculations, Chris Medcraft, Eva Gougoula, Dror M. Bittner, John C. Mullaney, Susana Blanco, David P. Tew, Nicholas R. Walker, Anthony C. Legon
Chemistry & Biochemistry Faculty Publications
The rotational spectra of H3N⋯AgI and H2O⋯AgI have been recorded between 6.5 and 18.5 GHz by chirped-pulse Fourier-transform microwave spectroscopy. The complexes were generated through laser vaporisation of a solid target of silver or silver iodide in the presence of an argon gas pulse containing a low concentration of the Lewis base. The gaseous sample subsequently undergoes supersonic expansion which results in cooling of rotational and vibrational motions such that weakly bound complexes can form within the expanding gas jet. Spectroscopic parameters have been determined for eight isotopologues of H3N⋯AgI and six isotopologues of …
Enhancement Of The Physicochemical Properties Of Pt(Dien)(Nucleobase) (2+) For Hivncp7 Targeting, S. D. Tsotsoros, P. B. Lutz, A. G. Daniel, E. J. Peterson, R. E. F. De Paiva, E. Rivera, Y. Qu, C. A. Bayse, N. P. Farrell
Enhancement Of The Physicochemical Properties Of Pt(Dien)(Nucleobase) (2+) For Hivncp7 Targeting, S. D. Tsotsoros, P. B. Lutz, A. G. Daniel, E. J. Peterson, R. E. F. De Paiva, E. Rivera, Y. Qu, C. A. Bayse, N. P. Farrell
Chemistry & Biochemistry Faculty Publications
Physicochemical properties of coordination compounds can be exploited for molecular recognition of biomolecules. The inherent π-π stacking properties of [Pt(chelate)(N-donor)]2+([PtN4]) complexes were modulated by systematic variation of the chelate (diethylenetriamine and substituted derivatives) and N-donor (nucleobase or nucleoside) in the formally substitution-inert PtN4 coordination sphere. Approaches to target the HIV nucleocapsid protein HIVNCp7 are summarized building on (i) assessment of stacking interactions with simple tryptophan or tryptophan derivatives to (ii) the tryptophan-containing C-terminal zinc finger and (iii) to the full two-zinc finger peptide and its interactions with RNA and DNA. The xanthosine nucleoside was identified …
Synthesis And Characterization Of Amide Linked Triazolyl Glycolipids As Molecular Hydrogelators And Organogelators, Guijun Wang, Anji Chen, Hari P. R. Mangunuru, Jayasudhan Reddy Yerabolu
Synthesis And Characterization Of Amide Linked Triazolyl Glycolipids As Molecular Hydrogelators And Organogelators, Guijun Wang, Anji Chen, Hari P. R. Mangunuru, Jayasudhan Reddy Yerabolu
Chemistry & Biochemistry Faculty Publications
Carbohydrate based small molecular gelators are important classes of compounds which can form useful soft materials with many practical applications. Although many different types of effective gelators have been reported, the rational design of a molecular hydrogelator is still challenging. In this research, we combined the structural features of two classes of monosaccharide based molecular gelators and obtained a new class of glycolipids that can function as molecular gelators. These new compounds were synthesized by introducing a triazole functional group to a protected 2-glucosamine through Cu(i) catalyzed azide/alkyne cycloaddition reaction (CuAAC). A series of eighteen new glycolipids containing 4,6-O …
Redox Active Motifs In Selenoproteins, Fei Li, Yuliya Pepelyayeva, Elias S. J. Arner, Craig A. Bayse, Sharon Rozovsky
Redox Active Motifs In Selenoproteins, Fei Li, Yuliya Pepelyayeva, Elias S. J. Arner, Craig A. Bayse, Sharon Rozovsky
Chemistry & Biochemistry Faculty Publications
Selenoproteins use the rare amino acid selenocysteine (Sec) to act as the first line of defense against oxidants, which are linked to aging, cancer, and neurodegenerative diseases. Many selenoproteins are oxidoreductases in which the reactive Sec is connected to a neighboring Cys and able to form a ring. These Sec-containing redox motifs govern much of the reactivity of selenoproteins. To study their fundamental properties, we have used Se-77 NMR spectroscopy in concert with theoretical calculations to determine the conformational preferences and mobility of representative motifs. This use of Se-77 as a probe enables the direct recording of the properties of …
The Relative Contribution Of Methanotrophs To Microbial Communities And Carbon Cycling In Soil Overlying A Coal-Bed Methane Seep, Christopher T. Mills, Gregpry F. Slater, Robert F. Dias, Stephanie A. Carr, Christopher M. Reddy, Raleigh Schmidt, Kevin W. Mandernack
The Relative Contribution Of Methanotrophs To Microbial Communities And Carbon Cycling In Soil Overlying A Coal-Bed Methane Seep, Christopher T. Mills, Gregpry F. Slater, Robert F. Dias, Stephanie A. Carr, Christopher M. Reddy, Raleigh Schmidt, Kevin W. Mandernack
Chemistry & Biochemistry Faculty Publications
Seepage of coal-bed methane (CBM) through soils is a potential source of atmospheric CH4 and also a likely source of ancient (i.e. 14C-dead) carbon to soil microbial communities. Natural abundance 13C and 14C compositions of bacterial membrane phospholipid fatty acids (PLFAs) and soil gas CO2 and CH4 were used to assess the incorporation of CBM-derived carbon into methanotrophs and other members of the soil microbial community. Concentrations of type I and type II methanotroph PLFA biomarkers (16:1ω8c and 18:1ω8c, respectively) were elevated in CBM-impacted soils compared with a control site. Comparison …
Real-Time In Vivo Imaging Of Size-Dependent Transport And Toxicity Of Gold Nanoparticles In Zebrafish Embryos Using Single Nanoparticle Plasmonic Spectroscopy, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu
Real-Time In Vivo Imaging Of Size-Dependent Transport And Toxicity Of Gold Nanoparticles In Zebrafish Embryos Using Single Nanoparticle Plasmonic Spectroscopy, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu
Chemistry & Biochemistry Faculty Publications
Noble metal nanoparticles (NPs) show distinctive plasmonic optical properties and superior photostability, enabling them to serve as photostable multicoloured optical molecular probes and sensors for real-time in vivo imaging. To effectively study biological functions in vivo, it is essential that the NP probes are biocompatible and can be delivered into living organisms non-invasively. In this study, we have synthesized, purified and characterized stable (non-aggregated) gold (Au) NPs (86.2 +/- 10.8 nm). We have developed dark-field single NP plasmonic microscopy and spectroscopy to study their transport into early developing zebrafish embryos (cleavage stage) and their effects on embryonic development …
Protein Folding By 'Levels Of Separation': A Hypothesis, Lesley H. Greene, Terri M. Grant
Protein Folding By 'Levels Of Separation': A Hypothesis, Lesley H. Greene, Terri M. Grant
Chemistry & Biochemistry Faculty Publications
The protein folding process has been studied both computationally and experimentally for over 30 years. To date there is no detailed mechanism to explain the formation of long-range interactions between the transition and native states. Long-range interactions are the principle determinants of the tertiary structure. We present a theoretical model which proposes a mechanism for the acquisition of these interactions as they form in a modified version of ‘degrees of separation’, that we term ‘levels of separation’. It is based on the integration of network science and biochemistry. (C) 2012 Federation of European Biochemical Societies.
Protein Structure Networks, Lesley H. Greene
Protein Structure Networks, Lesley H. Greene
Chemistry & Biochemistry Faculty Publications
The application of the field of network science to the scientific disciplines of structural biology and biochemistry, have yielded important new insights into the nature and determinants of protein structures, function, dynamics and the folding process. Advancements in further understanding protein relationships through network science have also reshaped the way we view the connectivity of proteins in the protein universe. The canonical hierarchical classification can now be visualized for example, as a protein fold continuum. This review will survey several key advances in the expanding area of research being conducted to study protein structures and folding using network approaches.
Electric Pulses To Prepare Feeder Cells For Sustaining And Culturing Of Undifferentiated Embryonic Stem Cells, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu
Electric Pulses To Prepare Feeder Cells For Sustaining And Culturing Of Undifferentiated Embryonic Stem Cells, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu
Chemistry & Biochemistry Faculty Publications
Current challenges in embryonic-stem-cell (ESC) research include inability of sustaining and culturing of undifferentiated ESCs over time. Growth-arrested feeder cells are essential to the culture and sustaining of undifferentiated ESCs, and they are currently prepared using gammaradiation and chemical inactivation. Both techniques have severe limitations. In this study, we developed a new, simple and effective technique (pulsed-electric-fields, PEFs) to produce viable growth-arrested cells (RTS34st) and used them as high-quality feeder cells to culture and sustain undifferentiated zebrafish ESCs over time. The cells were exposed to 25 sequential 10- nanosecond-electric-pulses (10nsEPs) of 25, 40 and 150 kV/cm with 1s pulse interval, …
Theoretical Studies Of 2,3 -Sigmatropic Rearrangements Of Allylic Selenoxides And Selenimides, Craig A. Bayse, Sonia Antony
Theoretical Studies Of 2,3 -Sigmatropic Rearrangements Of Allylic Selenoxides And Selenimides, Craig A. Bayse, Sonia Antony
Chemistry & Biochemistry Faculty Publications
Density-functional theory is used to model the endo and exo transition states for [2,3]-sigmatropic rearrangement of allylic aryl-selenoxides and -selenimides. The endo transition state is generally preferred for selenoxides if there is no substitution at the 2 position of the allyl group. Based upon the relative energies of the endo and exo transition states, enantioselectivity of rearrangements is expected to be greatest for molecules with substitutions at the 1- or (E)-3- position of the allyl group. Ortho substitution of a nitro group on the ancillary selenoxide phenyl ring reduces the activation barriers, increases the difference between the endo and exo …
Naturally Present Fatty Acids As Internal Calibrants For Fourier Transform Mass Spectra Of Dissolved Organic Matter, Rachel L. Sleighter, Georgina A. Mckee, Zhanfei Liu, Patrick G. Hatcher
Naturally Present Fatty Acids As Internal Calibrants For Fourier Transform Mass Spectra Of Dissolved Organic Matter, Rachel L. Sleighter, Georgina A. Mckee, Zhanfei Liu, Patrick G. Hatcher
Chemistry & Biochemistry Faculty Publications
The analysis of dissolved organic matter ( DOM) by Fourier transform ion cyclotron resonance mass spectrometry ( FTICR- MS) has gained wide interest recently, driven primarily by its ultrahigh resolving power and mass accuracy. Accurate calibration of mass spectra is a key step to successfully decipher the DOM components. We propose a simple and accurate method to internally calibrate the peaks in the complex spectra without the need to add a calibrant. Mass spectra of DOM samples from the Dismal Swamp, Virginia, and the lower Chesapeake Bay display the presence of naturally occurring fatty acids which can be readily recognized …
In Vivo Imaging Of Transport And Biocompatibility Of Single Silver Nanoparticles In Early Development Of Zebrafish Embryos, Kerry J. Lee, Prakash D. Nallathamby, Lauren M. Browning, Christopher J. Osgood, Xiao-Hong Nancy Xu
In Vivo Imaging Of Transport And Biocompatibility Of Single Silver Nanoparticles In Early Development Of Zebrafish Embryos, Kerry J. Lee, Prakash D. Nallathamby, Lauren M. Browning, Christopher J. Osgood, Xiao-Hong Nancy Xu
Chemistry & Biochemistry Faculty Publications
Real-time study of the transport and biocompatibility of nanomaterials in early embryonic development at single-nanoparticle resolution can offer new knowledge about the delivery and effects of nanomaterials in vivo, and provide new insights into molecular transport mechanisms in developing embryos. In this study, we directly characterized the transport of single silver nanoparticles into an in vivo model system (zebrafish embryos) and investigated their effects on early embryonic development at single-nanoparticle resolution in real time. We designed highly purified and stable (not aggregated and no photodecomposition) nanoparticles and developed single-nanoparticle optics and in vivo assays to enable the study. We …
The Application Of Electrospray Ionization Coupled To Ultrahigh Resolution Mass Spectrometry For The Molecular Characterization Of Natural Organic Matter, Rachel L. Sleighter, Patrick G. Hatcher
The Application Of Electrospray Ionization Coupled To Ultrahigh Resolution Mass Spectrometry For The Molecular Characterization Of Natural Organic Matter, Rachel L. Sleighter, Patrick G. Hatcher
Chemistry & Biochemistry Faculty Publications
Mass spectrometry has recently played a key role in the understanding of natural organic matter (NOM) by providing molecular-level details about its composition. NOM, a complex assemblage of organic molecules present in natural waters and soils/sediments, has the ability to bind and transport anthropogenic materials. An improved understanding of its composition is crucial in order to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles. In the past, low-resolution (> 3000) mass analyzers have offered some insights into the structure of NOM, but emerging ultrahigh resolution (> 200000) techniques such as electrospray ionization (ESI) coupled …