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Articles 1 - 15 of 15
Full-Text Articles in Chemistry
The Catalytic Mechanism Of Electron-Bifurcating Electron Transfer Flavoproteins (Etfs) Involves An Intermediary Complex With Nad+, Gerrit J. Schut, Nishya Mohamed-Raseek, Monika Tokmina-Lukaszewska, David W. Mulder, Diep M. N. Nguyen, Gina L. Lipscomb, John Patrick Hoben, Angela Patterson, Carolyn E. Lubner, Paul W. King, John W. Peters, Brian Bothner, Anne-Frances Miller, Michael W. W. Adams
The Catalytic Mechanism Of Electron-Bifurcating Electron Transfer Flavoproteins (Etfs) Involves An Intermediary Complex With Nad+, Gerrit J. Schut, Nishya Mohamed-Raseek, Monika Tokmina-Lukaszewska, David W. Mulder, Diep M. N. Nguyen, Gina L. Lipscomb, John Patrick Hoben, Angela Patterson, Carolyn E. Lubner, Paul W. King, John W. Peters, Brian Bothner, Anne-Frances Miller, Michael W. W. Adams
Chemistry Faculty Publications
Electron bifurcation plays a key role in anaerobic energy metabolism, but it is a relatively new discovery, and only limited mechanistic information is available on the diverse enzymes that employ it. Herein, we focused on the bifurcating electron transfer flavoprotein (ETF) from the hyperthermophilic archaeon Pyrobaculum aerophilum. The EtfABCX enzyme complex couples NADH oxidation to the endergonic reduction of ferredoxin and exergonic reduction of menaquinone. We developed a model for the enzyme structure by using nondenaturing MS, cross-linking, and homology modeling in which EtfA, -B, and -C each contained FAD, whereas EtfX contained two [4Fe-4S] clusters. On the basis …
Canvass: A Crowd-Sourced, Natural-Product Screening Library For Exploring Biological Space, Sara E. Kearney, Gergely ZahoráNszky-KőHalmi, Kyle R. Brimacombe, Mark J. Henderson, Caitlin Lynch, Tongan Zhao, Kanny K. Wan, Zina Itkin, Christopher Dillon, Min Shen, Dorian M. Cheff, Tobie D. Lee, Danielle Bougie, Ken Cheng, Nathan P. Coussens, Dorjbal Dorjsuren, Richard T. Eastman, Ruili Huang, Michael J. Iannotti, Surendra Karavadhi, Carleen Klumpp-Thomas, Jacob S. Roth, Srilatha Sakamuru, Wei Sun, Steven A. Titus, Adam Yasgar, Ya-Qin Zhang, Jinghua Zhao, Rodrigo B. Andrade, M. Kevin Brown, Robert B. Grossman
Canvass: A Crowd-Sourced, Natural-Product Screening Library For Exploring Biological Space, Sara E. Kearney, Gergely ZahoráNszky-KőHalmi, Kyle R. Brimacombe, Mark J. Henderson, Caitlin Lynch, Tongan Zhao, Kanny K. Wan, Zina Itkin, Christopher Dillon, Min Shen, Dorian M. Cheff, Tobie D. Lee, Danielle Bougie, Ken Cheng, Nathan P. Coussens, Dorjbal Dorjsuren, Richard T. Eastman, Ruili Huang, Michael J. Iannotti, Surendra Karavadhi, Carleen Klumpp-Thomas, Jacob S. Roth, Srilatha Sakamuru, Wei Sun, Steven A. Titus, Adam Yasgar, Ya-Qin Zhang, Jinghua Zhao, Rodrigo B. Andrade, M. Kevin Brown, Robert B. Grossman
Chemistry Faculty Publications
Natural products and their derivatives continue to be wellsprings of nascent therapeutic potential. However, many laboratories have limited resources for biological evaluation, leaving their previously isolated or synthesized compounds largely or completely untested. To address this issue, the Canvass library of natural products was assembled, in collaboration with academic and industry researchers, for quantitative high-throughput screening (qHTS) across a diverse set of cell-based and biochemical assays. Characterization of the library in terms of physicochemical properties, structural diversity, and similarity to compounds in publicly available libraries indicates that the Canvass library contains many structural elements in common with approved drugs. The …
Data On Spectrum-Based Fluorescence Resonance Energy Transfer Measurement Of E. Coli Multidrug Transporter Acrb, Yuguang Cai, Thomas E. Wilkop, Yinan Wei
Data On Spectrum-Based Fluorescence Resonance Energy Transfer Measurement Of E. Coli Multidrug Transporter Acrb, Yuguang Cai, Thomas E. Wilkop, Yinan Wei
Chemistry Faculty Publications
This paper presented the dataset of correction parameters used in the determination of the energy transfer efficiencies from the spectrum-based fluorescence resonance energy transfer (FRET) measurement in a trimeric membrane protein AcrB. The cyan fluorescent protein (CFP) and yellow fluorescent protein (YPet) were used as the donor and acceptor, respectively. Two AcrB fusion proteins were constructed, AcrB-CFP and AcrB-YPet. The proteins were co-expressed in Escherichia coli cells, and energy transfer efficiency were determined in live cells. To obtain reliable energy transfer data, a complete set of correction parameters need to be first determined to accommodate for factors such as background …
Decreasing Phosphatidylcholine On The Surface Of The Lipid Droplet Correlates With Altered Protein Binding And Steatosis, Laura Listenberger, Elizabeth Townsend, Cassandra Rickertsen, Anastasia Hains, Elizabeth Brown, Emily G. Inwards, Angela K. Stoeckman
Decreasing Phosphatidylcholine On The Surface Of The Lipid Droplet Correlates With Altered Protein Binding And Steatosis, Laura Listenberger, Elizabeth Townsend, Cassandra Rickertsen, Anastasia Hains, Elizabeth Brown, Emily G. Inwards, Angela K. Stoeckman
Chemistry Faculty Publications
Alcoholic fatty liver disease (AFLD) is characterized by an abnormal accumulation of lipid droplets (LDs) in the liver. Here, we explore the composition of hepatic LDs in a rat model of AFLD. Five to seven weeks of alcohol consumption led to significant increases in hepatic triglyceride mass, along with increases in LD number and size. Additionally, hepatic LDs from rats with early alcoholic liver injury show a decreased ratio of surface phosphatidylcholine (PC) to phosphatidylethanolamine (PE). This occurred in parallel with an increase in the LD association of perilipin 2, a prominent LD protein. To determine if changes to the …
Intranasal Rapamycin Ameliorates Alzheimer-Like Cognitive Decline In A Mouse Model Of Down Syndrome, Antonella Tramutola, Chiara Lanzillotta, Eugenio Barone, Andrea Arena, Ilaria Zuliani, Luciana Mosca, Carla Blarzino, D. Allan Butterfield, Marzia Perluigi, Fabio Di Domenico
Intranasal Rapamycin Ameliorates Alzheimer-Like Cognitive Decline In A Mouse Model Of Down Syndrome, Antonella Tramutola, Chiara Lanzillotta, Eugenio Barone, Andrea Arena, Ilaria Zuliani, Luciana Mosca, Carla Blarzino, D. Allan Butterfield, Marzia Perluigi, Fabio Di Domenico
Chemistry Faculty Publications
Background: Down syndrome (DS) individuals, by the age of 40s, are at increased risk to develop Alzheimer-like dementia, with deposition in brain of senile plaques and neurofibrillary tangles. Our laboratory recently demonstrated the disturbance of PI3K/AKT/mTOR axis in DS brain, prior and after the development of Alzheimer Disease (AD). The aberrant modulation of the mTOR signalling in DS and AD age-related cognitive decline affects crucial neuronal pathways, including insulin signaling and autophagy, involved in pathology onset and progression. Within this context, the therapeutic use of mTOR-inhibitors may prevent/attenuate the neurodegenerative phenomena. By our work we aimed to rescue mTOR signalling …
Manganese Oxide/Hemin-Functionalized Graphene As A Platform For Peroxynitrite Sensing, Haitham F. Kalil, Shaimaa Maher, Tiyash Bose, Mekki Bayachou
Manganese Oxide/Hemin-Functionalized Graphene As A Platform For Peroxynitrite Sensing, Haitham F. Kalil, Shaimaa Maher, Tiyash Bose, Mekki Bayachou
Chemistry Faculty Publications
Peroxynitrite (ONOO−, PON) is a powerful oxidizing agent generated in vivo by the diffusion-limited reaction of nitric oxide (NO) and superoxide (O2˙−) radicals. Under oxidative stress, cumulated peroxynitrite levels are associated with chronic inflammatory disorders and other pathophysiological conditions. The accurate detection of peroxynitrite in biological systems is important, not only to understand the genesis and development of diseases, but also to explore and design potential therapeutics. Herein, a manganese oxide/hemin-modified graphene interface is explored as a platform for peroxynitrite amperometric detection. Hemin-functionalized reduced graphene oxide was further modified with manganese oxide nanoparticles to provide a …
Doxorubicin-Induced Elevated Oxidative Stress And Neurochemical Alterations In Brain And Cognitive Decline: Protection By Mesna And Insights Into Mechanisms Of Chemotherapy-Induced Cognitive Impairment ("Chemobrain"), Jeriel T. R. Keeney, Xiaojia Ren, Govind Warrier, Teresa Noel, David K. Powell, Jennifer M. Brelsfoard, Rukhsana Sultana, Kathryn E. Saatman, Daret K. St. Clair, D. Allan Butterfield
Doxorubicin-Induced Elevated Oxidative Stress And Neurochemical Alterations In Brain And Cognitive Decline: Protection By Mesna And Insights Into Mechanisms Of Chemotherapy-Induced Cognitive Impairment ("Chemobrain"), Jeriel T. R. Keeney, Xiaojia Ren, Govind Warrier, Teresa Noel, David K. Powell, Jennifer M. Brelsfoard, Rukhsana Sultana, Kathryn E. Saatman, Daret K. St. Clair, D. Allan Butterfield
Chemistry Faculty Publications
Chemotherapy-induced cognitive impairment (CICI) is now widely recognized as a real and too common complication of cancer chemotherapy experienced by an ever-growing number of cancer survivors. Previously, we reported that doxorubicin (Dox), a prototypical reactive oxygen species (ROS)-producing anti-cancer drug, results in oxidation of plasma proteins, including apolipoprotein A-I (ApoA-I) leading to tumor necrosis factor-alpha (TNF-α)-mediated oxidative stress in plasma and brain. We also reported that co-administration of the antioxidant drug, 2-mercaptoethane sulfonate sodium (MESNA), prevents Dox-induced protein oxidation and subsequent TNF-α elevation in plasma. In this study, we measured oxidative stress in both brain and plasma of Dox-treated mice …
Cross Photoreaction Of Glyoxylic And Pyruvic Acids In Model Aqueous Aerosol, Sha-Sha Xia, Alexis J. Eugene, Marcelo I. Guzman
Cross Photoreaction Of Glyoxylic And Pyruvic Acids In Model Aqueous Aerosol, Sha-Sha Xia, Alexis J. Eugene, Marcelo I. Guzman
Chemistry Faculty Publications
Aerosols of variable composition, size, and shape are associated with public health concerns as well as with light-particle interactions that play a role in the energy balance of the atmosphere. Photochemical reactions of 2-oxocarboxylic acids in the aqueous phase are now known to contribute to the total secondary organic aerosol (SOA) budget. This work explores the cross reaction of glyoxylic acid (GA) and pyruvic acid (PA) in water, the two most abundant 2-oxocarboxylic acids in the atmosphere, under solar irradiation and dark thermal aging steps. During irradiation, PA and GA are excited and initiate proton-coupled electron transfer or hydrogen abstraction …
N-Glycosylation In The Protease Domain Of Trypsin-Like Serine Proteases Mediates Calnexin-Assisted Protein Folding, Hao Wang, Shuo Li, Juejin Wang, Shenghan Chen, Xue-Long Sun, Qingyu Wu
N-Glycosylation In The Protease Domain Of Trypsin-Like Serine Proteases Mediates Calnexin-Assisted Protein Folding, Hao Wang, Shuo Li, Juejin Wang, Shenghan Chen, Xue-Long Sun, Qingyu Wu
Chemistry Faculty Publications
Trypsin-like serine proteases are essential in physiological processes. Studies have shown that N-glycans are important for serine protease expression and secretion, but the underlying mechanisms are poorly understood. Here, we report a common mechanism of N-glycosylation in the protease domains of corin, enteropeptidase and prothrombin in calnexin-mediated glycoprotein folding and extracellular expression. This mechanism, which is independent of calreticulin and operates in a domain-autonomous manner, involves two steps: direct calnexin binding to target proteins and subsequent calnexin binding to monoglucosylated N-glycans. Elimination of N-glycosylation sites in the protease domains of corin, enteropeptidase and prothrombin inhibits corin and enteropeptidase cell surface …
Biochar From Waste Banana Peels As Growth Promoter For Holy Basil (Ocimum Tenuiflorum) And Chili Pepper (Capsicum Annuum), Regina C. So, N Tan
Biochar From Waste Banana Peels As Growth Promoter For Holy Basil (Ocimum Tenuiflorum) And Chili Pepper (Capsicum Annuum), Regina C. So, N Tan
Chemistry Faculty Publications
Biochars are porous materials prepared by combustion of biomass under the presence of low oxygen levels. Its application as soil fertilizer has been shown to have positive effects on the plants by increasing the fertility and raising the soil pH, increasing nutrient cycling and moisture holding capacity, improving cation exchange capacity, and reducing the amount of pesticides and nutrients leaching to the surface and ground water (Laird 2008, Speratti 2017). In this study, waste banana peels of the Lakatan variety (Musa x paradisiaca) were pyrolized at temperatures 300, 400, 500 and 700 °C, the resulting basic char were obtained at …
Mammalian Cell-Derived Vesicles For The Isolation Of Organelle Specific Transmembrane Proteins To Conduct Single Molecule Studies, Faruk H. Moonschi, Ashley M. Fox-Loe, Xu Fu, Christopher I. Richards
Mammalian Cell-Derived Vesicles For The Isolation Of Organelle Specific Transmembrane Proteins To Conduct Single Molecule Studies, Faruk H. Moonschi, Ashley M. Fox-Loe, Xu Fu, Christopher I. Richards
Chemistry Faculty Publications
Cell-derived vesicles facilitate the isolation of transmembrane proteins in their physiological membrane maintaining their structural and functional integrity. These vesicles can be generated from different cellular organelles producing, housing, or transporting the proteins. Combined with single molecule imaging, isolated organelle specific vesicles can be employed to study the trafficking and assembly of the embedded proteins. Here we present a method for organelle specific single molecule imaging via isolation of ER and plasma membrane vesicles from HEK293T cells by employing OptiPrep gradients and nitrogen cavitation. The isolation was validated through Western blotting, and the isolated vesicles were used to perform single …
Untargeted Bioassay Strategy For Medicinal Plants: In Vitro Antidiabetic Activity And 13c Nmr Profiling Of Extracts From Vitex Negundo L, Fabian M. Dayrit, Myrnille Joy B. Zabala, Lolita G. Lagurin
Untargeted Bioassay Strategy For Medicinal Plants: In Vitro Antidiabetic Activity And 13c Nmr Profiling Of Extracts From Vitex Negundo L, Fabian M. Dayrit, Myrnille Joy B. Zabala, Lolita G. Lagurin
Chemistry Faculty Publications
Bioassay-guided fractionation is the principal method for the identification of active constituents in medicinal plants. By design, this method aims to identify the most active compound in a complex mixture with the objective of discovering novel drug candidates. Described here is a complementary method for the identification of known bioactive compounds in medicinal plants which is untargeted and which takes advantage of the large NMR database of known natural products and availability of statistical software. This untargeted bioassay strategy is demonstrated as a proof of principle in the determination of the antidiabetic compounds in Vitex negundo L. Crude methanol and …
Distinct Properties Underlie Flavin-Based Electron Bifurcation In A Novel Electron Transfer Flavoprotein Fixab From Rhodopseudomonas Palustris, H. Diessel Duan, Carolyn E. Lubner, Monika Tokmina-Lukaszewska, George H. Gauss, Brian Bothner, Paul W. King, John W. Peters, Anne-Frances Miller
Distinct Properties Underlie Flavin-Based Electron Bifurcation In A Novel Electron Transfer Flavoprotein Fixab From Rhodopseudomonas Palustris, H. Diessel Duan, Carolyn E. Lubner, Monika Tokmina-Lukaszewska, George H. Gauss, Brian Bothner, Paul W. King, John W. Peters, Anne-Frances Miller
Chemistry Faculty Publications
A newly recognized third fundamental mechanism of energy conservation in biology, electron bifurcation, uses free energy from exergonic redox reactions to drive endergonic redox reactions. Flavin-based electron bifurcation furnishes low-potential electrons to demanding chemical reactions, such as reduction of dinitrogen to ammonia. We employed the heterodimeric flavoenzyme FixAB from the diazotrophic bacterium Rhodopseudomonas palustris to elucidate unique properties that underpin flavin-based electron bifurcation. FixAB is distinguished from canonical electron transfer flavoproteins (ETFs) by a second FAD that replaces the AMP of canonical ETF. We exploited near-UV–visible CD spectroscopy to resolve signals from the different flavin sites in FixAB and to …
Informing Efforts To Develop Nitroreductase For Amine Production, Anne-Frances Miller, Jonathan T. Park, Kyle L. Ferguson, Warintra Pitsawong, Andreas S. Bommarius
Informing Efforts To Develop Nitroreductase For Amine Production, Anne-Frances Miller, Jonathan T. Park, Kyle L. Ferguson, Warintra Pitsawong, Andreas S. Bommarius
Chemistry Faculty Publications
Nitroreductases (NRs) hold promise for converting nitroaromatics to aromatic amines. Nitroaromatic reduction rate increases with Hammett substituent constant for NRs from two different subgroups, confirming substrate identity as a key determinant of reactivity. Amine yields were low, but compounds yielding amines tend to have a large π system and electron withdrawing substituents. Therefore, we also assessed the prospects of varying the enzyme. Several different subgroups of NRs include members able to produce aromatic amines. Comparison of four NR subgroups shows that they provide contrasting substrate binding cavities with distinct constraints on substrate position relative to the flavin. The unique architecture …
A Galactomannoglucan Derived From Agaricus Brasiliensis: Purification, Characterization And Macrophage Activation Via Mapk And Ikappab/Nfkappab Pathways, Yanqing Zhang, Danting Liu, Leilei Fang, Xiaotong Zhao, Aimin Zhou, Junbo Xie
A Galactomannoglucan Derived From Agaricus Brasiliensis: Purification, Characterization And Macrophage Activation Via Mapk And Ikappab/Nfkappab Pathways, Yanqing Zhang, Danting Liu, Leilei Fang, Xiaotong Zhao, Aimin Zhou, Junbo Xie
Chemistry Faculty Publications
In this study, a novel galactomannoglucan named as TJ2 was isolated from Agaricus brasiliensis with microwave extraction, macroporous resin, ion exchange resin and high resolution gel chromatography. TJ2 is composed of glucose, mannose and galactose in the ratio 99.2:0.2:0.6. Infrared spectra (IR), methylation analysis and nuclear magnetic resonance spectra indicated that TJ2 mainly contained a b-(1?3) – linked glucopyranosyl backbone. Interestingly, TJ2 significantly promoted RAW264.7 cell proliferation, and was able to activate the cells to engulf E. coli. In addition, TJ2 induced the expression of Interleukin 1b (IL-1b), Interleukin 6 (IL-6), tumor necrosis factor a (TNF-a) and cyclooxygenase-2 (Cox-2) in …