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Full-Text Articles in Biochemistry

Structural Analysis Of Neutralizing Epitopes Of The Sars-Cov-2 Spike To Guide Therapy And Vaccine Design Strategies, Maxwell T. Finkelstein , '22, Adam G. Mermelstein , '21, Emma Parker Miller , '22, Paul C. Seth , '22, Erik-Stephane D. Stancofski , '21, Daniela Fera Jan 2021

Structural Analysis Of Neutralizing Epitopes Of The Sars-Cov-2 Spike To Guide Therapy And Vaccine Design Strategies, Maxwell T. Finkelstein , '22, Adam G. Mermelstein , '21, Emma Parker Miller , '22, Paul C. Seth , '22, Erik-Stephane D. Stancofski , '21, Daniela Fera

Chemistry & Biochemistry Faculty Works

Coronavirus research has gained tremendous attention because of the COVID-19 pandemic, caused by the novel severe acute respiratory syndrome coronavirus (nCoV or SARS-CoV-2). In this review, we highlight recent studies that provide atomic-resolution structural details important for the development of monoclonal antibodies (mAbs) that can be used therapeutically and prophylactically and for vaccines against SARS-CoV-2. Structural studies with SARS-CoV-2 neutralizing mAbs have revealed a diverse set of binding modes on the spike’s receptor-binding domain and N-terminal domain and highlight alternative targets on the spike. We consider this structural work together with mAb effects in vivo to suggest correlations between structure …


Structure-Guided Molecular Grafting Of A Complex Broadly Neutralizing Viral Epitope, G. Bajic, M. J. Maron, T. M. Caradonna, M. Tian, Adam Mermelstein , '21, Daniela Fera, G. Kelsoe, M. Kuraoka, A. G. Schmidt Jan 2020

Structure-Guided Molecular Grafting Of A Complex Broadly Neutralizing Viral Epitope, G. Bajic, M. J. Maron, T. M. Caradonna, M. Tian, Adam Mermelstein , '21, Daniela Fera, G. Kelsoe, M. Kuraoka, A. G. Schmidt

Chemistry & Biochemistry Faculty Works

Antigenic variation and viral evolution have thwarted traditional influenza vaccination strategies. The broad protection afforded by a “universal” influenza vaccine may come from immunogens that elicit humoral immune responses targeting conserved epitopes on the viral hemagglutinin (HA), such as the receptor-binding site (RBS). Here, we engineered candidate immunogens that use noncirculating, avian influenza HAs as molecular scaffolds to present the broadly neutralizing RBS epitope from historical, circulating H1 influenzas. These “resurfaced” HAs (rsHAs) remove epitopes potentially targeted by strain-specific responses in immune-experienced individuals. Through structure-guided optimization, we improved two antigenically different scaffolds to bind a diverse panel of pan-H1 and …


The Effects Of Framework Mutations At The Variable Domain Interface On Antibody Affinity Maturation In An Hiv-1 Broadly Neutralizing Antibody Lineage, Jeffrey O. Zhou , '19, Hussain A. Zaidi , '22, Therese Ton , '19, Daniela Fera Jan 2020

The Effects Of Framework Mutations At The Variable Domain Interface On Antibody Affinity Maturation In An Hiv-1 Broadly Neutralizing Antibody Lineage, Jeffrey O. Zhou , '19, Hussain A. Zaidi , '22, Therese Ton , '19, Daniela Fera

Chemistry & Biochemistry Faculty Works

Understanding affinity maturation of antibodies that can target many variants of HIV-1 is important for vaccine development. While the antigen-binding site of antibodies is known to mutate throughout the co-evolution of antibodies and viruses in infected individuals, the roles of the mutations in the antibody framework region are not well understood. Throughout affinity maturation, the CH103 broadly neutralizing antibody lineage, from an individual designated CH505, altered the orientation of one of its antibody variable domains. The change in orientation was a response to insertions in the variable loop 5 (V5) of the HIV envelope. In this study, we generated CH103 …


Nanomaterials For Biosensing Lipopolysaccharide, Palak Sondhi, Helal Maruf, Keith Stine Dec 2019

Nanomaterials For Biosensing Lipopolysaccharide, Palak Sondhi, Helal Maruf, Keith Stine

Chemistry & Biochemistry Faculty Works

Lipopolysaccharides (LPS) are endotoxins, hazardous and toxic inflammatory stimulators released from the outer membrane of Gram-negative bacteria, and are the major cause of septic shock giving rise to millions of fatal illnesses worldwide. There is an urgent need to identify and detect these molecules selectively and rapidly. Pathogen detection has been done by traditional as well as biosensor-based methods. Nanomaterial based biosensors can assist in achieving these goals and have tremendous potential. The biosensing techniques developed are low-cost, easy to operate, and give a fast response. Due to extremely small size, large surface area, and scope for surface modification, nanomaterials …


Selective Alteration Of The Root Morphology Of Arabidopsis Thaliana By Synthetic Anion Transporters (Sats), Mohit Patel, Evan Garrad, Steven Korb, Saeedeh Negin, Michael Gokel, Sergey Sedinkin, Shanheng Yin, George Gokel Aug 2019

Selective Alteration Of The Root Morphology Of Arabidopsis Thaliana By Synthetic Anion Transporters (Sats), Mohit Patel, Evan Garrad, Steven Korb, Saeedeh Negin, Michael Gokel, Sergey Sedinkin, Shanheng Yin, George Gokel

Chemistry & Biochemistry Faculty Works

No abstract provided.


Identification Of Novel Autoinducer-2 Receptors In Clostridia Reveals Plasticity In The Binding Site Of The Lsrb Receptor Family, I. M. Torcato, M. R. Kasal, P. H. Brito, Stephen T. Miller, K. B. Xavier Mar 2019

Identification Of Novel Autoinducer-2 Receptors In Clostridia Reveals Plasticity In The Binding Site Of The Lsrb Receptor Family, I. M. Torcato, M. R. Kasal, P. H. Brito, Stephen T. Miller, K. B. Xavier

Chemistry & Biochemistry Faculty Works

Autoinducer-2 (AI-2) is unique among quorum-sensing signaling molecules, as it is produced and recognized by a wide variety of bacteria and thus facilitates interspecies communication. To date, two classes of AI-2 receptors have been identified: the LuxP-type, present in the Vibrionales, and the LsrB-type, found in a number of phylogenetically distinct bacterial families. Recently, AI-2 was shown to affect the colonization levels of a variety of bacteria in the microbiome of the mouse gut, including members of the genus Clostridium, but no AI-2 receptor had been identified in this genus. Here, we identify a noncanonical, functional LsrB-type receptor in Clostridium …


Generating High-Order Optical And Spin Harmonics From Ferromagnetic Monolayers, G.P. Zhang, M.S. Si, M. Murakami, Y.H. Bai, Thomas George Dec 2018

Generating High-Order Optical And Spin Harmonics From Ferromagnetic Monolayers, G.P. Zhang, M.S. Si, M. Murakami, Y.H. Bai, Thomas George

Chemistry & Biochemistry Faculty Works

High-order harmonic generation (HHG) in solids has entered a new phase of intensive research, with envisioned band-structure mapping on an ultrashort time scale. This partly benefits from a flurry of new HHG materials discovered, but so far has missed an important group. HHG in magnetic materials should have profound impact on future magnetic storage technology advances. Here we introduce and demonstrate HHG in ferromagnetic monolayers. We find that HHG carries spin information and sensitively depends on the relativistic spin–orbit coupling; and if they are dispersed into the crystal momentum k space, harmonics originating from real transitions can be k-resolved and …


Conjugation Of Nanomaterials And Nematic Liquid Crystals For Futuristic Applications And Biosensors, Thomas George, Amit Choudhary, Guoqiang Li Jul 2018

Conjugation Of Nanomaterials And Nematic Liquid Crystals For Futuristic Applications And Biosensors, Thomas George, Amit Choudhary, Guoqiang Li

Chemistry & Biochemistry Faculty Works

The established role of nematic liquid crystals (NLCs) in the recent rapid development of displays has motivated researchers to modulate the electro-optical properties of LCs. Furthermore, adding nanomaterials into NLCs has led to enhancements of the properties of NLCs, like reduced threshold of the operating voltage, variation in pretilt angle, reduced switching time, etc. These enhanced properties, due to interfacial dynamics, are enabling wider applications of NLCs and nanomaterials. The recent literature of nanomaterial-doped NLCs is rich with various kinds of nanomaterials in a variety of NLCs. The light has been focused on the most widely used and studied gold …


Structural Insights From Hiv-Antibody Co-Evolution And Related Immunization Studies, Jeffrey O. Zhou , '19, Therese Ton , '19, Julia W. Morriss , '19, Diep Nguyen , '19, Daniela Fera Jul 2018

Structural Insights From Hiv-Antibody Co-Evolution And Related Immunization Studies, Jeffrey O. Zhou , '19, Therese Ton , '19, Julia W. Morriss , '19, Diep Nguyen , '19, Daniela Fera

Chemistry & Biochemistry Faculty Works

Human immunodeficiency virus type 1 (HIV-1) is a rapidly evolving pathogen and causes the acquired immunodeficiency syndrome (AIDS) in humans. There are ~30-35 million people infected with HIV around the world, and ~25 million have died since the first reported cases in 1981. Additionally, each year 2-3 million people become newly infected and more than one million die of AIDS. An HIV-1 vaccine would help halt an AIDS pandemic, and efforts to develop a vaccine have focused on targeting the HIV-1 envelope, Env, found on the surface of the virus. A number of chronically infected individuals have been shown to …


Aβ42 Protofibrils Interact With, And Are Trafficked Through, Microglial-Derived Microvesicles, Lisa Gouwens, Mudar Ismail, Victoria Rogers, Nathan Zeller, Evan Garrad, Fatima Amtashar, Nyasha Makoni, David Osborn, Michael Nichols Jun 2018

Aβ42 Protofibrils Interact With, And Are Trafficked Through, Microglial-Derived Microvesicles, Lisa Gouwens, Mudar Ismail, Victoria Rogers, Nathan Zeller, Evan Garrad, Fatima Amtashar, Nyasha Makoni, David Osborn, Michael Nichols

Chemistry & Biochemistry Faculty Works

Microvesicles (MVs) and exosomes comprise a class of cell-secreted particles termed extracellular vesicles (EVs). These cargo-holding vesicles mediate cell-to-cell communication and have recently been implicated in neurodegenerative diseases such as Alzheimer’s disease (AD). The two types of EVs are distinguished by the mechanism of cell release and their size, with the smaller exosomes and the larger MVs ranging from 30 to 100 nm and 100 nm to 1 μm in diameter, respectively. MV numbers are increased in AD and appear to interact with amyloid-β peptide (Aβ), the primary protein component of the neuritic plaques in the AD brain. Because microglial …


Shaping Light In Backward-Wave Nonlinear Hyperbolic Metamaterials, Thomas George, Alexander Popov, Sergey Myslivets, Vitaly Slabko, Victor Tkachenko Apr 2018

Shaping Light In Backward-Wave Nonlinear Hyperbolic Metamaterials, Thomas George, Alexander Popov, Sergey Myslivets, Vitaly Slabko, Victor Tkachenko

Chemistry & Biochemistry Faculty Works

Backward electromagnetic waves are extraordinary waves with contra-directed phase velocity and energy flux. Unusual properties of the coherent nonlinear optical coupling of the phase-matched ordinary and backward electromagnetic waves with contra-directed energy fluxes are described that enable greatly-enhanced frequency and propagation direction conversion, parametrical amplification, as well as control of shape of the light pulses. Extraordinary transient processes that emerge in such metamaterials in pulsed regimes are described. The results of the numerical simulation of particular plasmonic metamaterials with hyperbolic dispersion are presented, which prove the possibility to match phases of such coupled guided ordinary and backward electromagnetic waves. Particular …


Short-Chained Oligo(Ethylene Oxide)-Functionalized Gold Nanoparticles: Realization Of Significant Protein Resistance, Kathryn R. Riley, C. M. Sims, I. T. Wood, D. J. Vanderah, M. L. Walker Jan 2018

Short-Chained Oligo(Ethylene Oxide)-Functionalized Gold Nanoparticles: Realization Of Significant Protein Resistance, Kathryn R. Riley, C. M. Sims, I. T. Wood, D. J. Vanderah, M. L. Walker

Chemistry & Biochemistry Faculty Works

Protein corona formed on nanomaterial surfaces play an important role in the bioavailability and cellular uptake of nanomaterials. Modification of surfaces with oligoethylene glycols (OEG) are a common way to improve the resistivity of nanomaterials to protein adsorption. Short-chain ethylene oxide (EO) oligomers have been shown to improve the protein resistance of planar Au surfaces. We describe the application of these EO oligomers for improved protein resistance of 30 nm spherical gold nanoparticles (AuNPs). Functionalized AuNPs were characterized using UV-Vis spectroscopy, dynamic light scattering (DLS), and zeta potential measurements. Capillary electrophoresis (CE) was used for separation and quantitation of AuNPs …


Redox-Active Nanomaterials For Nanomedicine Applications, C. M. Sims, S. K. Hanna, D. A. Heller, C. P. Horoszko, M. E. Johnson, A. R. Montoro Bustos, V. Reipa, Kathryn R. Riley, B. C. Nelson Oct 2017

Redox-Active Nanomaterials For Nanomedicine Applications, C. M. Sims, S. K. Hanna, D. A. Heller, C. P. Horoszko, M. E. Johnson, A. R. Montoro Bustos, V. Reipa, Kathryn R. Riley, B. C. Nelson

Chemistry & Biochemistry Faculty Works

Nanomedicine utilizes the remarkable properties of nanomaterials for the diagnosis, treatment, and prevention of disease. Many of these nanomaterials have been shown to have robust antioxidative properties, potentially functioning as strong scavengers of reactive oxygen species. Conversely, several nanomaterials have also been shown to promote the generation of reactive oxygen species, which may precipitate the onset of oxidative stress, a state that is thought to contribute to the development of a variety of adverse conditions. As such, the impacts of nanomaterials on biological entities are often associated with and influenced by their specific redox properties. In this review, we overview …


First-Principles And Model Simulation Of All-Optical Spin Reversal, Thomas George, G.P. Zhang, Z. Babyak, Y. Xue, Y. Bai Oct 2017

First-Principles And Model Simulation Of All-Optical Spin Reversal, Thomas George, G.P. Zhang, Z. Babyak, Y. Xue, Y. Bai

Chemistry & Biochemistry Faculty Works

All-optical spin switching is a potential trailblazer for information storage and communication at an unprecedented fast rate free of magnetic fields. However, the current wisdom is largely based on semiempirical models of effective magnetic fields and heat pulses, so it is difficult to provide high-speed design protocols for actual devices. Here, we carry out a massively parallel first-principles and model calculation for 13 spin systems and magnetic layers, free of any effective field, to establish a simpler and alternative paradigm of laser-induced ultrafast spin reversal and to point out a path to a full-integrated photospintronic device. It is the interplay …


Cyclipostins And Cyclophostin Analogs As Promising Compounds In The Fight Against Tuberculosis, Phuong Nguyen, Vincent Delorme, Anaïs Bénarouche, Benjamin Martin, Rishi Paudel, Giri Gnawali, Abdeldjalil Madani, Rémy Puppo, Valérie Landry, Laurent Kremer, Priscille Brodin, Christopher Spilling, Jean-François Cavalier, Stéphane Canaan Jan 2017

Cyclipostins And Cyclophostin Analogs As Promising Compounds In The Fight Against Tuberculosis, Phuong Nguyen, Vincent Delorme, Anaïs Bénarouche, Benjamin Martin, Rishi Paudel, Giri Gnawali, Abdeldjalil Madani, Rémy Puppo, Valérie Landry, Laurent Kremer, Priscille Brodin, Christopher Spilling, Jean-François Cavalier, Stéphane Canaan

Chemistry & Biochemistry Faculty Works

A new class of Cyclophostin and Cyclipostins (CyC) analogs have been investigated against Mycobacterium tuberculosis H37Rv (M. tb) grown either in broth medium or inside macrophages. Our compounds displayed a diversity of action by acting either on extracellular M. tb bacterial growth only, or both intracellularly on infected macrophages as well as extracellularly on bacterial growth with very low toxicity towards host macrophages. Among the eight potential CyCs identified, CyC 17 exhibited the best extracellular antitubercular activity (MIC50 = 500 nM). This compound was selected and further used in a competitive labelling/enrichment assay against the activity-based probe Desthiobiotin-FP in order …


Characterization Of Wy 14,643 And Its Complex With Aldose Reductase, Michael Sawaya, Malkhey Verma, Vaishnavi Balendiran, Nigam Rath, Duilio Cascio, Ganesaratnam Balendiran Dec 2016

Characterization Of Wy 14,643 And Its Complex With Aldose Reductase, Michael Sawaya, Malkhey Verma, Vaishnavi Balendiran, Nigam Rath, Duilio Cascio, Ganesaratnam Balendiran

Chemistry & Biochemistry Faculty Works

The peroxisome proliferator, WY 14,643 exhibits a pure non-competitive inhibition pattern in the aldehyde reduction and in alcohol oxidation activities of human Aldose reductase (hAR). Fluorescence emission measurements of the equilibrium dissociation constants, Kd, of oxidized (hAR•NADP+) and reduced (hAR•NADPH) holoenzyme complexes display a 2-fold difference between them. Kd values for the dissociation of WY 14,643 from the oxidized (hAR•NADP+•WY 14,643) and reduced (hAR•NADPH•WY 14,643) ternary complexes are comparable to each other. The ternary complex structure of hAR•NADP+•WY 14,643 reveals the first structural evidence of a fibrate class drug binding to hAR. These observations demonstrate how fibrate molecules such as …


Conformationally Superarmed S-Ethyl Glycosyl Donors As Effective Building Blocks For Chemoselective Oligosaccharide Synthesis In One Pot, Mithila Bandara, Jagodige Yasomanee, Nigam Rath, Christian Pedersen, Mikael Bols, Alexei Demchenko Nov 2016

Conformationally Superarmed S-Ethyl Glycosyl Donors As Effective Building Blocks For Chemoselective Oligosaccharide Synthesis In One Pot, Mithila Bandara, Jagodige Yasomanee, Nigam Rath, Christian Pedersen, Mikael Bols, Alexei Demchenko

Chemistry & Biochemistry Faculty Works

A new series of superarmed glycosyl donors has been investigated. It was demonstrated that the S-ethyl leaving group allows for high reactivity, which is much higher than that of equally equipped S-phenyl glycosyl donors that were previously investigated by our groups. The superarmed S-ethyl glycosyl donors equipped with a 2-O-benzoyl group gave complete β-stereoselectivity. Utility of the new glycosyl donors has been demonstrated in a one-pot one-addition oligosaccharide synthesis with all of the reaction components present from the beginning.


A Simplified Direct Lipid Mixing Lipoplex Preparation: Comparison Of Liposomal-, Dimethylsulfoxide-, And Ethanol-Based Methods, Joseph Meisel, George Gokel Sep 2016

A Simplified Direct Lipid Mixing Lipoplex Preparation: Comparison Of Liposomal-, Dimethylsulfoxide-, And Ethanol-Based Methods, Joseph Meisel, George Gokel

Chemistry & Biochemistry Faculty Works

Established transfection methodology often uses commercial reagents, which must be formed into liposomes in a sequence of about half a dozen steps. The simplified method reported here is a direct lipid mixing approach that requires fewer steps, less manipulation, and is less time-consuming. Results are comparable to those obtained with more commonly used methods, as judged by a variety of analytical techniques and by comparisons of transfection results. The method reported here may be applied to non-liposome-forming compounds, thereby greatly expanding the range of structures that can be tested for transfection ability.


App Regulates Microglial Phenotype In A Mouse Model Of Alzheimer's Disease, Gunjan Manocha, Angela Floden, Keiko Rausch, Joshua Kulas, Brett Mcgregor, Lalida Rojanathammanee, Kelley Puig, Kendra Puig, Sanjib Karki, Michael Nichols, Diane Darland, James Porter, Colin Combs Aug 2016

App Regulates Microglial Phenotype In A Mouse Model Of Alzheimer's Disease, Gunjan Manocha, Angela Floden, Keiko Rausch, Joshua Kulas, Brett Mcgregor, Lalida Rojanathammanee, Kelley Puig, Kendra Puig, Sanjib Karki, Michael Nichols, Diane Darland, James Porter, Colin Combs

Chemistry & Biochemistry Faculty Works

Prior work suggests that amyloid precursor protein (APP) can function as a proinflammatory receptor on immune cells, such as monocytes and microglia. Therefore, we hypothesized that APP serves this function in microglia during Alzheimer's disease. Although fibrillar amyloid β (Aβ)-stimulated cytokine secretion from both wild-type and APP knock-out (mAPP−/−) microglial cultures, oligomeric Aβ was unable to stimulate increased secretion from mAPP−/− cells. This was consistent with an ability of oligomeric Aβ to bind APP. Similarly, intracerebroventricular infusions of oligomeric Aβ produced less microgliosis in mAPP−/− mice compared with wild-type mice. The mAPP−/− mice crossed to an APP/PS1 transgenic mouse line …


Uplc–Qtof–Ms And Nmr Analyses Of Graviola (Annona Muricata) Leaves, Ingrid De Moraes, Paulo Ribeiro, Flávio Schmidt, Kirley Canuto, Guilherme Zocolo, Edy De Brito, Rensheng Luo, Kristy Richards, Kevin Tran, Robert Smith Mar 2016

Uplc–Qtof–Ms And Nmr Analyses Of Graviola (Annona Muricata) Leaves, Ingrid De Moraes, Paulo Ribeiro, Flávio Schmidt, Kirley Canuto, Guilherme Zocolo, Edy De Brito, Rensheng Luo, Kristy Richards, Kevin Tran, Robert Smith

Chemistry & Biochemistry Faculty Works

No abstract provided.


Interactions Of Two Large Antiviral Polyamides With The Long Control Region Of Hpv16., Elena Vasilieva, Jacquelyn Niederschulte, Yang Song, George Harris, Kevin Koeller, Puhong Liao, James Bashkin, Cynthia Dupureur Jan 2016

Interactions Of Two Large Antiviral Polyamides With The Long Control Region Of Hpv16., Elena Vasilieva, Jacquelyn Niederschulte, Yang Song, George Harris, Kevin Koeller, Puhong Liao, James Bashkin, Cynthia Dupureur

Chemistry & Biochemistry Faculty Works

No abstract provided.


Selection Of A Novel Aptamer Against Vitronectin Using Capillary Electrophoresis And Next Generation Sequencing, C. H. Stuart, Kathryn R. Riley, O. Boyacioglu, D. M. Herpai, W. Debinski, S. Qasem, F. C. Marini, C. L. Colyer, W. H. Gmeiner Jan 2016

Selection Of A Novel Aptamer Against Vitronectin Using Capillary Electrophoresis And Next Generation Sequencing, C. H. Stuart, Kathryn R. Riley, O. Boyacioglu, D. M. Herpai, W. Debinski, S. Qasem, F. C. Marini, C. L. Colyer, W. H. Gmeiner

Chemistry & Biochemistry Faculty Works

Breast cancer (BC) results in ≃40,000 deaths each year in the United States and even among survivors treatment of the disease may have devastating consequences, including increased risk for heart disease and cognitive impairment resulting from the toxic effects of chemotherapy. Aptamer-mediated drug delivery can contribute to improved treatment outcomes through the selective delivery of chemotherapy to BC cells, provided suitable cancer-specific antigens can be identified. We report here the use of capillary electrophoresis in conjunction with next generation sequencing to develop the first vitronectin (VN) binding aptamer (VBA-01; Kd 405 nmol/l, the first aptamer to vitronectin (VN; Kd = …


2-Acylamido Analogues Of N-Acetylglucosamine Prime Formation Of Chitin Oligosaccharides By Yeast Chitin Synthase 2, Jacob Gyore, Archana Parameswar, Carleigh Hebbard, Younghoon Oh, Erfei Bi, Alexei Demchenko, Neil Price, Peter Orlean May 2014

2-Acylamido Analogues Of N-Acetylglucosamine Prime Formation Of Chitin Oligosaccharides By Yeast Chitin Synthase 2, Jacob Gyore, Archana Parameswar, Carleigh Hebbard, Younghoon Oh, Erfei Bi, Alexei Demchenko, Neil Price, Peter Orlean

Chemistry & Biochemistry Faculty Works

Chitin, a homopolymer of β1,4-linked N-acetylglucosamine (GlcNAc) residues, is a key component of the cell walls of fungi and the exoskeletons of arthropods. Chitin synthases transfer GlcNAc from UDP-GlcNAc to preexisting chitin chains in reactions that are typically stimulated by free GlcNAc. The effect of GlcNAc was probed by using a yeast strain expressing a single chitin synthase, Chs2, by examining formation of chitin oligosaccharides (COs) and insoluble chitin, and by replacing GlcNAc with 2-acylamido analogues of GlcNAc. Synthesis of COs was strongly dependent on inclusion of GlcNAc in chitin synthase incubations, and N,N′-diacetylchitobiose (GlcNAc2) was the major reaction product. …


Structural Insights Into The Interaction Between A Potent Anti-Inflammatory Protein, Viral Cc Chemokine Inhibitor (Vcci), And The Human Cc Chemokine, Eotaxin-1, Nai-Wei Kuo, Yong-Guang Gao, Megan Schill, Nancy Isern, Cynthia Dupureur, Patricia Liwang Mar 2014

Structural Insights Into The Interaction Between A Potent Anti-Inflammatory Protein, Viral Cc Chemokine Inhibitor (Vcci), And The Human Cc Chemokine, Eotaxin-1, Nai-Wei Kuo, Yong-Guang Gao, Megan Schill, Nancy Isern, Cynthia Dupureur, Patricia Liwang

Chemistry & Biochemistry Faculty Works

Chemokines play important roles in the immune system, not only recruiting leukocytes to the site of infection and inflammation but also guiding cell homing and cell development. The soluble poxvirus-encoded protein viral CC chemokine inhibitor (vCCI), a CC chemokine inhibitor, can bind to human CC chemokines tightly to impair the host immune defense. This protein has no known homologs in eukaryotes and may represent a potent method to stop inflammation. Previously, our structure of the vCCI·MIP-1β (macrophage inflammatory protein-1β) complex indicated that vCCI uses negatively charged residues in β-sheet II to interact with positively charged residues in the MIP-1β N …


Intrinsic Delocalization During The Decay Of Excitons In Polymeric Solar Cells, Thomas George, W. Chen, D. Jiang, R. Chen, S. Li Jan 2014

Intrinsic Delocalization During The Decay Of Excitons In Polymeric Solar Cells, Thomas George, W. Chen, D. Jiang, R. Chen, S. Li

Chemistry & Biochemistry Faculty Works

In bulk heterojunction polymer solar cells, external photoexcitation results in localized excitons in the polymer chain. After hot exciton formation and subsequent relaxation, the dipole moment drives the electron to partially transfer to extended orbitals from the original localized ones, leading to self-delocalization. Based on the dynamic fluorescence spectra, the delocalization of excitons is revealed to be an intrinsic property dominated by exciton decay, acting as a bridge for the exciton to diffuse in the polymeric solar cell. The modification of the dipole moment enhances the efficiency of polymer solar cells.


Psychosine, The Cytotoxic Sphingolipid That Accumulates In Globoid Cell Leukodystrophy, Alters Membrane Architecture, Jacqueline Hawkins-Salsbury, Archana Parameswar, Xuntian Jiang, Paul Schlesinger, Ernesto Bongarzone, Daniel Ory, Alexei Demchenko, Mark Sands Jan 2013

Psychosine, The Cytotoxic Sphingolipid That Accumulates In Globoid Cell Leukodystrophy, Alters Membrane Architecture, Jacqueline Hawkins-Salsbury, Archana Parameswar, Xuntian Jiang, Paul Schlesinger, Ernesto Bongarzone, Daniel Ory, Alexei Demchenko, Mark Sands

Chemistry & Biochemistry Faculty Works

Globoid cell leukodystrophy (GLD) is a neurological disease caused by deficiency of the lysosomal enzyme galactosylceramidase (GALC). In the absence of GALC, the cytotoxic glycosphingolipid, psychosine (psy), accumulates in the nervous system. Psychosine accumulation preferentially affects oligodendrocytes, leading to progressive demyelination and infiltration of activated monocytes/macrophages into the CNS. GLD is characterized by motor defects, cognitive deficits, seizures, and death by 2–5 years of age. It has been hypothesized that psychosine accumulation, primarily within lipid rafts, results in the pathogenic cascade in GLD. However, the mechanism of psychosine toxicity has yet to be elucidated. Therefore, we synthesized the enantiomer of …


Proposed Coherent Trapping Of A Population Of Electrons In A C60 Molecule Induced By Laser Excitation, Thomas George, G.P. Zhang Nov 2012

Proposed Coherent Trapping Of A Population Of Electrons In A C60 Molecule Induced By Laser Excitation, Thomas George, G.P. Zhang

Chemistry & Biochemistry Faculty Works

This Letter demonstrates the possibility of generating coherent population trapping in C60. Similar to a three-level Λ system, C60 has a forbidden transition between the highest occupied molecular orbital (HOMO) (|a⟩) and the lowest unoccupied molecular orbital (LUMO) (|c⟩), but a dipole-allowed transition between HOMO and LUMO+1 (|b⟩) and between |b⟩ and |c⟩. We employ two cw laser fields, one coupling and one probe. The strong coupling field is switched on first to resonantly excite the transition between |b⟩ and |c⟩. After a delay, the probe is switched on; the coherent interaction between the coupling and probe fields traps the …


2-Allylphenyl Glycosides As Complementary Building Blocks For Oligosaccharide And Glycoconjugate Synthesis, Hemali Premathilake, Alexei Demchenko Apr 2012

2-Allylphenyl Glycosides As Complementary Building Blocks For Oligosaccharide And Glycoconjugate Synthesis, Hemali Premathilake, Alexei Demchenko

Chemistry & Biochemistry Faculty Works

The O-allylphenyl (AP) anomeric moiety was investigated as a new leaving group that can be activated for chemical glycosylation under a variety of conditions, through both direct and remote pathways. Differentiation between the two activation pathways was achieved in a mechanistic study. The orthogonal-type activation of the AP moiety along with common thioglycosides allows for the execution of efficient oligosaccharide assembly.


Isolated Amyloid-Β(1−42) Protofibrils, But Not Isolated Fibrils, Are Robust Stimulators Of Microglia, Geeta Paranjape, Lisa Gouwens, David Osborn, Michael Nichols Apr 2012

Isolated Amyloid-Β(1−42) Protofibrils, But Not Isolated Fibrils, Are Robust Stimulators Of Microglia, Geeta Paranjape, Lisa Gouwens, David Osborn, Michael Nichols

Chemistry & Biochemistry Faculty Works

Senile plaques composed of amyloid-β protein (Aβ) are an unshakable feature of the Alzheimer’s disease (AD) brain. Although there is significant debate on the role of the plaques in AD progression, there is little disagreement on their role in stimulating a robust inflammatory response within the context of the disease. Significant inflammatory markers such as activated microglia and cytokines are observed almost exclusively surrounding the plaques. However, recent evidence suggests that the plaque exterior may contain a measurable level of soluble Aβ aggregates. The observations that microglia activation in vivo is selectively stimulated by distinct Aβ deposits led us to …


Development Of Lps Antagonistic Therapeutics: Synthesis And Evaluation Of Glucopyranoside-Spacer-Amino Acid Motifs, Sophon Kaeothip, Geeta Paranjape, Shana Terrill, Aileen Bongat, Maria Udan, Teerada Kamkhachorn, Hope Johnson, Michael Nichols, Alexei Demchenko Aug 2011

Development Of Lps Antagonistic Therapeutics: Synthesis And Evaluation Of Glucopyranoside-Spacer-Amino Acid Motifs, Sophon Kaeothip, Geeta Paranjape, Shana Terrill, Aileen Bongat, Maria Udan, Teerada Kamkhachorn, Hope Johnson, Michael Nichols, Alexei Demchenko

Chemistry & Biochemistry Faculty Works

No abstract provided.