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Full-Text Articles in Medicinal-Pharmaceutical Chemistry

The Forensic Characterization Of Bacterial And Fungal Organisms In Traditional Chinese Medicine, Julia Grzymkowski, Christopher J. Ehrhardt, Justin L. Poklis, Michelle R. Peace Jan 2018

The Forensic Characterization Of Bacterial And Fungal Organisms In Traditional Chinese Medicine, Julia Grzymkowski, Christopher J. Ehrhardt, Justin L. Poklis, Michelle R. Peace

Undergraduate Research Posters

There has been an increase in use of Traditional Chinese Medicine (TCM) in the United States because they are less expensive and believed to be more effective with less adverse effects in comparison to traditional pharmaceutics. Therefore, sales have increased in the US, despite articles and case studies demonstrating the dangers, such as injury and death, related to TCM, stemming from improper labelling, toxic contaminants, and, in some cases, the presence of pathogenic bacteria. The aim of this study was to perform a survival experiment to demonstrate the importance of proper herbal brewing technique and to conduct a molecular and ...


Design And Synthesis Of Analogs Of Myo-Inositol, Serine, And Cysteine To Enable Chemical Biology Studies, Tanei J. Ricks Dec 2017

Design And Synthesis Of Analogs Of Myo-Inositol, Serine, And Cysteine To Enable Chemical Biology Studies, Tanei J. Ricks

Doctoral Dissertations

Phosphorylated myo-inositol compounds including inositol phosphates (InsPs) as well as the phosphatidylinositol polyphosphate lipids (PIPns) are critical biomolecules that regulate many of the most important biological processes and pathways. They are aberrant in many disease states due to their regulatory function. The same is true of the phospholipid phosphatidylserine (PS) which can serve as a marker to begin apoptosis. However, the full scope of activities of these structures is not clear, particularly since techniques that enable global detection and analysis of the production of these compounds spatially and temporally are lacking. With all of these obstacles in ...


Dengue Virus Ns2b/Ns3 Protease Inhibitors Exploiting The Prime Side, Kuan-Hung Lin, Akbar Ali, Linah Rusere, Djade I. Soumana, Nese Kurt Yilmaz, Celia A. Schiffer Jul 2017

Dengue Virus Ns2b/Ns3 Protease Inhibitors Exploiting The Prime Side, Kuan-Hung Lin, Akbar Ali, Linah Rusere, Djade I. Soumana, Nese Kurt Yilmaz, Celia A. Schiffer

Celia A. Schiffer

The mosquito-transmitted dengue virus (DENV) infects millions of people in tropical and subtropical regions. Maturation of DENV particles requires proper cleavage of the viral polyprotein, including processing of 8 of the 13 substrate cleavage sites by dengue virus NS2B/NS3 protease. With no available direct-acting antiviral targeting DENV, NS2/NS3 protease is a promising target for inhibitor design. Current design efforts focus on the nonprime side of the DENV protease active site, resulting in highly hydrophilic and nonspecific scaffolds. However, the prime side also significantly modulates DENV protease binding affinity, as revealed by engineering the binding loop of aprotinin, a ...


Dengue Virus Ns2b/Ns3 Protease Inhibitors Exploiting The Prime Side, Kuan-Hung Lin, Akbar Ali, Linah Rusere, Djade I. Soumana, Nese Kurt Yilmaz, Celia A. Schiffer Apr 2017

Dengue Virus Ns2b/Ns3 Protease Inhibitors Exploiting The Prime Side, Kuan-Hung Lin, Akbar Ali, Linah Rusere, Djade I. Soumana, Nese Kurt Yilmaz, Celia A. Schiffer

University of Massachusetts Medical School Faculty Publications

The mosquito-transmitted dengue virus (DENV) infects millions of people in tropical and subtropical regions. Maturation of DENV particles requires proper cleavage of the viral polyprotein, including processing of 8 of the 13 substrate cleavage sites by dengue virus NS2B/NS3 protease. With no available direct-acting antiviral targeting DENV, NS2/NS3 protease is a promising target for inhibitor design. Current design efforts focus on the nonprime side of the DENV protease active site, resulting in highly hydrophilic and nonspecific scaffolds. However, the prime side also significantly modulates DENV protease binding affinity, as revealed by engineering the binding loop of aprotinin, a ...


Structure Of The Vif-Binding Domain Of The Antiviral Enzyme Apobec3g, Takahide Kouno, Elizabeth Luengas, Megumi Shigematsu, Shivender Shandilya, Jingying Zhang, Luan Chen, Mayuko Hara, Celia Schiffer, Reuben Harris, Hiroshi Matsuo Jan 2016

Structure Of The Vif-Binding Domain Of The Antiviral Enzyme Apobec3g, Takahide Kouno, Elizabeth Luengas, Megumi Shigematsu, Shivender Shandilya, Jingying Zhang, Luan Chen, Mayuko Hara, Celia Schiffer, Reuben Harris, Hiroshi Matsuo

Celia A. Schiffer

The human APOBEC3G (A3G) DNA cytosine deaminase restricts and hypermutates DNA-based parasites including HIV-1. The viral infectivity factor (Vif) prevents restriction by triggering A3G degradation. Although the structure of the A3G catalytic domain is known, the structure of the N-terminal Vif-binding domain has proven more elusive. Here, we used evolution- and structure-guided mutagenesis to solubilize the Vif-binding domain of A3G, thus permitting structural determination by NMR spectroscopy. A smaller zinc-coordinating pocket and altered helical packing distinguish the structure from previous catalytic-domain structures and help to explain the reported inactivity of this domain. This soluble A3G N-terminal domain is bound by ...


Simultaneously Targeting The Ns3 Protease And Helicase Activities For More Effective Hepatitis C Virus Therapy, Jean Ndjomou, M Corby, Noreena Sweeney, Alicia Hanson, Cihan Aydin, Akbar Ali, Celia Schiffer, Kelin Li, Kevin Frankowski, Frank Schoenen, David Frick Jan 2016

Simultaneously Targeting The Ns3 Protease And Helicase Activities For More Effective Hepatitis C Virus Therapy, Jean Ndjomou, M Corby, Noreena Sweeney, Alicia Hanson, Cihan Aydin, Akbar Ali, Celia Schiffer, Kelin Li, Kevin Frankowski, Frank Schoenen, David Frick

Celia A. Schiffer

This study examines the specificity and mechanism of action of a recently reported hepatitis C virus (HCV) nonstructural protein 3 (NS3) helicase-protease inhibitor (HPI), and the interaction of HPI with the NS3 protease inhibitors telaprevir, boceprevir, danoprevir, and grazoprevir. HPI most effectively reduced cellular levels of subgenomic genotype 4a replicons, followed by genotypes 3a and 1b replicons. HPI had no effect on HCV genotype 2a or dengue virus replicon levels. Resistance evolved more slowly to HPI than telaprevir, and HPI inhibited telaprevir-resistant replicons. Molecular modeling and analysis of the ability of HPI to inhibit peptide hydrolysis catalyzed by a variety ...


Inhibition Of Apobec3g Activity Impedes Double-Stranded Dna Repair, Ponnandy Prabhu, Shivender Shandilya, Elena Britan-Rosich, Adi Nagler, Celia Schiffer, Moshe Kotler Jan 2016

Inhibition Of Apobec3g Activity Impedes Double-Stranded Dna Repair, Ponnandy Prabhu, Shivender Shandilya, Elena Britan-Rosich, Adi Nagler, Celia Schiffer, Moshe Kotler

Celia A. Schiffer

The cellular cytidine deaminase APOBEC3G (A3G) was first described as an anti-HIV-1 restriction factor, acting by directly deaminating reverse transcripts of the viral genome. HIV-1 Vif neutralizes the activity of A3G, primarily by mediating degradation of A3G to establish effective infection in host target cells. Lymphoma cells, which express high amounts of A3G, can restrict Vif-deficient HIV-1. Interestingly, these cells are more stable in the face of treatments that result in double-stranded DNA damage, such as ionizing radiation and chemotherapies. Previously, we showed that the Vif-derived peptide (Vif25-39) efficiently inhibits A3G deamination, and increases the sensitivity of lymphoma cells to ...


Modulation Of Hiv Protease Flexibility By The T80n Mutation, Hao Zhou, Shangyang Li, John Badger, Ellen Nalivaika, Yufeng Cai, Jennifer Foulkes-Murzycki, Celia Schiffer, Lee Makowski Jan 2016

Modulation Of Hiv Protease Flexibility By The T80n Mutation, Hao Zhou, Shangyang Li, John Badger, Ellen Nalivaika, Yufeng Cai, Jennifer Foulkes-Murzycki, Celia Schiffer, Lee Makowski

Celia A. Schiffer

The flexibility of HIV protease (HIVp) plays a critical role in enabling enzymatic activity and is required for substrate access to the active site. While the importance of flexibility in the flaps that cover the active site is well known, flexibility in other parts of the enzyme is also critical for function. One key region is a loop containing Thr 80, which forms the walls of the active site. Although not situated within the active site, amino acid Thr80 is absolutely conserved. The mutation T80N preserves the structure of the enzyme but catalytic activity is completely lost. To investigate the ...


A Direct Interaction With Rna Dramatically Enhances The Catalytic Activity Of The Hiv-1 Protease In Vitro, Marc Potempa, Ellen Nalivaika, Debra Ragland, Sook-Kyung Lee, Celia Schiffer, Ronald Swanstrom Jan 2016

A Direct Interaction With Rna Dramatically Enhances The Catalytic Activity Of The Hiv-1 Protease In Vitro, Marc Potempa, Ellen Nalivaika, Debra Ragland, Sook-Kyung Lee, Celia Schiffer, Ronald Swanstrom

Celia A. Schiffer

Though the steps of human immunodeficiency virus type 1 (HIV-1) virion maturation are well documented, the mechanisms regulating the proteolysis of the Gag and Gag-Pro-Pol polyproteins by the HIV-1 protease (PR) remain obscure. One proposed mechanism argues that the maturation intermediate p15NC must interact with RNA for efficient cleavage by the PR. We investigated this phenomenon and found that processing of multiple substrates by the HIV-1 PR was enhanced in the presence of RNA. The acceleration of proteolysis occurred independently from the substrate's ability to interact with nucleic acid, indicating that a direct interaction between substrate and RNA is ...


A Balance Between Inhibitor Binding And Substrate Processing Confers Influenza Drug Resistance, Li Jiang, Ping Liu, Claudia Bank, Nicholas Renzette, Kristina Prachanronarong, L. Yilmaz, Daniel Caffrey, Konstantin Zeldovich, Celia Schiffer, Timothy Kowalik, Jeffrey Jensen, Robert Finberg, Jennifer Wang, Daniel Bolon Jan 2016

A Balance Between Inhibitor Binding And Substrate Processing Confers Influenza Drug Resistance, Li Jiang, Ping Liu, Claudia Bank, Nicholas Renzette, Kristina Prachanronarong, L. Yilmaz, Daniel Caffrey, Konstantin Zeldovich, Celia Schiffer, Timothy Kowalik, Jeffrey Jensen, Robert Finberg, Jennifer Wang, Daniel Bolon

Celia A. Schiffer

The therapeutic benefits of the neuraminidase (NA) inhibitor oseltamivir are dampened by the emergence of drug resistance mutations in influenza A virus (IAV). To investigate the mechanistic features that underlie resistance, we developed an approach to quantify the effects of all possible single-nucleotide substitutions introduced into important regions of NA. We determined the experimental fitness effects of 450 nucleotide mutations encoding positions both surrounding the active site and at more distant sites in an N1 strain of IAV in the presence and absence of oseltamivir. NA mutations previously known to confer oseltamivir resistance in N1 strains, including H275Y and N295S ...


Structural And Thermodynamic Effects Of Macrocyclization In Hcv Ns3/4a Inhibitor Mk-5172, Djade Soumana, Nese Yilmaz, Kristina Prachanronarong, Cihan Aydin, Akbar Ali, Celia Schiffer Jan 2016

Structural And Thermodynamic Effects Of Macrocyclization In Hcv Ns3/4a Inhibitor Mk-5172, Djade Soumana, Nese Yilmaz, Kristina Prachanronarong, Cihan Aydin, Akbar Ali, Celia Schiffer

Celia A. Schiffer

Recent advances in direct-acting antivirals against Hepatitis C Virus (HCV) have led to the development of potent inhibitors, including MK-5172, that target the viral NS3/4A protease with relatively low susceptibility to resistance. MK-5172 has a P2-P4 macrocycle and a unique binding mode among current protease inhibitors where the P2 quinoxaline packs against the catalytic residues H57 and D81. However, the effect of macrocyclization on this binding mode is not clear, as is the relation between macrocyclization, thermodynamic stabilization, and susceptibility to the resistance mutation A156T. We have determined high-resolution crystal structures of linear and P1-P3 macrocyclic analogs of MK-5172 ...


Colloidal And Biological Properties Of Triscationic Amphiphiles With One Or Two Tails, John N. Marafino Jan 2014

Colloidal And Biological Properties Of Triscationic Amphiphiles With One Or Two Tails, John N. Marafino

Masters Theses

The decline in the development of novel antimicrobials, combined with the misusage and over prescription of antibiotics, has contributed to the increasing prevalence of antimicrobial-resistant infections. Thus development of effective novel disinfectants could reduce the transmission of pathogens and decrease the risk of infection by antibiotic resistant organisms. The antimicrobial activity of amphiphiles, compounds with hydrophobic and hydrophilic regions, was first reported in 1935, and has influenced the synthesis of amphiphiles with variations in structure. In this study, three series of amphiphiles were synthesized by two subsequent Menshutkin reactions. Each amphiphile contains one or two hydrocarbon tails ranging from 8 ...


A Supramolecular Strategy To Assemble Multifunctional Viral Nanoparticles, L. Chen, Xia Zhao, Y. Lin, Y. Huang, Qian Wang Jan 2013

A Supramolecular Strategy To Assemble Multifunctional Viral Nanoparticles, L. Chen, Xia Zhao, Y. Lin, Y. Huang, Qian Wang

Faculty Publications

Using a one-pot approach driven by the supramolecular interaction between β-cyclodextrin and adamantyl moieties, multifunctional viral nanoparticles can be facilely formulated for biomedical applications.


Promise Of Advances In Simulation Methods For Protein Crystallography: Implicit Solvent Models, Time-Averaging Refinement, And Quantum Mechanical Modeling, Celia Schiffer, Jan Hermans Nov 2011

Promise Of Advances In Simulation Methods For Protein Crystallography: Implicit Solvent Models, Time-Averaging Refinement, And Quantum Mechanical Modeling, Celia Schiffer, Jan Hermans

Celia A. Schiffer

No abstract provided.


Competition Between Ski And Creb-Binding Protein For Binding To Smad Proteins In Transforming Growth Factor-Beta Signaling, Weijun Chen, Suvana Lam, Hema Srinath, Celia Schiffer, William Royer, Kai Lin Nov 2011

Competition Between Ski And Creb-Binding Protein For Binding To Smad Proteins In Transforming Growth Factor-Beta Signaling, Weijun Chen, Suvana Lam, Hema Srinath, Celia Schiffer, William Royer, Kai Lin

Celia A. Schiffer

The family of Smad proteins mediates transforming growth factor-beta (TGF-beta) signaling in cell growth and differentiation. Smads repress or activate TGF-beta signaling by interacting with corepressors (e.g. Ski) or coactivators (e.g. CREB-binding protein (CBP)), respectively. Specifically, Ski has been shown to interfere with the interaction between Smad3 and CBP. However, it is unclear whether Ski competes with CBP for binding to Smads and whether they can interact with Smad3 at the same binding surface on Smad3. We investigated the interactions among purified constructs of Smad, Ski, and CBP in vitro by size-exclusion chromatography, isothermal titration calorimetry, and mutational ...


Viral Protease Inhibitors, Jeffrey Anderson, Celia Schiffer, Sook-Kyung Lee, Ronald Swanstrom Nov 2011

Viral Protease Inhibitors, Jeffrey Anderson, Celia Schiffer, Sook-Kyung Lee, Ronald Swanstrom

Celia A. Schiffer

This review provides an overview of the development of viral protease inhibitors as antiviral drugs. We concentrate on HIV-1 protease inhibitors, as these have made the most significant advances in the recent past. Thus, we discuss the biochemistry of HIV-1 protease, inhibitor development, clinical use of inhibitors, and evolution of resistance. Since many different viruses encode essential proteases, it is possible to envision the development of a potent protease inhibitor for other viruses if the processing site sequence and the catalytic mechanism are known. At this time, interest in developing inhibitors is limited to viruses that cause chronic disease, viruses ...


Mutation Patterns And Structural Correlates In Human Immunodeficiency Virus Type 1 Protease Following Different Protease Inhibitor Treatments, Thomas Wu, Celia Schiffer, Matthew Gonzales, Jonathan Taylor, Rami Kantor, Sunwen Chou, Dennis Israelski, Andrew Zolopa, W. Jeffrey Fessel, Robert Shafer Nov 2011

Mutation Patterns And Structural Correlates In Human Immunodeficiency Virus Type 1 Protease Following Different Protease Inhibitor Treatments, Thomas Wu, Celia Schiffer, Matthew Gonzales, Jonathan Taylor, Rami Kantor, Sunwen Chou, Dennis Israelski, Andrew Zolopa, W. Jeffrey Fessel, Robert Shafer

Celia A. Schiffer

Although many human immunodeficiency virus type 1 (HIV-1)-infected persons are treated with multiple protease inhibitors in combination or in succession, mutation patterns of protease isolates from these persons have not been characterized. We collected and analyzed 2,244 subtype B HIV-1 isolates from 1,919 persons with different protease inhibitor experiences: 1,004 isolates from untreated persons, 637 isolates from persons who received one protease inhibitor, and 603 isolates from persons receiving two or more protease inhibitors. The median number of protease mutations per isolate increased from 4 in untreated persons to 12 in persons who had received four ...


Curling Of Flap Tips In Hiv-1 Protease As A Mechanism For Substrate Entry And Tolerance Of Drug Resistance, Walter Scott, Celia Schiffer Nov 2011

Curling Of Flap Tips In Hiv-1 Protease As A Mechanism For Substrate Entry And Tolerance Of Drug Resistance, Walter Scott, Celia Schiffer

Celia A. Schiffer

BACKGROUND: The human immunodeficiency virus type 1 (HIV-1) protease is an essential viral protein that is a major drug target in the fight against Acquired Immune Deficiency Syndrome (AIDS). Access to the active site of this homodimeric enzyme is gained when two large flaps, one from each monomer, open. The flap movements are therefore central to the function of the enzyme, yet determining how these flaps move at an atomic level has not been experimentally possible.

RESULTS: In the present study, we observe the flaps of HIV-1 protease completely opening during a 10 ns solvated molecular dynamics simulation starting from ...


Resilience To Resistance Of Hiv-1 Protease Inhibitors: Profile Of Darunavir, Eric Lefebvre, Celia A. Schiffer Nov 2011

Resilience To Resistance Of Hiv-1 Protease Inhibitors: Profile Of Darunavir, Eric Lefebvre, Celia A. Schiffer

Celia A. Schiffer

The current effectiveness of HAART in the management of HIV infection is compromised by the emergence of extensively cross-resistant strains of HIV-1, requiring a significant need for new therapeutic agents. Due to its crucial role in viral maturation and therefore HIV-1 replication and infectivity, the HIV-1 protease continues to be a major development target for antiretroviral therapy. However, new protease inhibitors must have higher thresholds to the development of resistance and cross-resistance. Research has demonstrated that the binding characteristics between a protease inhibitor and the active site of the HIV-1 protease are key factors in the development of resistance. More ...


Structural Analysis Of Human Immunodeficiency Virus Type 1 Crf01_Ae Protease In Complex With The Substrate P1-P6., Rajintha Bandaranayake, Moses Prabu-Jeyabalan, Junko Kakizawa, Wataru Sugiura, Celia Schiffer Nov 2011

Structural Analysis Of Human Immunodeficiency Virus Type 1 Crf01_Ae Protease In Complex With The Substrate P1-P6., Rajintha Bandaranayake, Moses Prabu-Jeyabalan, Junko Kakizawa, Wataru Sugiura, Celia Schiffer

Celia A. Schiffer

The effect of amino acid variability between human immunodeficiency virus type 1 (HIV-1) clades on structure and the emergence of resistance mutations in HIV-1 protease has become an area of significant interest in recent years. We determined the first crystal structure of the HIV-1 CRF01_AE protease in complex with the p1-p6 substrate to a resolution of 2.8 A. Hydrogen bonding between the flap hinge and the protease core regions shows significant structural rearrangements in CRF01_AE protease compared to the clade B protease structure.


Investigation Of Protein Unfolding And Stability By Computer Simulation, Wilfred Van Gunsteren, P. Hunenberger, H. Kovacs, A. Mark, Celia Schiffer Nov 2011

Investigation Of Protein Unfolding And Stability By Computer Simulation, Wilfred Van Gunsteren, P. Hunenberger, H. Kovacs, A. Mark, Celia Schiffer

Celia A. Schiffer

Structural, dynamic and energetic properties of proteins in solution can be studied in atomic detail by molecular dynamics computer simulation. Protein unfolding can be caused by a variety of driving forces induced in different ways: increased temperature or pressure, change of solvent composition, or protein amino acid mutation. The stability and unfolding of four different proteins (bovine pancreatic trypsin inhibitor, hen egg white lysozyme, the surfactant protein C and the DNA-binding domain of the 434 repressor) have been studied by applying the afore-mentioned driving forces and also to some artificial forces. The results give a picture of protein (in)stability ...


Hypericum In Infection: Identification Of Anti-Viral And Anti-Inflammatory Constituents, Diane F. Birt, Mark P. Widrlechner, Kimberly D.P. Hammer, Matthew L. Hillwig, Jingqiang Wei, George A. Kraus, Patricia A. Murphy, Joe-Ann Mccoy, Eve S. Wurtele, Jeffrey D. Neighbors, David F. Wiemer, Wendy J. Maury, Jason P. Price Aug 2009

Hypericum In Infection: Identification Of Anti-Viral And Anti-Inflammatory Constituents, Diane F. Birt, Mark P. Widrlechner, Kimberly D.P. Hammer, Matthew L. Hillwig, Jingqiang Wei, George A. Kraus, Patricia A. Murphy, Joe-Ann Mccoy, Eve S. Wurtele, Jeffrey D. Neighbors, David F. Wiemer, Wendy J. Maury, Jason P. Price

Food Science and Human Nutrition Publications

The Iowa Center for Research on Botanical Dietary Supplements seeks to optimize Echinacea, Hypericum, and Prunella botanical supplements for human-health benefit, emphasizing anti-viral, anti-inflammatory, and anti-pain activities. This mini-review reports on ongoing studies on Hypericum. The Center uses the genetically diverse, well-documented Hypericum populations collected and maintained at the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS), and the strength of research in synthetic chemistry at Iowa State University to tap natural diversity, to help discover key constituents and interactions among constituents that impact bioactivity and toxicity. The NCRPIS has acquired more than 180 distinct populations of Hypericum, with a ...


Controlled Assembly Of Rodlike Viruses With Polymers, T. Li, L. Wu, N. Suthiwangcharoen, M. A. Bruckman, D. Cash, J. S. Hudson, Soumitra Ghoshroy, Qian Wang Jan 2009

Controlled Assembly Of Rodlike Viruses With Polymers, T. Li, L. Wu, N. Suthiwangcharoen, M. A. Bruckman, D. Cash, J. S. Hudson, Soumitra Ghoshroy, Qian Wang

Faculty Publications

A practical method to assemble rodlike tobacco mosaic virus and bacteriophage M13 with polymers was developed, which afforded a 3D core–shell composite with morphological control.


Oriented Cell Growth On Self-Assembled Bacteriophage M13 Thin Films, J. Rong, L. A. Lee, K. Li, B. Harp, C. M. Mello, Z. Niu, Qian Wang Jan 2008

Oriented Cell Growth On Self-Assembled Bacteriophage M13 Thin Films, J. Rong, L. A. Lee, K. Li, B. Harp, C. M. Mello, Z. Niu, Qian Wang

Faculty Publications

Fibrillar M13 bacteriophages were used as basic building blocks to generate thin films with aligned nanogrooves, which, upon chemical grafting with RGD peptides, guide cell alignment and orient the cell outgrowth along defined directions.