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Full-Text Articles in Medicinal-Pharmaceutical Chemistry

Mechanism For Apobec3g Catalytic Exclusion Of Rna And Non-Substrate Dna, William C. Solomon, Wazo Myint, Shurong Hou, Tapan Kanai, Rashmi Tripathi, Nese Kurt Yilmaz, Celia A. Schiffer, Hiroshi Matsuo Aug 2019

Mechanism For Apobec3g Catalytic Exclusion Of Rna And Non-Substrate Dna, William C. Solomon, Wazo Myint, Shurong Hou, Tapan Kanai, Rashmi Tripathi, Nese Kurt Yilmaz, Celia A. Schiffer, Hiroshi Matsuo

Schiffer Lab Publications

The potent antiretroviral protein APOBEC3G (A3G) specifically targets and deaminates deoxycytidine nucleotides, generating deoxyuridine, in single stranded DNA (ssDNA) intermediates produced during HIV replication. A non-catalytic domain in A3G binds strongly to RNA, an interaction crucial for recruitment of A3G to the virion; yet, A3G displays no deamination activity for cytidines in viral RNA. Here, we report NMR and molecular dynamics (MD) simulation analysis for interactions between A3Gctd and multiple substrate or non-substrate DNA and RNA, in combination with deamination assays. NMR ssDNA-binding experiments revealed that the interaction with residues in helix1 and loop1 (T201-L220) distinguishes the binding mode of ...


Molecular And Structural Mechanism Of Pan-Genotypic Hcv Ns3/4a Protease Inhibition By Glecaprevir, Jennifer Timm, Klajdi Kosovrasti, Mina Henes, Florian Leidner, Shurong Hou, Akbar Ali, Nese Kurt Yilmaz, Celia A. Schiffer Jul 2019

Molecular And Structural Mechanism Of Pan-Genotypic Hcv Ns3/4a Protease Inhibition By Glecaprevir, Jennifer Timm, Klajdi Kosovrasti, Mina Henes, Florian Leidner, Shurong Hou, Akbar Ali, Nese Kurt Yilmaz, Celia A. Schiffer

University of Massachusetts Medical School Faculty Publications

Hepatitis C virus (HCV), causative agent of chronic viral hepatitis, infects 71 million people worldwide and is divided into seven genotypes and multiple subtypes with sequence identities between 68 to 82%. While older generation direct-acting antivirals (DAAs) had varying effectiveness against different genotypes, the newest NS3/4A protease inhibitors including glecaprevir (GLE) have pan-genotypic activity. The structural basis for pan-genotypic inhibition and effects of polymorphisms on inhibitor potency were not well known due to lack of crystal structures of GLE-bound NS3/4A or genotypes other than 1. In this study, we determined the crystal structures of NS3/4A from genotypes ...


Thioredoxin Modulates Protein Arginine Deiminase 4 (Pad4)-Catalyzed Citrullination, Mitesh Nagar, Ronak Tilvawala, Paul R. Thompson Feb 2019

Thioredoxin Modulates Protein Arginine Deiminase 4 (Pad4)-Catalyzed Citrullination, Mitesh Nagar, Ronak Tilvawala, Paul R. Thompson

Open Access Articles

Protein citrullination is a post-translational modification catalyzed by the protein arginine deiminases (PADs). This modification plays a crucial role in the pathophysiology of numerous autoimmune disorders including RA. Recently, there has been a growing interest in investigating physiological regulators of PAD activity to understand the primary cause of the associated disorders. Apart from calcium, it is well-documented that a reducing environment activates the PADs. Although the concentration of thioredoxin (hTRX), an oxidoreductase that maintains the cellular reducing environment, is elevated in RA patients, its contribution toward RA progression or PAD activity has not been explored. Herein, we demonstrate that hTRX ...


Peptidylarginine Deiminases 2 And 4 Modulate Innate And Adaptive Immune Responses In Tlr-7-Dependent Lupus., Yudong Liu, Yaíma L Lightfoot, Nickie Seto, Santanu Mondal, Padmavathy Nandha Premnath, Paul R. Thompson Dec 2018

Peptidylarginine Deiminases 2 And 4 Modulate Innate And Adaptive Immune Responses In Tlr-7-Dependent Lupus., Yudong Liu, Yaíma L Lightfoot, Nickie Seto, Santanu Mondal, Padmavathy Nandha Premnath, Paul R. Thompson

University of Massachusetts Medical School Publications

The peptidylarginine deiminases PAD2 and PAD4 are implicated in the pathogenesis of several autoimmune diseases. PAD4 may be pathogenic in systemic lupus erythematosus (SLE) through its role in neutrophil extracellular trap (NET) formation that promotes autoantigen externalization, immune dysregulation, and organ damage. The role of this enzyme in mouse models of autoimmunity remains unclear, as pan-PAD chemical inhibitors improve clinical phenotype, whereas PAD4-KO models have given conflicting results. The role of PAD2 in SLE has not been investigated. The differential roles of PAD2 and PAD4 in TLR-7-dependent lupus autoimmunity were examined. Padi4-/- displayed decreased autoantibodies, type I IFN responses, immune ...


Functional Features Defining The Efficacy Of Cholesterol-Conjugated, Self-Deliverable, Chemically Modified Sirnas, Taisia Shmushkovich, Kathryn R. Monopoli, Diana Homsy, Dmitriy Leyfer, Monica Betancur-Boissel, Anastasia Khvorova, Alexey D. Wolfson Nov 2018

Functional Features Defining The Efficacy Of Cholesterol-Conjugated, Self-Deliverable, Chemically Modified Sirnas, Taisia Shmushkovich, Kathryn R. Monopoli, Diana Homsy, Dmitriy Leyfer, Monica Betancur-Boissel, Anastasia Khvorova, Alexey D. Wolfson

Open Access Articles

Progress in oligonucleotide chemistry has produced a shift in the nature of siRNA used, from formulated, minimally modified siRNAs, to unformulated, heavily modified siRNA conjugates. The introduction of extensive chemical modifications is essential for conjugate-mediated delivery. Modifications have a significant impact on siRNA efficacy through interference with recognition and processing by RNAi enzymatic machinery, severely restricting the sequence space available for siRNA design. Many algorithms available publicly can successfully predict the activity of non-modified siRNAs, but the efficiency of the algorithms for designing heavily modified siRNAs has never been systematically evaluated experimentally. Here we screened 356 cholesterol-conjugated siRNAs with extensive ...


Drug Resistance Mutation L76v Alters Nonpolar Interactions At The Flap-Core Interface Of Hiv-1 Protease, Andres Wong-Sam, Yuan-Fang Wang, Ying Zhang, Arun K. Ghosh, Robert W. Harrison, Irene T. Weber Sep 2018

Drug Resistance Mutation L76v Alters Nonpolar Interactions At The Flap-Core Interface Of Hiv-1 Protease, Andres Wong-Sam, Yuan-Fang Wang, Ying Zhang, Arun K. Ghosh, Robert W. Harrison, Irene T. Weber

RNA Therapeutics Institute Publications

Four HIV-1 protease (PR) inhibitors, clinical inhibitors lopinavir and tipranavir, and two investigational compounds 4 and 5, were studied for their effect on the structure and activity of PR with drug-resistant mutation L76V (PRL76V). Compound 5 exhibited the best K i value of 1.9 nM for PRL76V, whereas the other three inhibitors had K i values of 4.5-7.6 nM, 2-3 orders of magnitude worse than for wild-type enzymes. Crystal structures showed only minor differences in interactions of inhibitors with PRL76V compared to wild-type complexes. The shorter side chain of Val76 in the mutant lost hydrophobic interactions with ...


Histone Citrullination Represses Mirna Expression Resulting In Increased Oncogene Mrnas In Somatolactotrope Cells., Stanley B Devore, Coleman H. Young, Guangyuan Li, Anitha Sundararajan, Thiruvarangan Ramaraj, Joann Mudge, Faye Schilkey, Aaron Muth, Paul R. Thompson, Brian D. Cherrington Sep 2018

Histone Citrullination Represses Mirna Expression Resulting In Increased Oncogene Mrnas In Somatolactotrope Cells., Stanley B Devore, Coleman H. Young, Guangyuan Li, Anitha Sundararajan, Thiruvarangan Ramaraj, Joann Mudge, Faye Schilkey, Aaron Muth, Paul R. Thompson, Brian D. Cherrington

University of Massachusetts Medical School Publications

Peptidylarginine deiminase (PAD) enzymes convert histone arginine residues into citrulline to modulate chromatin organization and gene expression. Although PADs are expressed in anterior pituitary gland cells, their functional role and expression in pituitary adenomas is unknown. To begin to address these questions, we first examined normal human pituitaries and pituitary adenomas and found that PAD2, PAD4 and citrullinated histones are highest in prolactinomas and somatoprolactinomas. In the somatoprolactinoma-derived GH3 cell line, PADs citrullinate histone H3, which is attenuated by a pan-PAD inhibitor. RNA-sequencing and ChIP studies show that the expression of microRNAs let-7c-2, miR-23b and miR-29c is suppressed by histone ...


T Cell Epitope Engineering: An Avian H7n9 Influenza Vaccine Strategy For Pandemic Preparedness And Response, Leonard Moise, Bethany M. Biron, Christine M. Boyle, Nese Kurt Yilmaz, Hyesun Jang, Celia A. Schiffer, Ted M. Ross, William D. Martin, Anne S. De Groot Sep 2018

T Cell Epitope Engineering: An Avian H7n9 Influenza Vaccine Strategy For Pandemic Preparedness And Response, Leonard Moise, Bethany M. Biron, Christine M. Boyle, Nese Kurt Yilmaz, Hyesun Jang, Celia A. Schiffer, Ted M. Ross, William D. Martin, Anne S. De Groot

Schiffer Lab Publications

The delayed availability of vaccine during the 2009 H1N1 influenza pandemic created a sense of urgency to better prepare for the next influenza pandemic. Advancements in manufacturing technology, speed and capacity have been achieved but vaccine effectiveness remains a significant challenge. Here, we describe a novel vaccine design strategy called immune engineering in the context of H7N9 influenza vaccine development. The approach combines immunoinformatic and structure modeling methods to promote protective antibody responses against H7N9 hemagglutinin (HA) by engineering whole antigens to carry seasonal influenza HA memory CD4(+) T cell epitopes - without perturbing native antigen structure - by galvanizing HA-specific memory ...


Modulating Viscoelasticity, Stiffness, And Degradation Of Synthetic Cellular Niches Via Stoichiometric Tuning Of Covalent Versus Dynamic Noncovalent Cross-Linking, Yu Tan, Henry Huang, David C. Ayers, Jie Song Aug 2018

Modulating Viscoelasticity, Stiffness, And Degradation Of Synthetic Cellular Niches Via Stoichiometric Tuning Of Covalent Versus Dynamic Noncovalent Cross-Linking, Yu Tan, Henry Huang, David C. Ayers, Jie Song

Open Access Articles

Viscoelasticity, stiffness, and degradation of tissue matrices regulate cell behavior, yet predictive synergistic tuning of these properties in synthetic cellular niches remains elusive. We hypothesize that reversible physical cross-linking can be quantitatively introduced to synthetic hydrogels to accelerate stress relaxation and enhance network stiffness, while strategic placement of isolated labile linkages near cross-linking sites can predict hydrogel degradation, both of which are essential for creating adaptive cellular niches. To test these hypotheses, chondrocytes were encapsulated in hydrogels formed by biorthogonal covalent and noncovalent physical cross-linking of a pair of hydrophilic building blocks. The stiffer and more viscoelastic hydrogels with DBCO-DBCO ...


Citrullination Inactivates Nicotinamide-N-Methyltransferase, Venkatesh V. Nemmara, Ronak Tilvawala, Ari J. Salinger, Lacey Miller, Son Hong Nguyen, Eranthie Weerapana, Paul R. Thompson Jul 2018

Citrullination Inactivates Nicotinamide-N-Methyltransferase, Venkatesh V. Nemmara, Ronak Tilvawala, Ari J. Salinger, Lacey Miller, Son Hong Nguyen, Eranthie Weerapana, Paul R. Thompson

Thompson Lab Publications

Nicotinamide-N-methyl transferase (NNMT) catalyzes the irreversible methylation of nicotinamide (NAM) to form N-methyl nicotinamide (MeNAM) using SAM as a methyl donor. NNMT is implicated in several chronic disease conditions, including cancers, kidney disease, cardiovascular disease, and Parkinson's disease. Although phosphorylation of NNMT in gastric tumors is reported, the functional effects of this post-translational modification has not been investigated. We previously reported that citrullination of NNMT by Protein Arginine Deiminases (PADs) abolished its methyltransferase activity. Herein, we investigate the mechanism of inactivation. Using tandem MS, we identified three sites of citrullination in NNMT. With this information in hand, we used ...


Assembly Of Human C-Terminal Binding Protein (Ctbp) Into Tetramers, Andrew G. Bellesis, Anne M. Jecrois, Janelle A. Hayes, Celia A. Schiffer, William E. Royer Jun 2018

Assembly Of Human C-Terminal Binding Protein (Ctbp) Into Tetramers, Andrew G. Bellesis, Anne M. Jecrois, Janelle A. Hayes, Celia A. Schiffer, William E. Royer

Schiffer Lab Publications

C-terminal binding protein 1 (CtBP1) and CtBP2 are transcriptional coregulators that repress numerous cellular processes, such as apoptosis, by binding transcription factors and recruiting chromatin-remodeling enzymes to gene promoters. The NAD(H)-linked oligomerization of human CtBP is coupled to its co-transcriptional activity, which is implicated in cancer progression. However, the biologically relevant level of CtBP assembly has not been firmly established; nor has the stereochemical arrangement of the subunits above that of a dimer. Here, multi-angle light scattering (MALS) data established the NAD(+)- and NADH-dependent assembly of CtBP1 and CtBP2 into tetramers. An examination of subunit interactions within CtBP1 ...


Photochemical Control Of Protein Arginine Deiminase (Pad) Activity, Santanu Mondal, Sangram S. Parelkar, Mitesh Nagar, Paul R. Thompson Apr 2018

Photochemical Control Of Protein Arginine Deiminase (Pad) Activity, Santanu Mondal, Sangram S. Parelkar, Mitesh Nagar, Paul R. Thompson

Thompson Lab Publications

Protein Arginine deiminases (PADs) play an important role in the pathogenesis of various diseases, including rheumatoid arthritis, multiple sclerosis, lupus, ulcerative colitis and breast cancer. Therefore, the development of PAD-inhibitors has drawn significant research interest in recent years. Herein, we describe the development of the first photoswitchable PAD-inhibitors. These compounds possess an azobenzene photoswitch to optically control PAD activity. Screening of a series of inhibitors structurally similar to BB-Cl-Amidine afforded compounds 1 and 2 as the most promising candidates for the light-controlled inhibition of PAD2; the cis-isomer of 1 is 10-fold more potent than its trans-isomer, whereas the trans-isomer of ...


Donated Chemical Probes For Open Science, Susanne Muller, Paul R. Thompson, Anke Mueller-Fahrnow Apr 2018

Donated Chemical Probes For Open Science, Susanne Muller, Paul R. Thompson, Anke Mueller-Fahrnow

Open Access Articles

Potent, selective and broadly characterized small molecule modulators of protein function (chemical probes) are powerful research reagents. The pharmaceutical industry has generated many high-quality chemical probes and several of these have been made available to academia. However, probe-associated data and control compounds, such as inactive structurally related molecules and their associated data, are generally not accessible. The lack of data and guidance makes it difficult for researchers to decide which chemical tools to choose. Several pharmaceutical companies (AbbVie, Bayer, Boehringer Ingelheim, Janssen, MSD, Pfizer, and Takeda) have therefore entered into a pre-competitive collaboration to make available a large number of ...


The Development Of Benzimidazole-Based Clickable Probes For The Efficient Labeling Of Cellular Protein Arginine Deiminases (Pads), Venkatesh V. Nemmara, Venkataraman Subramanian, Aaron Muth, Santanu Mondal, Ari J. Salinger, Aaron J. Maurais, Ronak Tilvawala, Eranthie Weerapana, Paul R. Thompson Mar 2018

The Development Of Benzimidazole-Based Clickable Probes For The Efficient Labeling Of Cellular Protein Arginine Deiminases (Pads), Venkatesh V. Nemmara, Venkataraman Subramanian, Aaron Muth, Santanu Mondal, Ari J. Salinger, Aaron J. Maurais, Ronak Tilvawala, Eranthie Weerapana, Paul R. Thompson

Thompson Lab Publications

Citrullination is the post-translational hydrolysis of peptidyl-arginines to form peptidyl-citrulline, a reaction that is catalyzed by the protein arginine deiminases (PADs), a family of calcium-regulated enzymes. Aberrantly increased protein citrullination is associated with a slew of autoimmune diseases (e.g., rheumatoid arthritis (RA), multiple sclerosis, lupus, and ulcerative colitis) and certain cancers. Given the clear link between increased PAD activity and human disease, the PADs are therapeutically relevant targets. Herein, we report the development of next generation cell permeable and "clickable" probes (BB-Cl-Yne and BB-F-Yne) for covalent labeling of the PADs both in vitro and in cell-based systems. Using advanced ...


Comparison Of Partially And Fully Chemically-Modified Sirna In Conjugate-Mediated Delivery In Vivo, Matthew R. Hassler, Anton A. Turanov, Julia F. Alterman, Reka A. Haraszti, Andrew H. Coles, Maire F. Osborn, Dimas Echeverria, Mehran Nikan, William E. Salomon, Loic Roux, Bruno M. D. C. Godinho, Sarah M. Davis, David V. Morrissey, Phillip D. Zamore, S. Ananth Karumanchi, Melissa J. Moore, Neil Aronin, Anastasia Khvorova Feb 2018

Comparison Of Partially And Fully Chemically-Modified Sirna In Conjugate-Mediated Delivery In Vivo, Matthew R. Hassler, Anton A. Turanov, Julia F. Alterman, Reka A. Haraszti, Andrew H. Coles, Maire F. Osborn, Dimas Echeverria, Mehran Nikan, William E. Salomon, Loic Roux, Bruno M. D. C. Godinho, Sarah M. Davis, David V. Morrissey, Phillip D. Zamore, S. Ananth Karumanchi, Melissa J. Moore, Neil Aronin, Anastasia Khvorova

Open Access Articles

Small interfering RNA (siRNA)-based drugs require chemical modifications or formulation to promote stability, minimize innate immunity, and enable delivery to target tissues. Partially modified siRNAs (up to 70% of the nucleotides) provide significant stabilization in vitro and are commercially available; thus are commonly used to evaluate efficacy of bio-conjugates for in vivo delivery. In contrast, most clinically-advanced non-formulated compounds, using conjugation as a delivery strategy, are fully chemically modified (100% of nucleotides). Here, we compare partially and fully chemically modified siRNAs in conjugate mediated delivery. We show that fully modified siRNAs are retained at 100x greater levels in various ...


Structural Determination Of The Broadly Reactive Anti-Ighv1-69 Anti-Idiotypic Antibody G6 And Its Idiotope, Yuval Avnir, Kristina L. Prachanronarong, Shurong Hou, Brendan J. Hilbert, Markus-Frederik Bohn, Timothy F. Kowalik, Robert W. Finberg, Jennifer P. Wang, Nese Kurt Yilmaz, Celia A. Schiffer, Wayne A. Marasco Dec 2017

Structural Determination Of The Broadly Reactive Anti-Ighv1-69 Anti-Idiotypic Antibody G6 And Its Idiotope, Yuval Avnir, Kristina L. Prachanronarong, Shurong Hou, Brendan J. Hilbert, Markus-Frederik Bohn, Timothy F. Kowalik, Robert W. Finberg, Jennifer P. Wang, Nese Kurt Yilmaz, Celia A. Schiffer, Wayne A. Marasco

Schiffer Lab Publications

The heavy chain IGHV1-69 germline gene exhibits a high level of polymorphism and shows biased use in protective antibody (Ab) responses to infections and vaccines. It is also highly expressed in several B cell malignancies and autoimmune diseases. G6 is an anti-idiotypic monoclonal Ab that selectively binds to IGHV1-69 heavy chain germline gene 51p1 alleles that have been implicated in these Ab responses and disease processes. Here, we determine the co-crystal structure of humanized G6 (hG6.3) in complex with anti-influenza hemagglutinin stem-directed broadly neutralizing Ab D80. The core of the hG6.3 idiotope is a continuous string of CDR-H2 ...


Selective Targeting Of Bromodomains Of The Bromodomain-Phd Fingers Family Impairs Osteoclast Differentiation, Julia C. Meier, Hanna Witwicka, Sung-Yong Hwang, Mark J. Birnbaum, Stefan Knapp Oct 2017

Selective Targeting Of Bromodomains Of The Bromodomain-Phd Fingers Family Impairs Osteoclast Differentiation, Julia C. Meier, Hanna Witwicka, Sung-Yong Hwang, Mark J. Birnbaum, Stefan Knapp

Open Access Articles

Histone acetyltransferases of the MYST family are recruited to chromatin by BRPF scaffolding proteins. We explored functional consequences and the therapeutic potential of inhibitors targeting acetyl-lysine dependent protein interaction domains (bromodomains) present in BRPF1-3 in bone maintenance. We report three potent and selective inhibitors: one (PFI-4) with high selectivity for the BRPF1B isoform and two pan-BRPF bromodomain inhibitors (OF-1, NI-57). The developed inhibitors displaced BRPF bromodomains from chromatin and did not inhibit cell growth and proliferation. Intriguingly, the inhibitors impaired RANKL-induced differentiation of primary murine bone marrow cells and human primary monocytes into bone resorbing osteoclasts by specifically repressing transcriptional ...


Diverse Stimuli Engage Different Neutrophil Extracellular Trap Pathways, Elaine F. Kenny, Alf Herzig, Renate Krüger, Aaron Muth, Santanu Mondal, Paul R. Thompson, Volker Brinkmann, Horst Von Bernuth, Arturo Zychlinsky Jun 2017

Diverse Stimuli Engage Different Neutrophil Extracellular Trap Pathways, Elaine F. Kenny, Alf Herzig, Renate Krüger, Aaron Muth, Santanu Mondal, Paul R. Thompson, Volker Brinkmann, Horst Von Bernuth, Arturo Zychlinsky

Thompson Lab Publications

Neutrophils release neutrophil extracellular traps (NETs) which ensnare pathogens and have pathogenic functions in diverse diseases. We examined the NETosis pathways induced by five stimuli; PMA, the calcium ionophore A23187, nigericin, Candida albicans and Group B Streptococcus. We studied NET production in neutrophils from healthy donors with inhibitors of molecules crucial to PMA induced NETs including protein kinase C, calcium, reactive oxygen species, the enzymes myeloperoxidase (MPO) and neutrophil elastase. Additionally, neutrophils from chronic granulomatous disease patients, carrying mutations in the NADPH oxidase complex or a MPO-deficient patient were examined. We show that PMA, C. albicans and GBS use a ...


Role Of Peptidylarginine Deiminase 2 (Pad2) In Mammary Carcinoma Cell Migration, Sachi Horibata, Katherine E. Rogers, David Sadegh, Lynne J. Anguish, John L. Mcelwee, Pragya Shah, Paul R. Thompson, Scott A. Coonrod May 2017

Role Of Peptidylarginine Deiminase 2 (Pad2) In Mammary Carcinoma Cell Migration, Sachi Horibata, Katherine E. Rogers, David Sadegh, Lynne J. Anguish, John L. Mcelwee, Pragya Shah, Paul R. Thompson, Scott A. Coonrod

Thompson Lab Publications

BACKGROUND: Penetration of the mammary gland basement membrane by cancer cells is a crucial first step in tumor invasion. Using a mouse model of ductal carcinoma in situ, we previously found that inhibition of peptidylarginine deiminase 2 (PAD2, aka PADI2) activity appears to maintain basement membrane integrity in xenograft tumors. The goal of this investigation was to gain insight into the mechanisms by which PAD2 mediates this process.

METHODS: For our study, we modulated PAD2 activity in mammary ductal carcinoma cells by lentiviral shRNA-mediated depletion, lentiviral-mediated PAD2 overexpression, or PAD inhibition and explored the effects of these treatments on changes ...


A Novel Bromodomain And Extra-Terminal Domain Inhibitors (Beti) That Reverses Hiv-1 Latency, Shuai Liu, Maxime Jean, Wei Zhang, Jian Zhu May 2017

A Novel Bromodomain And Extra-Terminal Domain Inhibitors (Beti) That Reverses Hiv-1 Latency, Shuai Liu, Maxime Jean, Wei Zhang, Jian Zhu

UMass Center for Clinical and Translational Science Research Retreat

Although combinatory antiretroviral therapy (cART) is effective to reduce HIV-1 viremia, it does not eliminate HIV-1 infection. HIV-1 remains latent with the presence of cART, impeding the cure of AIDS. Recently, latency-reversing agents (LRAs) have been developed to purge latent HIV-1, providing an intriguing strategy for eradication of residual, latent viral reservoirs. Our earlier studies show that antagonism of HIV-1 competitive factor bromodomain containing 4 (BRD4) using bromodomain and extra-terminal domain inhibitor (BETi) JQ1 may facilitate the reversal of HIV-1 latency. BETis have recently emerged as a class of compounds that are promising for both the anticancer and HIV-1 latency-reversing ...


Interdependence Of Inhibitor Recognition In Hiv-1 Protease, Janet L. Paulsen, Florian Leidner, Debra A. Ragland, Nese Kurt Yilmaz, Celia A. Schiffer May 2017

Interdependence Of Inhibitor Recognition In Hiv-1 Protease, Janet L. Paulsen, Florian Leidner, Debra A. Ragland, Nese Kurt Yilmaz, Celia A. Schiffer

University of Massachusetts Medical School Faculty Publications

Molecular recognition is a highly interdependent process. Subsite couplings within the active site of proteases are most often revealed through conditional amino acid preferences in substrate recognition. However, the potential effect of these couplings on inhibition and thus inhibitor design is largely unexplored. The present study examines the interdependency of subsites in HIV-1 protease using a focused library of protease inhibitors, to aid in future inhibitor design. Previously a series of darunavir (DRV) analogs was designed to systematically probe the S1' and S2' subsites. Co-crystal structures of these analogs with HIV-1 protease provide the ideal opportunity to probe subsite interdependency ...


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 ...


Peptidylarginine Deiminase 1-Catalyzed Histone Citrullination Is Essential For Early Embryo Development, Xiaoqian Zhang, Xiaoqiu Liu, Mei Zhang, Tingting Li, Aaron Muth, Paul R. Thompson, Scott A. Coonrod, Xuesen Zhang Dec 2016

Peptidylarginine Deiminase 1-Catalyzed Histone Citrullination Is Essential For Early Embryo Development, Xiaoqian Zhang, Xiaoqiu Liu, Mei Zhang, Tingting Li, Aaron Muth, Paul R. Thompson, Scott A. Coonrod, Xuesen Zhang

Thompson Lab Publications

Peptidylarginine deiminase (PADI) enzymes are increasingly being associated with the regulation of chromatin structure and gene activity via histone citrullination. As one of the PADI family members, PADI1 has been mainly reported to be expressed in the epidermis and uterus, where the protein in keratinocytes is thought to promote differentiation by citrullinating filament proteins. However, the roles of PADI1 in preimplantation development have not been addressed. Using a PADI1-specific inhibitor and Padi1-morpholino knockdown, we found that citrullination of histone tails at H4R3 and H3R2/8/17 were markedly reduced in the 2- and 4-cell embryos. Consistent with this observation, early ...


Abrogation Of Collagen-Induced Arthritis By A Peptidyl Arginine Deiminase Inhibitor Is Associated With Modulation Of T Cell-Mediated Immune Responses, Joanna Kawalkowska, Anne-Marie Quirke, Fatemeh Ghari, Simon Davis, Venkataraman Subramanian, Paul R. Thompson, Richard O. Williams, Roman Fischer, Nicholas B. La Thangue, Patrick J. Venables May 2016

Abrogation Of Collagen-Induced Arthritis By A Peptidyl Arginine Deiminase Inhibitor Is Associated With Modulation Of T Cell-Mediated Immune Responses, Joanna Kawalkowska, Anne-Marie Quirke, Fatemeh Ghari, Simon Davis, Venkataraman Subramanian, Paul R. Thompson, Richard O. Williams, Roman Fischer, Nicholas B. La Thangue, Patrick J. Venables

Open Access Articles

Proteins containing citrulline, a post-translational modification of arginine, are generated by peptidyl arginine deiminases (PAD). Citrullinated proteins have pro-inflammatory effects in both innate and adaptive immune responses. Here, we examine the therapeutic effects in collagen-induced arthritis of the second generation PAD inhibitor, BB-Cl-amidine. Treatment after disease onset resulted in the reversal of clinical and histological changes of arthritis, associated with a marked reduction in citrullinated proteins in lymph nodes. There was little overall change in antibodies to collagen or antibodies to citrullinated peptides, but a shift from pro-inflammatory Th1 and Th17-type responses to pro-resolution Th2-type responses was demonstrated by serum ...


Theoretical And Experimental Analysis Of The Antioxidant And Anti-Amyloid Features Of Synthetic Resveratrol Mimics, William Horton, Anne Kokel, Fanni Török, Chris Tran, Marianna Török, Bela Török May 2016

Theoretical And Experimental Analysis Of The Antioxidant And Anti-Amyloid Features Of Synthetic Resveratrol Mimics, William Horton, Anne Kokel, Fanni Török, Chris Tran, Marianna Török, Bela Török

UMass Center for Clinical and Translational Science Research Retreat

Diaryl hydrazones, possessing similar structure to the popular red wine antioxidant resveratrol, have been previously identified as multitarget compounds interfering with several processes associated with the pathogenesis of Alzheimer’s disease (AD). These compounds exhibited particularly strong inhibition of the amyloid beta (A) peptide self-assembly, including blocking the formation of fibrils and oligomers, species that are widely accepted to be neurotoxic. The molecules were also powerful free radical scavengers and thus have a potential to defend against oxidative stress.

In order to learn more about the mode of action of the compounds, theoretical and experimental studies have been carried out ...


Crystal Protein Cry5b As A Novel And Powerful Anthelmintic, David Koch, Zeynep Mirza, Yan Hu, Thanh-Thanh Nguyen, Gary R. Ostroff, Raffi V. Aroian May 2016

Crystal Protein Cry5b As A Novel And Powerful Anthelmintic, David Koch, Zeynep Mirza, Yan Hu, Thanh-Thanh Nguyen, Gary R. Ostroff, Raffi V. Aroian

UMass Center for Clinical and Translational Science Research Retreat

Soil-transmitted helminths (STHs), most notably, hookworms, whipworms, and Ascaris, are nematodes that infect more than 1.5 billion of the poorest people and are amongst the leading causes of morbidity worldwide. Only two classes of de-worming drugs (anthelmintics) are available for treatment, and only one is commonly used in mass drug administrations. New anthelmintics are urgently needed to overcome emerging resistance and to produce higher cure rates. Crystal (Cry) proteins, in particular Cry5B, made by Bacillus thuringiensis (Bt) are promising new candidates. Cry5B has excellent anthelmintic properties against many free-living and parasitic nematodes, including in vivo efficacy against multiple STH ...


Structural Activity Relationship Study On Dual Plk1 /Brd4 Inhibitor, Bi- 2536, Hailemichael Yosief, Shuai Liu, Dennis L. Buckley, Justin M. Roberts, Alex M. Muthengi, Francesca M. Corsini, James E. Bradner, Wei Zhang May 2016

Structural Activity Relationship Study On Dual Plk1 /Brd4 Inhibitor, Bi- 2536, Hailemichael Yosief, Shuai Liu, Dennis L. Buckley, Justin M. Roberts, Alex M. Muthengi, Francesca M. Corsini, James E. Bradner, Wei Zhang

UMass Center for Clinical and Translational Science Research Retreat

Polo-like kinase 1 (PLK1) and BRD4 are two different therapeutic targets in cancer drug discovery. Recently it has been reported that PLK1 inhibitor, BI-2536, is also a potent inhibitor of BRD4. The simultaneous inhibition of PLK1 and BRD4 by a single drug molecule is interesting because this could lead to the development of effective therapeutic strategy for different types of disease conditions in which PLK1 and BRD4 are implicated. Structural activity relationship studies has been carried out on BI-2536 to generate analogs with enhanced dual inhibitory activity against BRD4 and PLK1 as well as to render the molecule selective to ...


Terpenes As ‘Resistance-Busting” Anthelmintic Drug, Zeynep Mirza, David Koch, Thanh-Thanh Nguyen, Yan Hu, Raffi V. Aroian, Gary R. Ostroff May 2016

Terpenes As ‘Resistance-Busting” Anthelmintic Drug, Zeynep Mirza, David Koch, Thanh-Thanh Nguyen, Yan Hu, Raffi V. Aroian, Gary R. Ostroff

UMass Center for Clinical and Translational Science Research Retreat

There is an urgent need for new therapies for parasitic helminthic diseases affecting 1.5-2 billion people worldwide due to the threat of wide-spread resistance development to existing treatments and due to problems of incomplete efficacies.

Terpenes are plant secondary metabolites and major essential oil constituents. Historically, the terpene thymol was successfully used to cure hookworm infections in the 1900’s. Although effective, large doses were needed and thymol treatment had significant side effects. Because free terpenes are absorbed in the stomach, less than 10% of oral terpenes entered the site where the parasites live. To overcome these problems we ...


Protein Arginine Methylation And Citrullination In Epigenetic Regulation, Jakob Fuhrmann, Paul R. Thompson Mar 2016

Protein Arginine Methylation And Citrullination In Epigenetic Regulation, Jakob Fuhrmann, Paul R. Thompson

Thompson Lab Publications

The post-translational modification of arginine residues represents a key mechanism for the epigenetic control of gene expression. Aberrant levels of histone arginine modifications have been linked to the development of several diseases including cancer. In recent years, great progress has been made in understanding the physiological role of individual arginine modifications and their effects on chromatin function. The present review aims to summarize the structural and functional aspects of histone arginine modifying enzymes and their impact on gene transcription. We will discuss the potential for targeting these proteins with small molecules in a variety of disease states.


Citrullination-Acetylation Interplay Guides E2f-1 Activity During The Inflammatory Response, Fatemeh Ghari, Anne-Marie Quirke, Shonagh Munro, Joanna Kawalkowska, Sarah Picaud, Joanna Mcgouran, Venkataraman Subramanian, Aaron Muth, Richard Williams, Benedikt Kessler, Paul R. Thompson, Panagis Fillipakopoulos, Stefan Knapp, Patrick J. Venables, Nicholas B. La Thangue Feb 2016

Citrullination-Acetylation Interplay Guides E2f-1 Activity During The Inflammatory Response, Fatemeh Ghari, Anne-Marie Quirke, Shonagh Munro, Joanna Kawalkowska, Sarah Picaud, Joanna Mcgouran, Venkataraman Subramanian, Aaron Muth, Richard Williams, Benedikt Kessler, Paul R. Thompson, Panagis Fillipakopoulos, Stefan Knapp, Patrick J. Venables, Nicholas B. La Thangue

Thompson Lab Publications

Peptidyl arginine deiminase 4 (PAD4) is a nuclear enzyme that converts arginine residues to citrulline. Although increasingly implicated in inflammatory disease and cancer, the mechanism of action of PAD4 and its functionally relevant pathways remains unclear. E2F transcription factors are a family of master regulators that coordinate gene expression during cellular proliferation and diverse cell fates. We show that E2F-1 is citrullinated by PAD4 in inflammatory cells. Citrullination of E2F-1 assists its chromatin association, specifically to cytokine genes in granulocyte cells. Mechanistically, citrullination augments binding of the BET (bromodomain and extra-terminal domain) family bromodomain reader BRD4 (bromodomain-containing protein 4) to ...