1
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Ito Y, Lu H, Kitajima M, Ishikawa H, Nakata Y, Iwatani Y, Hoshino T. Sticklac-Derived Natural Compounds Inhibiting RNase H Activity of HIV-1 Reverse Transcriptase. JOURNAL OF NATURAL PRODUCTS 2023; 86:2487-2495. [PMID: 37874155 DOI: 10.1021/acs.jnatprod.3c00662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The emergence of drug-resistant viruses is a serious concern in current chemotherapy for human immunodeficiency virus type-1 (HIV-1) infectious diseases. Hence, antiviral drugs aiming at targets that are different from those of approved drugs are still required, and the RNase H activity of HIV-1 reverse transcriptase is a suitable target. In this study, a search of a series of natural compounds was performed to identify the RNase H inhibitors. Three compounds were found to block the RNase H enzymatic activity. A laccaic acid skeleton was observed in all three natural compounds. A hydroxy phenyl group is connected to an anthraquinone backbone in the skeleton. An acetamido-ethyl, amino-carboxy-ethyl, and amino-ethyl are bound to the phenyl in laccaic acids A, C, and E, respectively. Laccaic acid C showed a 50% inhibitory concentration at 8.1 μM. Laccaic acid C also showed inhibitory activity in a cell-based viral proliferation assay. Binding structures of these three laccaic acids were determined by X-ray crystallographic analysis using a recombinant protein composed of the HIV-1 RNase H domain. Two divalent metal ions were located at the catalytic center in which one carbonyl and two hydroxy groups on the anthraquinone backbone chelated two metal ions. Molecular dynamics simulations were performed to examine the stabilities of the binding structures. Laccaic acid C showed the strongest binding to the catalytic site. These findings will be helpful for the design of potent inhibitors with modification of laccaic acids to enhance the binding affinity.
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Affiliation(s)
- Yuma Ito
- Laboratory of Molecular Design, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Huiyan Lu
- Laboratory of Molecular Design, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Mariko Kitajima
- Laboratory of Middle Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Hayato Ishikawa
- Laboratory of Middle Molecular Chemistry, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Yoshihiro Nakata
- Department of Infectious Diseases and Immunology, Clinical Research Center, National Hospital Organization Nagoya Medical Center, 4-1-1 Sannomaru, Naka-ku, Nagoya, Aichi 460-0001, Japan
| | - Yasumasa Iwatani
- Department of Infectious Diseases and Immunology, Clinical Research Center, National Hospital Organization Nagoya Medical Center, 4-1-1 Sannomaru, Naka-ku, Nagoya, Aichi 460-0001, Japan
- Department of AIDS Research, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Aichi 466-8550, Japan
| | - Tyuji Hoshino
- Laboratory of Molecular Design, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
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2
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Innocenti M. Investigating Mammalian Formins with SMIFH2 Fifteen Years in: Novel Targets and Unexpected Biology. Int J Mol Sci 2023; 24:ijms24109058. [PMID: 37240404 DOI: 10.3390/ijms24109058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/16/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023] Open
Abstract
The mammalian formin family comprises fifteen multi-domain proteins that regulate actin dynamics and microtubules in vitro and in cells. Evolutionarily conserved formin homology (FH) 1 and 2 domains allow formins to locally modulate the cell cytoskeleton. Formins are involved in several developmental and homeostatic processes, as well as human diseases. However, functional redundancy has long hampered studies of individual formins with genetic loss-of-function approaches and prevents the rapid inhibition of formin activities in cells. The discovery of small molecule inhibitor of formin homology 2 domains (SMIFH2) in 2009 was a disruptive change that provided a powerful chemical tool to explore formins' functions across biological scales. Here, I critically discuss the characterization of SMIFH2 as a pan-formin inhibitor, as well as growing evidence of unexpected off-target effects. By collating the literature and information hidden in public repositories, outstanding controversies and fundamental open questions about the substrates and mechanism of action of SMIFH2 emerge. Whenever possible, I propose explanations for these discrepancies and roadmaps to address the paramount open questions. Furthermore, I suggest that SMIFH2 be reclassified as a multi-target inhibitor for its appealing activities on proteins involved in pathological formin-dependent processes. Notwithstanding all drawbacks and limitations, SMIFH2 will continue to prove useful in studying formins in health and disease in the years to come.
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Affiliation(s)
- Metello Innocenti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
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3
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Lu H, Komukai Y, Usami K, Guo Y, Qiao X, Nukaga M, Hoshino T. Computational and Crystallographic Analysis of Binding Structures of Inhibitory Compounds for HIV-1 RNase H Activity. J Chem Inf Model 2022; 62:6762-6774. [PMID: 36184946 DOI: 10.1021/acs.jcim.2c00537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Chemotherapy of human immunodeficiency virus type-1 (HIV-1) has significantly developed over the last three decades. The emergence of drug-resistant variants is, however, still a severe problem. The RNase H activity of HIV-1 reverse transcriptase is an attractive target for a new class of antiviral drugs because there is no approved inhibitor. The nitro-furan-carbonyl and nitro-thiophene-carbonyl groups are potent scaffolds for the HIV-1 RNase H inhibitor. In this work, the binding structures of six inhibitory compounds were obtained by X-ray crystal analysis in a complex with a recombinant protein of HIV-1 RNase H domain. Every inhibitory compound was found to be bound to the catalytic site with the furan- or thiophene-ring coordinated to two divalent metal ions at the binding pocket. All the atoms in nitro, furan, carbonyl, and two metals were aligned in the nitro-furan derivatives. The straight line connecting nitro and carboxyl groups was parallel to the plane made by two metal ions and a furan O atom. The binding modes of the nitro-thiophene derivatives were slightly different from those of the nitro-furan ones. The nitro and carbonyl groups deviated from the plane made by two metals and a thiophene S atom. Molecular dynamics simulations suggested that the furan O or thiophene S atom and carbonyl O atom were firmly coordinated to the metal ions. The simulations made the planar nitro-furan moiety well aligned to the line connecting the two metal ions. In contrast, the nitro-thiophene derivatives were displaced from the initial positions after the simulations. The computational findings will be a sound basis for developing potent inhibitors for HIV-1 RNase H activity.
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Affiliation(s)
- Huiyan Lu
- Graduate School of Pharmaceutical Sciences, Chiba University Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
| | - Yuji Komukai
- Graduate School of Pharmaceutical Sciences, Chiba University Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
| | - Koto Usami
- Graduate School of Pharmaceutical Sciences, Chiba University Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
| | - Yan Guo
- Graduate School of Pharmaceutical Sciences, Chiba University Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
| | - Xinyue Qiao
- Graduate School of Pharmaceutical Sciences, Chiba University Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
| | - Michiyoshi Nukaga
- Faculty of Pharmaceutical Sciences, Josai International University Gumyo 1, Togane-shi Chiba 283-8555, Japan
| | - Tyuji Hoshino
- Graduate School of Pharmaceutical Sciences, Chiba University Inohana 1-8-1, Chuo-ku, Chiba 260-8675, Japan
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4
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RNase HI Depletion Strongly Potentiates Cell Killing by Rifampicin in Mycobacteria. Antimicrob Agents Chemother 2022; 66:e0209121. [PMID: 36154174 DOI: 10.1128/aac.02091-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Multidrug-resistant (MDR) tuberculosis (TB) is defined by the resistance of Mycobacterium tuberculosis, the causative organism, to the first-line antibiotics rifampicin and isoniazid. Mitigating or reversing resistance to these drugs offers a means of preserving and extending their use in TB treatment. R-loops are RNA/DNA hybrids that are formed in the genome during transcription, and they can be lethal to the cell if not resolved. RNase HI is an enzyme that removes R-loops, and this activity is essential in M. tuberculosis: knockouts of rnhC, the gene encoding RNase HI, are nonviable. This essentiality makes it a candidate target for the development of new antibiotics. In the model organism Mycolicibacterium smegmatis, RNase HI activity is provided by two enzymes, RnhA and RnhC. We show that the partial depletion of RNase HI activity in M. smegmatis, by knocking out either of the genes encoding RnhA or RnhC, led to the accumulation of R-loops. The sensitivity of the knockout strains to the antibiotics moxifloxacin, streptomycin, and rifampicin was increased, the latter by a striking near 100-fold. We also show that R-loop accumulation accompanies partial transcriptional inhibition, suggesting a mechanistic basis for the synergy between RNase HI depletion and rifampicin. A model of how transcriptional inhibition can potentiate R-loop accumulation is presented. Finally, we identified four small molecules that inhibit recombinant RnhC activity and that also potentiated rifampicin activity in whole-cell assays against M. tuberculosis, supporting an on-target mode of action and providing the first step in developing a new class of antimycobacterial drug.
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5
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Xie Z, Chen S, Zhang W, Zhao S, Zhao Z, Wang X, Huang Y, Yi G. A novel fluorescence amplification strategy combining cascade primer exchange reaction with CRISPR/Cas12a system for ultrasensitive detection of RNase H activity. Biosens Bioelectron 2022; 206:114135. [DOI: 10.1016/j.bios.2022.114135] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/17/2022] [Accepted: 02/24/2022] [Indexed: 12/16/2022]
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6
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Ilina TV, Brosenitsch T, Sluis-Cremer N, Ishima R. Retroviral RNase H: Structure, mechanism, and inhibition. Enzymes 2021; 50:227-247. [PMID: 34861939 DOI: 10.1016/bs.enz.2021.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
All retroviruses encode the enzyme, reverse transcriptase (RT), which is involved in the conversion of the single-stranded viral RNA genome into double-stranded DNA. RT is a multifunctional enzyme and exhibits DNA polymerase and ribonuclease H (RNH) activities, both of which are essential to the reverse-transcription process. Despite the successful development of polymerase-targeting antiviral drugs over the last three decades, no bona fide inhibitor against the RNH activity of HIV-1 RT has progressed to clinical evaluation. In this review article, we describe the retroviral RNH function and inhibition, with primary consideration of the structural aspects of inhibition.
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Affiliation(s)
- Tatiana V Ilina
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Teresa Brosenitsch
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Nicolas Sluis-Cremer
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Rieko Ishima
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
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7
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Hu Y, Xie Q, Chang L, Tao X, Tong C, Liu B, Wang W. A radar-like DNA monitor for RNase H-targeted natural compounds screening and RNase H activity in situ detection. Analyst 2021; 146:5980-5987. [PMID: 34499070 DOI: 10.1039/d1an01046h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ribonuclease H is essential for the research and development of complex pathema. The high rigidity and versatility of DNA tetrahedrons means they are often used in biosensing systems. Inspired by "radar" technology, we proposed a radar-like monitor to detect RNase H activity in vitro and in situ by integrating DNA tetrahedral elements. The structure of a radar-like monitor was self-assembled from five customized single nucleic acid strands. Four DNA strands were assembled as DNA tetrahedrons with a long strand labeled by Dabcyl (quencher) at one of the apexes, while the fifth strand (DNA-RNA heterozygous strand) was labeled with a FAM (Fluorophore) hybrid with a long strand. The fluorescence was quenched because the fluorophore and the quencher were very close. In the presence of RNase H, the RNA chain was hydrolyzed and the fluorophore released, resulting in fluorescence recovery. The radar-like monitor was used to detect the RNase H activity in vitro with a detection limit of 0.01 U mL-1. Based on the RNase H activity detection and the inhibitory effect of natural-compounds-targeting RNase H, three inhibitors were obtained among 35 compounds extracted from Panax japonicus. Therefore, the radar-like monitor was successfully used to detect RNase H activity in situ due to the long-term anti-DNase I effect of the RNA/DNA hybrid structure and DNA tetrahedrons structure. Overall, this radar-like monitor can effectively avoid false-positive signals and significantly improve the accuracy, precision, and reliability of detection. It is expected that the development of such an intelligent nano-platform will open the door to cancer diagnosis and treatment in clinical systems.
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Affiliation(s)
- Yalei Hu
- College of Biology, Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha, 410082, China.
| | - Qian Xie
- TCM and Ethnomedicine Innovation & Development International Laboratory, Innovative Material Medical Research Institute, School of Pharmacy, Hunan University of Chinese Medicine, Changsha, 410208, China.
| | - Li Chang
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410008, PR China
| | - Xueqing Tao
- College of Biology, Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha, 410082, China.
| | - Chunyi Tong
- College of Biology, Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha, 410082, China.
| | - Bin Liu
- College of Biology, Hunan Province Key Laboratory of Plant Functional Genomics and Developmental Regulation, Hunan University, Changsha, 410082, China.
| | - Wei Wang
- TCM and Ethnomedicine Innovation & Development International Laboratory, Innovative Material Medical Research Institute, School of Pharmacy, Hunan University of Chinese Medicine, Changsha, 410208, China.
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8
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Messore A, Corona A, Madia VN, Saccoliti F, Tudino V, De Leo A, Ialongo D, Scipione L, De Vita D, Amendola G, Novellino E, Cosconati S, Métifiot M, Andreola ML, Esposito F, Grandi N, Tramontano E, Costi R, Di Santo R. Quinolinonyl Non-Diketo Acid Derivatives as Inhibitors of HIV-1 Ribonuclease H and Polymerase Functions of Reverse Transcriptase. J Med Chem 2021; 64:8579-8598. [PMID: 34106711 PMCID: PMC8279492 DOI: 10.1021/acs.jmedchem.1c00535] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
![]()
Novel anti-HIV agents
are still needed to overcome resistance issues,
in particular inhibitors acting against novel viral targets. The ribonuclease
H (RNase H) function of the reverse transcriptase (RT) represents
a validated and promising target, and no inhibitor has reached the
clinical pipeline yet. Here, we present rationally designed non-diketo
acid selective RNase H inhibitors (RHIs) based on the quinolinone
scaffold starting from former dual integrase (IN)/RNase H quinolinonyl
diketo acids. Several derivatives were synthesized and tested against
RNase H and viral replication and found active at micromolar concentrations.
Docking studies within the RNase H catalytic site, coupled with site-directed
mutagenesis, and Mg2+ titration experiments demonstrated
that our compounds coordinate the Mg2+ cofactor and interact
with amino acids of the RNase H domain that are highly conserved among
naïve and treatment-experienced patients. In general, the new
inhibitors influenced also the polymerase activity of RT but were
selective against RNase H vs the IN enzyme.
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Affiliation(s)
- Antonella Messore
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, "Sapienza" Università di Roma, p.le Aldo Moro 5, I-00185 Rome, Italy
| | - Angela Corona
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS554-09042 Monserrato (CA), Italy
| | - Valentina Noemi Madia
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, "Sapienza" Università di Roma, p.le Aldo Moro 5, I-00185 Rome, Italy
| | - Francesco Saccoliti
- D3 PharmaChemistry, Italian Institute of Technology, Via Morego 30, I-16163 Genova, Italy
| | - Valeria Tudino
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, "Sapienza" Università di Roma, p.le Aldo Moro 5, I-00185 Rome, Italy
| | - Alessandro De Leo
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, "Sapienza" Università di Roma, p.le Aldo Moro 5, I-00185 Rome, Italy
| | - Davide Ialongo
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, "Sapienza" Università di Roma, p.le Aldo Moro 5, I-00185 Rome, Italy
| | - Luigi Scipione
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, "Sapienza" Università di Roma, p.le Aldo Moro 5, I-00185 Rome, Italy
| | - Daniela De Vita
- Department of Environmental Biology, "Sapienza" University of Rome, p.le Aldo Moro 5, I-00185 Rome, Italy
| | - Giorgio Amendola
- DiSTABiF, University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100 Caserta, Italy
| | - Ettore Novellino
- Department of Pharmacy, University Federico II of Naples, Via D. Montesano 49, 80131 Naples, Italy
| | - Sandro Cosconati
- DiSTABiF, University of Campania "Luigi Vanvitelli", Via Vivaldi 43, 81100 Caserta, Italy
| | - Mathieu Métifiot
- Laboratoire MFP, UMR 5234, CNRS - Université de Bordeaux, 146 rue Léo Saignat, 33076 Bordeaux cedex, France
| | - Marie-Line Andreola
- Laboratoire MFP, UMR 5234, CNRS - Université de Bordeaux, 146 rue Léo Saignat, 33076 Bordeaux cedex, France
| | - Francesca Esposito
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS554-09042 Monserrato (CA), Italy
| | - Nicole Grandi
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS554-09042 Monserrato (CA), Italy
| | - Enzo Tramontano
- Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, SS554-09042 Monserrato (CA), Italy
| | - Roberta Costi
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, "Sapienza" Università di Roma, p.le Aldo Moro 5, I-00185 Rome, Italy
| | - Roberto Di Santo
- Dipartimento di Chimica e Tecnologie del Farmaco, Istituto Pasteur-Fondazione Cenci Bolognetti, "Sapienza" Università di Roma, p.le Aldo Moro 5, I-00185 Rome, Italy
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9
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Woo J, Kim JH, Kim S, Park KS. Promoter engineering improves transcription efficiency in biomolecular assays. Chem Commun (Camb) 2021; 57:1619-1622. [PMID: 33458724 DOI: 10.1039/d0cc07797f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We identified a novel 12 bp promoter that significantly increased transcription efficiency. Unlike the standard 20 bp promoter, which contains both recognition and initiation regions, the new promoter contains only a recognition region and is more suitable for diagnostic applications due to its smaller size. This promoter effectively produced different light-up RNA aptamers via transcription. Moreover, we used the promoter to analyze RNase H activity and achieved a detection limit of 0.009 U mL-1, which was significantly better than that achieved via previous methods. We propose that the new promoter may serve as a key component in various diagnostic applications.
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Affiliation(s)
- Jisu Woo
- Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Republic of Korea.
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10
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Duggal Y, Fontaine BM, Dailey DM, Ning G, Weinert EE. RNase I Modulates Escherichia coli Motility, Metabolism, and Resistance. ACS Chem Biol 2020; 15:1996-2004. [PMID: 32551492 DOI: 10.1021/acschembio.0c00390] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Bacteria are constantly adapting to their environment by sensing extracellular factors that trigger production of intracellular signaling molecules, known as second messengers. Recently, 2',3'-cyclic nucleotide monophosphates (2',3'-cNMPs) were identified in Escherichia coli and have emerged as possible novel signaling molecules. 2',3'-cNMPs are produced through endonucleolytic cleavage of short RNAs by the T2 endoribonuclease, RNase I; however, the physiological roles of RNase I remain unclear. Our transcriptomic analysis suggests that RNase I is involved in modulating numerous cellular processes, including nucleotide metabolism, motility, acid sensitivity, metal homeostasis, and outer membrane morphology. Through a combination of deletion strain and inhibitor studies, we demonstrate that RNase I plays a previously unknown role in E. coli stress resistance by affecting pathways that are part of the defense mechanisms employed by bacteria when introduced to external threats, including antibiotics. Thus, this work provides insight into the emerging roles of RNase I in bacterial signaling and physiology and highlights the potential of RNase I as a target for antibacterial adjuvants.
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Affiliation(s)
- Yashasvika Duggal
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Benjamin M. Fontaine
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Deanna M. Dailey
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Gang Ning
- Microscopy Facility, Huck Institute of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Emily E. Weinert
- Department of Chemistry, Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, United States
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11
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Affiliation(s)
- Matthew D. Lloyd
- Drug & Target Development, Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, U.K
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12
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Baba M, Kojima K, Nishimura T, Sugiura T, Takita T, Uehara R, Crouch RJ, Yasukawa K. Val143 of human ribonuclease H2 is not critical for, but plays a role in determining catalytic activity and substrate specificity. PLoS One 2020; 15:e0228774. [PMID: 32069311 PMCID: PMC7028304 DOI: 10.1371/journal.pone.0228774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/22/2020] [Indexed: 11/18/2022] Open
Abstract
Ribonuclease H2 (RNase H2) exhibits both single ribonucleotide excision activity (activity A) and RNA strand degrading activity (activity B). Val143 of human RNase H2 is located at the active site and is conserved in eukaryotic RNase H2. In this study, we explored the role of Val143 in catalytic activity and substrate specificity. Nineteen single variants at amino acid position 143 were expressed in E. coli, and all variants except for V143C and V143M were purified from the cells. When the activity of the wild-type human RNase H2 (WT) was set as 100%, the relative activities A and B of the 17 variants were in the range of 0.05–130 and 0.02–42%, respectively. When the ratio of the relative activity A to the relative activity B of WT was set as 1, the ratios of the 17 variants were in the range of 0.2–5.7. This indicates that valine is optimal for balancing the two activities. The ratios for V143Y and V143W were relatively high (5.6 and 5.5, respectively), suggesting that the bulky residues like tyrosine and tryptophan at position 143 caused steric hindrance with the 2’-OH of the sugar moiety of the ribonucleotide at the 5’ side of the scissile phosphodiester bond. The ratio for V143Q was relatively low (0.2). These results suggested that Val143 is not critical for, but plays a role in determining catalytic activity and substrate specificity.
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Affiliation(s)
- Misato Baba
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kenji Kojima
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Takuto Nishimura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Takuya Sugiura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Teisuke Takita
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Ryo Uehara
- Section on Formation of RNA, Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
- Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Noji-higashi, Shiga, Japan
| | - Robert J. Crouch
- Section on Formation of RNA, Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Kiyoshi Yasukawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
- * E-mail:
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13
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Wang Y, Hu N, Liu C, Nie C, He M, Zhang J, Yu Q, Zhao C, Chen T, Chu X. An RNase H-powered DNA walking machine for sensitive detection of RNase H and the screening of related inhibitors. NANOSCALE 2020; 12:1673-1679. [PMID: 31894217 DOI: 10.1039/c9nr07550j] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Ribonuclease H (RNase H), an intracellular ribonuclease, plays a crucial role in cellular processes and especially relates to many disease processes. Here, we report a novel signal amplification strategy based on an RNase H-powered DNA walking machine for specific and sensitive RNase H activity detection. The DNA walking machine is composed of a small quantity of DNA walker strands and abundant FAM-labeled DNA-RNA chimeric strands on a single gold nanoparticle (AuNP). RNase H can specifically degrade the RNA fragment in a DNA-RNA hybrid duplex and trigger the autonomous movement of a DNA walker strand on the AuNP surface. During this process, each step of the walking can release the FAM-labeled RNA from the surface of the AuNP, realizing the signal amplification for RNase H sensing. This method has been successfully utilized for RNase H activity detection in a complex system and applied for screening of related inhibitors. Therefore, our RNase H-powered DNA walking machine gives a novel platform for RNase H activity detection and RNase H-associated drug discovery.
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Affiliation(s)
- Yafang Wang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, P. R. China.
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14
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Nishimura T, Baba M, Ogawa S, Kojima K, Takita T, Crouch RJ, Yasukawa K. Characterization of six recombinant human RNase H2 bearing Aicardi-Goutiéres syndrome causing mutations. J Biochem 2019; 166:537-545. [PMID: 31529068 DOI: 10.1093/jb/mvz073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 09/02/2019] [Indexed: 01/18/2023] Open
Abstract
Mammalian RNase H2 is a heterotrimeric enzyme consisting of one catalytic subunit (A) and two accessory subunits (B and C). RNase H2 is involved in the removal of a single ribonucleotide embedded in genomic DNA and removal of RNA of RNA/DNA hybrids. In humans, mutation of the RNase H2 gene causes a severe neuroinflammatory disorder Aicardi-Goutières syndrome (AGS). Here, we examined the activity and stability of six recombinant human RNase H2 variants bearing one AGS-causing mutation, A-G37S (Gly37 in the A subunit is replaced with Ser), A-N212I, A-R291H, B-A177T, B-V185G, or C-R69W. The activity of A-G37S was 0.3-1% of that of the wild-type RNase H2 (WT), while those of other five variants were 51-120%. In circular dichroism measurement, the melting temperatures of variants were 50-53°C, lower than that of WT (56°C). These results suggested that A-G37S had decreased activity and stability than WT, while other five variants had decreased stability but retained activity. In gel filtration chromatography of the purified enzyme preparation, WT migrated as a heterotrimer, while A-R291H eluted in two separate peaks containing either the heterotrimer or only the A subunit, suggesting that some AGS-causing mutations affect the heterotrimer-forming stability of RNase H2.
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Affiliation(s)
- Takuto Nishimura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyoku, Kyoto 606-8502, Japan
| | - Misato Baba
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyoku, Kyoto 606-8502, Japan
| | - Saori Ogawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyoku, Kyoto 606-8502, Japan
| | - Kenji Kojima
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyoku, Kyoto 606-8502, Japan
| | - Teisuke Takita
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyoku, Kyoto 606-8502, Japan
| | - Robert J Crouch
- Section on Formation of RNA, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kiyoshi Yasukawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyoku, Kyoto 606-8502, Japan
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15
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Tramontano E, Corona A, Menéndez-Arias L. Ribonuclease H, an unexploited target for antiviral intervention against HIV and hepatitis B virus. Antiviral Res 2019; 171:104613. [PMID: 31550450 DOI: 10.1016/j.antiviral.2019.104613] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 12/18/2022]
Abstract
Ribonucleases H (RNases H) are endonucleolytic enzymes, evolutionarily related to retroviral integrases, DNA transposases, resolvases and numerous nucleases. RNases H cleave RNA in RNA/DNA hybrids and their activity plays an important role in the replication of prokaryotic and eukaryotic genomes, as well as in the replication of reverse-transcribing viruses. During reverse transcription, the RNase H activity of human immunodeficiency virus (HIV) and hepatitis B virus (HBV) degrades the viral genomic RNA to facilitate the synthesis of viral double-stranded DNA. HIV and HBV reverse transcriptases contain DNA polymerase and RNase H domains that act in a coordinated manner to produce double-stranded viral DNA. Although RNase H inhibitors have not been developed into licensed drugs, recent progress has led to the identification of a number of small molecules with inhibitory activity at low micromolar or even nanomolar concentrations. These compounds can be classified into metal-chelating active site inhibitors and allosteric inhibitors. Among them, α-hydroxytropolones, N-hydroxyisoquinolinediones and N-hydroxypyridinediones represent chemotypes active against both HIV and HBV RNases H. In this review we summarize recent developments in the field including the identification of novel RNase H inhibitors, compounds with dual inhibitory activity, broad specificity and efforts to decrease their toxicity.
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Affiliation(s)
- Enzo Tramontano
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy.
| | - Angela Corona
- Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Luis Menéndez-Arias
- Centro de Biología Molecular "Severo Ochoa" (Consejo Superior de Investigaciones Científicas & Universidad Autónoma de Madrid), Madrid, Spain.
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16
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Biological evaluation of molecules of the azaBINOL class as antiviral agents: Inhibition of HIV-1 RNase H activity by 7-isopropoxy-8-(naphth-1-yl)quinoline. Bioorg Med Chem 2019; 27:3595-3604. [DOI: 10.1016/j.bmc.2019.06.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/22/2019] [Accepted: 06/27/2019] [Indexed: 12/13/2022]
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17
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Tang J, Do HT, Huber AD, Casey MC, Kirby KA, Wilson DJ, Kankanala J, Parniak MA, Sarafianos SG, Wang Z. Pharmacophore-based design of novel 3-hydroxypyrimidine-2,4-dione subtypes as inhibitors of HIV reverse transcriptase-associated RNase H: Tolerance of a nonflexible linker. Eur J Med Chem 2019; 166:390-399. [PMID: 30739822 PMCID: PMC6459026 DOI: 10.1016/j.ejmech.2019.01.081] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/17/2019] [Accepted: 01/30/2019] [Indexed: 11/29/2022]
Abstract
The pharmacophore of active site inhibitors of human immunodeficiency virus (HIV) reverse transcriptase (RT)-associated RNase H typically entails a flexible linker connecting the chelating core and the hydrophobic aromatics. We report herein that novel 3-hydroxypyrimidine-2,4-dione (HPD) subtypes with a nonflexible C-6 carbonyl linkage exhibited potent and selective biochemical inhibitory profiles with strong RNase H inhibition at low nM, weak to moderate integrase strand transfer (INST) inhibition at low μM, and no to marginal RT polymerase (pol) inhibition up to 10 μM. A few analogues also demonstrated significant antiviral activity without cytotoxicity. The overall inhibitory profile is comparable to or better than that of previous HPD subtypes with a flexible C-6 linker, suggesting that the nonflexible carbonyl linker can be tolerated in the design of novel HIV RNase H active site inhibitors.
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Affiliation(s)
- Jing Tang
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Ha T Do
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Andrew D Huber
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA
| | - Mary C Casey
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA
| | - Karen A Kirby
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Daniel J Wilson
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jayakanth Kankanala
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Michael A Parniak
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA; Department of Biochemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Zhengqiang Wang
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA.
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18
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Wang L, Tang J, Huber AD, Casey MC, Kirby KA, Wilson DJ, Kankanala J, Parniak MA, Sarafianos SG, Wang Z. 6-Biphenylmethyl-3-hydroxypyrimidine-2,4-diones potently and selectively inhibited HIV reverse transcriptase-associated RNase H. Eur J Med Chem 2018; 156:680-691. [PMID: 30031978 DOI: 10.1016/j.ejmech.2018.07.035] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/11/2018] [Accepted: 07/14/2018] [Indexed: 12/11/2022]
Abstract
Human immunodeficiency virus (HIV) reverse transcriptase (RT)-associated ribonuclease H (RNase H) remains an unvalidated drug target. Reported HIV RNase H inhibitors generally lack significant antiviral activity. We report herein the design, synthesis, biochemical and antiviral evaluations of a new 6-biphenylmethyl subtype of the 3-hydroxypyrimidine-2,4-dione (HPD) chemotype. In biochemical assays, analogues of this new subtype potently inhibited RT RNase H in low nanomolar range without inhibiting RT polymerase (pol) or integrase strand transfer (INST) at the highest concentrations tested. In cell-based assays, a few analogues inhibited HIV in low micromolar range without cytotoxicity at concentrations up to 100 μM.
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Affiliation(s)
- Lei Wang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jing Tang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Andrew D Huber
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
| | - Mary C Casey
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
| | - Karen A Kirby
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jayakanth Kankanala
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Michael A Parniak
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA.
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19
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Wang L, Tang J, Huber AD, Casey MC, Kirby KA, Wilson DJ, Kankanala J, Xie J, Parniak MA, Sarafianos SG, Wang Z. 6-Arylthio-3-hydroxypyrimidine-2,4-diones potently inhibited HIV reverse transcriptase-associated RNase H with antiviral activity. Eur J Med Chem 2018; 156:652-665. [PMID: 30031976 DOI: 10.1016/j.ejmech.2018.07.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 05/31/2018] [Accepted: 07/15/2018] [Indexed: 12/17/2022]
Abstract
Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) remains the only virally encoded enzymatic function not targeted by current drugs. Although a few chemotypes have been reported to inhibit HIV RNase H in biochemical assays, their general lack of significant antiviral activity in cell culture necessitates continued efforts in identifying highly potent RNase H inhibitors to confer antiviral activity. We report herein the design, synthesis, biochemical and antiviral evaluations of a new 6-arylthio subtype of the 3-hydroxypyrimidine-2,4-dione (HPD) chemotype. In biochemical assays these new analogues inhibited RT RNase H in single-digit nanomolar range without inhibiting RT polymerase (pol) at concentrations up to 10 μM, amounting to exceptional biochemical inhibitory selectivity. Many analogues also inhibited integrase strand transfer (INST) activity in low to sub micromolar range. More importantly, most analogues inhibited HIV in low micromolar range without cytotoxicity. In the end, compound 13j (RNase H IC50 = 0.005 μM; RT pol IC50 = 10 μM; INST IC50 = 4.0 μM; antiviral EC50 = 7.7 μM; CC50 > 100 μM) represents the best analogues within this series. These results characterize the new 6-arylthio-HPD subtype as a promising scaffold for HIV RNase H inhibitor discovery.
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Affiliation(s)
- Lei Wang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jing Tang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Andrew D Huber
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA
| | - Mary C Casey
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA
| | - Karen A Kirby
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jayakanth Kankanala
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Jiashu Xie
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Michael A Parniak
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA; Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, 30322, USA; Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO, 65211, USA
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, USA.
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20
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Abstract
Heteroduplex oligonucleotides (HDOs), composed of a DNA/LNA gapmer and its complementary RNA, are a novel, promising candidates for antisense drugs. We previously reported oligodiaminogalactoses (ODAGals), designed to bind to A-type nucleic acid duplexes such as DNA/RNA and RNA/RNA duplexes. In this paper, we report oligodiguanidinogalactoses (ODGGals) as novel A-type duplex binding molecules. We aimed to study in detail applicability of ODAGals and ODGGals for additives to HDOs as an antisense drug. The effect of ODAGal4 (ODAGal 4mer) and ODGGal3 (ODGGal 3mer) on an HDO were evaluated by UV melting analyses, RNA degradation study by ribonuclease A (RNase A), and ribonuclease H (RNase H). Cleavage of a 13mer HDO by RNase A, which is considered to be the main cause of RNA degradation in serum, was effectively inhibited by the addition of only one equivalent of ODAGal4 and ODGGal3. In contrast, RNase H activity, which involves the cleavage of target RNAs by an antisense mechanism, was only slightly affected by the presence of the cationic oligosaccharides. These results suggest that ODAGal4 and ODGGal3 are useful because they could both stabilize the HDO and maintain RNase H activity of the gapmer.
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21
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SJP-L-5 inhibits HIV-1 polypurine tract primed plus-strand DNA elongation, indicating viral DNA synthesis initiation at multiple sites under drug pressure. Sci Rep 2018; 8:2574. [PMID: 29416083 PMCID: PMC5803243 DOI: 10.1038/s41598-018-20954-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/24/2018] [Indexed: 01/08/2023] Open
Abstract
In a previous study the small molecule SJP-L-5 that inhibits HIV replication, has been shown to block uncoating of the viral capsid. Continued study showed that SJP-L-5 might hinder HIV capsid uncoating by blocking the completion of reverse transcription. However, to date, the mechanism has not been fully elucidated. Here, the effects of SJP-L-5 for reverse transcription were explored via quantitative PCR, DIG-labelled ELISA, fluorescent resonance energy transfer, and Southern blot assays. We also analyzed the resistance profile of this compound against reverse transcriptase. Our results show that SJP-L-5 preferentially inhibits PPT primed plus-strand DNA synthesis (EC50 = 13.4 ± 3.0 μM) over RNA primed minus-strand DNA synthesis (EC50 > 3,646 μM), resulting in formation of five segmented plus-strand DNA and loss of HIV DNA flap, suggesting failure of both nuclear import and integration. Moreover, resistance study evidenced that SJP-L-5 requires the amino acid residues Val108 and Tyr181 to exert an inhibitory effect. These results indicate SJP-L-5 as a new non-nucleoside reverse transcriptase inhibitor that inhibits HIV-1 polypurine tract primed plus-strand DNA synthesis, initiating HIV-1 down-stream plus-strand DNA synthesis at multiple sites under drug pressure.
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22
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Hara RI, Maeda Y, Fujimaki H, Wada T. Enhancement in RNase H activity of a DNA/RNA hybrid duplex using artificial cationic oligopeptides. Chem Commun (Camb) 2018; 54:8526-8529. [DOI: 10.1039/c8cc04082f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
This study assessed the effects of artificial cationic oligopeptides on a DNA/RNA hybrid duplex.
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Affiliation(s)
- Rintaro Iwata Hara
- Faculty of Pharmaceutical Sciences
- Tokyo University of Science
- Noda
- Japan
- Department of Neurology and Neurological Science
| | - Yusuke Maeda
- Faculty of Pharmaceutical Sciences
- Tokyo University of Science
- Noda
- Japan
| | - Haruna Fujimaki
- Graduate School of Frontier Sciences
- The University of Tokyo
- Kashiwa
- Japan
| | - Takeshi Wada
- Faculty of Pharmaceutical Sciences
- Tokyo University of Science
- Noda
- Japan
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23
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Lee CY, Jang H, Park KS, Park HG. A label-free and enzyme-free signal amplification strategy for a sensitive RNase H activity assay. NANOSCALE 2017; 9:16149-16153. [PMID: 28980684 DOI: 10.1039/c7nr04060a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We herein describe a label-free and enzyme-free signal amplification strategy for the sensitive determination of ribonuclease H (RNase H) activity, which relies on the target-triggered catalytic hairpin assembly (CHA) in conjunction with a G-quadruplex specific fluorescent binder, N-methyl mesoporphyrin IX (NMM). In the absence of RNase H, the RNA/DNA duplex serving as a substrate for RNase H cannot initiate the execution of CHA that produces G-quadruplexes; so NMM shows a low fluorescence signal. In contrast, the presence of RNase H that degrades RNA in the RNA/DNA duplex releases DNA designed to function as the catalyst for CHA. This consequently promotes the efficient CHA and generates a large number of G-quadruplexes with a significantly enhanced fluorescence signal from NMM. Based on this label-free and enzyme-free signal amplification strategy, we successfully determined the RNase H activity with a detection limit of 0.037 U mL-1 and screened potential RNase H inhibitors. Our results suggest that the developed system is a promising platform for a cost-effective, sensitive enzyme activity assay and inhibitor screening.
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Affiliation(s)
- Chang Yeol Lee
- Department of Chemical and Biomolecular Engineering (BK 21+ program), KAIST, Daehak-ro 291, Yuseong-gu, Daejeon 305-338, Republic of Korea.
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24
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Baba M, Kojima K, Nakase R, Imai S, Yamasaki T, Takita T, Crouch RJ, Yasukawa K. Effects of neutral salts and pH on the activity and stability of human RNase H2. J Biochem 2017; 162:211-219. [PMID: 28402412 DOI: 10.1093/jb/mvx021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 02/13/2017] [Indexed: 11/14/2022] Open
Abstract
Ribonuclease H (RNase H) specifically degrades the RNA of RNA/DNA hybrid. Recent study has shown that a single ribonucleotide is embedded in DNA double strand at every few thousand base pairs in human genome, and human RNase H2 is involved in its removal. Here, we examined the effects of neutral salts and pH on the activity and stability of human RNase H2. NaCl, KCl, RbCl and NaBr increased the activity to 170-390% at 10-60 mM, while LiCl, LiBr and CsCl inhibited it, suggesting that species of cation, but not anion, is responsible for the effect on activity. NaCl and KCl increased the stability by decreasing the first-order rate constant of the inactivation to 50-60% at 60-80 mM. The activity at 25-35 °C exhibited a narrow bell-shaped pH-dependence with the acidic and alkaline pKe (pKe1 and pKe2) values of 7.3 - 7.6 and 8.1 - 8.8, respectively. Enthalpy changes (ΔH°) of deprotonation were 5 ± 21 kJ mol-1 for pKe1 and 68 ± 25 kJ mol-1 for pKe2. These results suggest that the ionizable groups responsible for pKe1 may be two out of Asp34, Glu35 and Asp141 of DEDD motif, and that for pKe2 may be Lys69 of DSK motif.
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Affiliation(s)
- Misato Baba
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kenji Kojima
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Rihoko Nakase
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Shota Imai
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Tomomi Yamasaki
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Teisuke Takita
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
| | - Robert J Crouch
- Section on Formation of RNA, Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kiyoshi Yasukawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan
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25
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Kankanala J, Kirby KA, Huber AD, Casey MC, Wilson DJ, Sarafianos SG, Wang Z. Design, synthesis and biological evaluations of N-Hydroxy thienopyrimidine-2,4-diones as inhibitors of HIV reverse transcriptase-associated RNase H. Eur J Med Chem 2017; 141:149-161. [PMID: 29031062 DOI: 10.1016/j.ejmech.2017.09.054] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 09/13/2017] [Accepted: 09/25/2017] [Indexed: 11/29/2022]
Abstract
Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) is the only HIV enzymatic function not targeted by current antiviral drugs. Although various chemotypes have been reported to inhibit HIV RNase H, few have shown significant antiviral activities. We report herein the design, synthesis and biological evaluation of a novel N-hydroxy thienopyrimidine-2,3-dione chemotype (11) which potently and selectively inhibited RNase H with considerable potency against HIV-1 in cell culture. Current structure-activity-relationship (SAR) identified analogue 11d as a nanomolar inhibitor of RNase H (IC50 = 0.04 μM) with decent antiviral potency (EC50 = 7.4 μM) and no cytotoxicity (CC50 > 100 μM). In extended biochemical assays compound 11d did not inhibit RT polymerase (pol) while inhibiting integrase strand transfer (INST) with 53 fold lower potency (IC50 = 2.1 μM) than RNase H inhibition. Crystallographic and molecular modeling studies confirmed the RNase H active site binding mode.
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Affiliation(s)
- Jayakanth Kankanala
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Karen A Kirby
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Department of Molecular Microbiology & Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Andrew D Huber
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Mary C Casey
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Department of Molecular Microbiology & Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Stefan G Sarafianos
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Department of Molecular Microbiology & Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, USA; Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA.
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26
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Lim SB, Cha SH, Jegal S, Jun H, Park SH, Jeon BY, Pak JH, Bakh YY, Kim TS, Lee HW. Characterization of Echinostoma cinetorchis endoribonuclease, RNase H. THE KOREAN JOURNAL OF PARASITOLOGY 2017; 55:451-455. [PMID: 28877580 PMCID: PMC5594731 DOI: 10.3347/kjp.2017.55.4.451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 07/27/2017] [Accepted: 08/02/2017] [Indexed: 11/23/2022]
Abstract
Echinostoma cinetorchis is an oriental intestinal fluke causing significant pathological damage to the small intestine. The aim of this study was to determine a full-length cDNA sequence of E. cinetorchis endoribonuclease (RNase H; EcRNH) and to elucidate its molecular biological characters. EcRNH consisted of 308 amino acids and showed low similarity to endoribonucleases of other parasites (<40%). EcRNH had an active site centered on a putative DDEED motif instead of DEDD conserved in other species. A recombinant EcRNH produced as a soluble form in Escherichia coli showed enzymatic activity to cleave the 3'-O-P bond of RNA in a DNA-RNA duplex, producing 3'-hydroxyl and 5'-phosphate. These findings may contribute to develop antisense oligonucleotides which could damage echinostomes and other flukes.
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Affiliation(s)
- Sung-Bin Lim
- Department of Tropical Medicine and Parasitology, Inha University School of Medicine, Incheon 22212, Korea.,Department of Bioscience, Dongkuk University, Seoul 04620, Korea
| | - Seok Ho Cha
- Department of Tropical Medicine and Parasitology, Inha University School of Medicine, Incheon 22212, Korea
| | - Seung Jegal
- Department of Tropical Medicine and Parasitology, Inha University School of Medicine, Incheon 22212, Korea.,Department of Infectious Diseases Diagnosis, Incheon Institute of Public Health and Environment, Incheon 22320, Korea
| | - Hojong Jun
- Department of Tropical Medicine and Parasitology, Inha University School of Medicine, Incheon 22212, Korea
| | - Seo Hye Park
- Department of Tropical Medicine and Parasitology, Inha University School of Medicine, Incheon 22212, Korea
| | - Bo-Young Jeon
- Department of Biomedical Laboratory Science, College of Health Sciences, Yonsei University, School of Public Health, Wonju 26493, Korea
| | - Jhang Ho Pak
- Department of Convergence Medicine, University of Ulsan, College of Medicine, Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Korea
| | - Young Yil Bakh
- Department of Biotechnology, Konkuk University, Chungju 27478, Korea
| | - Tong-Soo Kim
- Department of Tropical Medicine and Parasitology, Inha University School of Medicine, Incheon 22212, Korea
| | - Hyeong-Woo Lee
- Institute of Research and Development, Scorpiogen Co., Anseong 17579, Korea
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27
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Vernekar SKV, Tang J, Wu B, Huber AD, Casey MC, Myshakina N, Wilson DJ, Kankanala J, Kirby KA, Parniak MA, Sarafianos SG, Wang Z. Double-Winged 3-Hydroxypyrimidine-2,4-diones: Potent and Selective Inhibition against HIV-1 RNase H with Significant Antiviral Activity. J Med Chem 2017; 60:5045-5056. [PMID: 28525279 DOI: 10.1021/acs.jmedchem.7b00440] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human immunodeficiency virus (HIV) reverse transcriptase (RT)-associated ribonuclease H (RNase H) remains the only virally encoded enzymatic function yet to be exploited as an antiviral target. One of the possible challenges may be that targeting HIV RNase H is confronted with a steep substrate barrier. We have previously reported a 3-hydroxypyrimidine-2,4-dione (HPD) subtype that potently and selectively inhibited RNase H without inhibiting HIV in cell culture. We report herein a critical redesign of the HPD chemotype featuring an additional wing at the C5 position that led to drastically improved RNase H inhibition and significant antiviral activity. Structure-activity relationship (SAR) concerning primarily the length and flexibility of the two wings revealed important structural features that dictate the potency and selectivity of RNase H inhibition as well as the observed antiviral activity. Our current medicinal chemistry data also revealed that the RNase H biochemical inhibition largely correlated the antiviral activity.
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Affiliation(s)
- Sanjeev Kumar V Vernekar
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Jing Tang
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Bulan Wu
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Andrew D Huber
- Department of Veterinary Pathobiology, Christopher S. Bond Life Sciences Center, University of Missouri , Columbia, Missouri 65211, United States
| | - Mary C Casey
- Department of Molecular Microbiology and Immunology, Christopher S. Bond Life Sciences Center, University of Missouri School of Medicine , Columbia, Missouri 65211, United States
| | - Nataliya Myshakina
- Department of Natural Science, Chatham University , 1 Woodland Road, Pittsburgh, Pennsylvania 15232, United States
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Jayakanth Kankanala
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Karen A Kirby
- Department of Molecular Microbiology and Immunology, Christopher S. Bond Life Sciences Center, University of Missouri School of Medicine , Columbia, Missouri 65211, United States
| | - Michael A Parniak
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15219, United States
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology, Christopher S. Bond Life Sciences Center, University of Missouri School of Medicine , Columbia, Missouri 65211, United States.,Department of Biochemistry, University of Missouri , Columbia, Missouri 65211, United States
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
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28
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Tang J, Vernekar SKV, Chen YL, Miller L, Huber AD, Myshakina N, Sarafianos SG, Parniak MA, Wang Z. Synthesis, biological evaluation and molecular modeling of 2-Hydroxyisoquinoline-1,3-dione analogues as inhibitors of HIV reverse transcriptase associated ribonuclease H and polymerase. Eur J Med Chem 2017; 133:85-96. [PMID: 28384548 DOI: 10.1016/j.ejmech.2017.03.059] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/21/2017] [Accepted: 03/24/2017] [Indexed: 12/12/2022]
Abstract
Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) remains the only virally encoded enzymatic function not clinically validated as an antiviral target. 2-Hydroxyisoquinoline-1,3-dione (HID) is known to confer active site directed inhibition of divalent metal-dependent enzymatic functions, such as HIV RNase H, integrase (IN) and hepatitis C virus (HCV) NS5B polymerase. We report herein the synthesis and biochemical evaluation of a few C-5, C-6 or C-7 substituted HID subtypes as HIV RNase H inhibitors. Our data indicate that while some of these subtypes inhibited both the RNase H and polymerase (pol) functions of RT, potent and selective RNase H inhibition was achieved with subtypes 8-9 as exemplified with compounds 8c and 9c.
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Affiliation(s)
- Jing Tang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Sanjeev Kumar V Vernekar
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yue-Lei Chen
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Lena Miller
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Andrew D Huber
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA
| | - Nataliya Myshakina
- Department of Natural Science, Chatham University, 1 Woodland Road, Pittsburgh, PA 15232, USA
| | - Stefan G Sarafianos
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA; Department of Molecular Microbiology & Immunology, University of Missouri School of Medicine, Columbia, MO 65211, USA; Department of Biochemistry, University of Missouri, Columbia, MO 65211, USA
| | - Michael A Parniak
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA.
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29
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Hara RI, Maeda Y, Sakamoto T, Wada T. Double-stranded RNA-binding artificial cationic oligosaccharides stabilizing siRNAs with a low N/P ratio. Org Biomol Chem 2017; 15:1710-1717. [PMID: 28138666 DOI: 10.1039/c6ob02690g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Novel double-stranded RNA (dsRNA)-binding molecules were developed for the effective thermodynamic and biological stabilization of nucleic acids including short interfering RNAs (siRNAs). β-(1→4)-Linked-2,6-diamino-2,6-dideoxy-d-galactopyranose oligomers (ODAGals) were synthesized for this purpose, and their binding ability with dsRNAs was evaluated. Fluorescence anisotropy measurements showed the 3mer and 4mer of ODAGals to be strongly bound (Kd < 0.02 μM). The UV melting experiments demonstrated that the binding of ODAGals to dsRNAs proceeded with significant thermodynamic stabilization of the duplexes. Furthermore, the 4mer of ODAGal was clearly revealed to almost completely protect siRNAs with a low N/P ratio (i.e., N in the oligocationic molecule to P in the siRNA ratio) from cleavage by RNase A. On the basis of these results, ODAGals can serve as promising stabilizers or carriers of dsRNA-based drugs such as RNAi drugs.
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Affiliation(s)
- Rintaro Iwata Hara
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
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30
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Tang J, Kirby KA, Huber AD, Casey MC, Ji J, Wilson DJ, Sarafianos SG, Wang Z. 6-Cyclohexylmethyl-3-hydroxypyrimidine-2,4-dione as an inhibitor scaffold of HIV reverase transcriptase: Impacts of the 3-OH on inhibiting RNase H and polymerase. Eur J Med Chem 2017; 128:168-179. [PMID: 28182989 DOI: 10.1016/j.ejmech.2017.01.041] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 01/25/2017] [Accepted: 01/27/2017] [Indexed: 01/24/2023]
Abstract
3-Hydroxypyrimidine-2,4-dione (HPD) represents a versatile chemical core in the design of inhibitors of human immunodeficiency virus (HIV) reverse transcriptase (RT)-associated RNase H and integrase strand transfer (INST). We report herein the design, synthesis and biological evaluation of an HPD subtype (4) featuring a cyclohexylmethyl group at the C-6 position. Antiviral testing showed that most analogues of 4 inhibited HIV-1 in the low nanomolar to submicromolar range, without cytotoxicity at concentrations up to 100 μM. Biochemically, these analogues dually inhibited both the polymerase (pol) and the RNase H functions of RT, but not INST. Co-crystal structure of 4a with RT revealed a nonnucleoside RT inhibitor (NNRTI) binding mode. Interestingly, chemotype 11, the synthetic precursor of 4 lacking the 3-OH group, did not inhibit RNase H while potently inhibiting pol. By virtue of the potent antiviral activity and biochemical RNase H inhibition, HPD subtype 4 could provide a viable platform for eventually achieving potent and selective RNase H inhibition through further medicinal chemistry.
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Affiliation(s)
- Jing Tang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Karen A Kirby
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
| | - Andrew D Huber
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
| | - Mary C Casey
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
| | - Juan Ji
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, USA
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN 55455, USA.
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31
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D'Erasmo MP, Masaoka T, Wilson JA, Hunte EM, Beutler JA, Le Grice SFJ, Murelli RP. Traceless Solid-Phase α-Hydroxytropolone Synthesis. MEDCHEMCOMM 2016; 7:1789-1792. [PMID: 28090282 DOI: 10.1039/c6md00237d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
α-Hydroxytropolones are established inhibitors of several therapeutically relevant binuclear metalloenzymes, and thus lead drug targets for various human diseases. We have leveraged a recently-disclosed three-component oxidopyrylium cycloaddition in the first solid-phase synthesis of α-hydroxytropolones. We also showed that, while minor impurities exist after cleavage and aqueous wash, the semi-crude products display activity in HIV RT-associated RNaseH enzymatic and cell-based assays consistent with pure molecules made in solution phase. These proof-of-principle studies demonstrate the feasibility of solid-phase α-hydroxytropolone synthesis and its potential to serve as a powerful platform for α-hydroxytropolone-based drug discovery and development.
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Affiliation(s)
- Michael P D'Erasmo
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Takashi Masaoka
- Basic Research Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Jennifer A Wilson
- Molecular Targets Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Errol M Hunte
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA
| | - John A Beutler
- Molecular Targets Laboratory, National Cancer Institute, Frederick, MD, USA
| | | | - Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
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32
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Murelli RP, D'Erasmo MP, Hirsch DR, Meck C, Masaoka T, Wilson JA, Zhang B, Pal RK, Gallicchio E, Beutler JA, Le Grice SFJ. Synthetic α-Hydroxytropolones as Inhibitors of HIV Reverse Transcriptase Ribonuclease H Activity. MEDCHEMCOMM 2016; 7:1783-1788. [PMID: 28093576 PMCID: PMC5234084 DOI: 10.1039/c6md00238b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
HIV Reverse Transcriptase-associated ribonuclease H activity is a promising enzymatic target for drug development that has not been successfully targeted in the clinic. While the α-hydroxytropolone-containing natural products β-thujaplicinol and manicol have emerged as some of the most potent leads described to date, structure-function studies have been limited to the natural products and semi-synthetic derivatives of manicol. Thus, a library of α-hydroxytropolones synthesized through a convenient oxidopyrylium cycloaddition/ring-opening sequence have been tested in in vitro and cell-based assays, and have been analyzed using computational support. These studies reveal new synthetic α-hydroxytropolones that, unlike the natural product leads they are derived from, demonstrate protective antiviral activity in cellular assays.
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Affiliation(s)
- Ryan P Murelli
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Michael P D'Erasmo
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Danielle R Hirsch
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Christine Meck
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Takashi Masaoka
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Jennifer A Wilson
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Baofeng Zhang
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA
| | - Rajat K Pal
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Biochemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - Emilio Gallicchio
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, New York, USA; PhD Program in Chemistry, The Graduate Center of The City University of New York, New York, NY, USA; PhD Program in Biochemistry, The Graduate Center of The City University of New York, New York, NY, USA
| | - John A Beutler
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Stuart F J Le Grice
- Basic Research Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
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33
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Wu B, Tang J, Wilson DJ, Huber AD, Casey MC, Ji J, Kankanala J, Xie J, Sarafianos SG, Wang Z. 3-Hydroxypyrimidine-2,4-dione-5-N-benzylcarboxamides Potently Inhibit HIV-1 Integrase and RNase H. J Med Chem 2016; 59:6136-48. [PMID: 27283261 DOI: 10.1021/acs.jmedchem.6b00040] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Resistance selection by human immunodeficiency virus (HIV) toward known drug regimens necessitates the discovery of structurally novel antivirals with a distinct resistance profile. On the basis of our previously reported 3-hydroxypyrimidine-2,4-dione (HPD) core, we have designed and synthesized a new integrase strand transfer (INST) inhibitor type featuring a 5-N-benzylcarboxamide moiety. Significantly, the 6-alkylamino variant of this new chemotype consistently conferred low nanomolar inhibitory activity against HIV-1. Extended antiviral testing against a few raltegravir-resistant HIV-1 clones revealed a resistance profile similar to that of the second generation INST inhibitor (INSTI) dolutegravir. Although biochemical testing and molecular modeling also strongly corroborate the inhibition of INST as the antiviral mechanism of action, selected antiviral analogues also potently inhibited reverse transcriptase (RT) associated RNase H, implying potential dual target inhibition. In vitro ADME assays demonstrated that this novel chemotype possesses largely favorable physicochemical properties suitable for further development.
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Affiliation(s)
- Bulan Wu
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Jing Tang
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Andrew D Huber
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, Christopher S. Bond Life Sciences Center, University of Missouri , Columbia, Missouri 65211, United States
| | - Mary C Casey
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, Christopher S. Bond Life Sciences Center, University of Missouri , Columbia, Missouri 65211, United States
| | - Juan Ji
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, Christopher S. Bond Life Sciences Center, University of Missouri , Columbia, Missouri 65211, United States
| | - Jayakanth Kankanala
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Jiashu Xie
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, Christopher S. Bond Life Sciences Center, University of Missouri , Columbia, Missouri 65211, United States
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
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34
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Kankanala J, Kirby KA, Liu F, Miller L, Nagy E, Wilson DJ, Parniak MA, Sarafianos SG, Wang Z. Design, Synthesis, and Biological Evaluations of Hydroxypyridonecarboxylic Acids as Inhibitors of HIV Reverse Transcriptase Associated RNase H. J Med Chem 2016; 59:5051-62. [PMID: 27094954 DOI: 10.1021/acs.jmedchem.6b00465] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Targeting the clinically unvalidated reverse transcriptase (RT) associated ribonuclease H (RNase H) for human immunodeficiency virus (HIV) drug discovery generally entails chemotypes capable of chelating two divalent metal ions in the RNase H active site. The hydroxypyridonecarboxylic acid scaffold has been implicated in inhibiting homologous HIV integrase (IN) and influenza endonuclease via metal chelation. We report herein the design, synthesis, and biological evaluations of a novel variant of the hydroxypyridonecarboxylic acid scaffold featuring a crucial N-1 benzyl or biarylmethyl moiety. Biochemical studies show that most analogues consistently inhibited HIV RT-associated RNase H in the low micromolar range in the absence of significant inhibition of RT polymerase or IN. One compound showed reasonable cell-based antiviral activity (EC50 = 10 μM). Docking and crystallographic studies corroborate favorable binding to the active site of HIV RNase H, providing a basis for the design of more potent analogues.
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Affiliation(s)
- Jayakanth Kankanala
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Karen A Kirby
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center , Columbia, Missouri 65211, United States
| | - Feng Liu
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Lena Miller
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15219, United States
| | - Eva Nagy
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15219, United States
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Michael A Parniak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15219, United States
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center , Columbia, Missouri 65211, United States
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
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35
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Katano Y, Hisayoshi T, Kuze I, Okano H, Ito M, Nishigaki K, Takita T, Yasukawa K. Expression of moloney murine leukemia virus reverse transcriptase in a cell-free protein expression system. Biotechnol Lett 2016; 38:1203-11. [PMID: 27053084 DOI: 10.1007/s10529-016-2097-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 03/31/2016] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To characterize Moloney murine leukemia virus (MMLV) reverse transcriptases (RTs) expressed in a cell-free system and in Escherichia coli. RESULTS We previously expressed MMLV RT using an E. coli expression system and generated a highly thermostable quadruple variant MM4 (E286R/E302K/L435R/D524A) by site-directed mutagenesis. In this study, we expressed the wild-type MMLV RT (WT) and MM4 using a cell-free protein expression system from insect cells. WT exhibited DNA polymerase and RNase H activities, while MM4, in which the catalytic residue for RNase H activity, Asp524 is changed into Ala, exhibited only DNA polymerase activity. MM4, when held at 60 °C for 10 min, retained DNA polymerase activity, while WT, held at 54 °C for 10 min, lost this activity. In the cDNA synthesis reaction (0.5 μl) in which WT or MM4 were exposed to various temperatures and amounts of target RNA in a microarray chip, MM4 exhibited higher thermostability than WT. CONCLUSION MMLV RT expressed in the cell-free system is indistinguishable from that expressed in E. coli.
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Affiliation(s)
- Yuta Katano
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Tetsuro Hisayoshi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Ikumi Kuze
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Hiroyuki Okano
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Masaaki Ito
- Okinawa National College of Technology, Nago, Japan
| | - Koichi Nishigaki
- Saitama-Bio-Monodukuri-Network Research Organization, Saitama University, Saitama, Japan.,National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
| | - Teisuke Takita
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kiyoshi Yasukawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
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36
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Tang J, Liu F, Nagy E, Miller L, Kirby KA, Wilson DJ, Wu B, Sarafianos SG, Parniak MA, Wang Z. 3-Hydroxypyrimidine-2,4-diones as Selective Active Site Inhibitors of HIV Reverse Transcriptase-Associated RNase H: Design, Synthesis, and Biochemical Evaluations. J Med Chem 2016; 59:2648-59. [PMID: 26927866 DOI: 10.1021/acs.jmedchem.5b01879] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human immunodeficiency virus (HIV) reverse transcriptase (RT) associated ribonuclease H (RNase H) remains an unvalidated antiviral target. A major challenge of specifically targeting HIV RNase H arises from the general lack of selectivity over RT polymerase (pol) and integrase (IN) strand transfer (ST) inhibitions. We report herein the synthesis and biochemical evaluations of three novel 3-hydroxypyrimidine-2,4-dione (HPD) subtypes carefully designed to achieve selective RNase H inhibition. Biochemical studies showed the two subtypes with an N-1 methyl group (9 and 10) inhibited RNase H in low micromolar range without significantly inhibiting RT polymerase, whereas the N-1 unsubstituted subtype 11 inhibited RNase H in submicromolar range and RT polymerase in low micromolar range. Subtype 11 also exhibited substantially reduced inhibition in the HIV-1 INST assay and no significant cytotoxicity in the cell viability assay, suggesting that it may be amenable to further structure-activity relationship (SAR) for identifying RNase H inhibitors with antiviral activity.
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Affiliation(s)
- Jing Tang
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Feng Liu
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Eva Nagy
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15219, United States
| | - Lena Miller
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15219, United States
| | - Karen A Kirby
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine , Christopher S. Bond Life Sciences Center, Columbia, Missouri 65211, United States
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Bulan Wu
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Stefan G Sarafianos
- Department of Molecular Microbiology and Immunology and Department of Biochemistry, University of Missouri School of Medicine , Christopher S. Bond Life Sciences Center, Columbia, Missouri 65211, United States
| | - Michael A Parniak
- Department of Microbiology & Molecular Genetics, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania 15219, United States
| | - Zhengqiang Wang
- Center for Drug Design, Academic Health Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
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37
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Iwata R, Doi A, Maeda Y, Wada T. Synthesis of oligodiaminomannoses and analysis of their RNA duplex binding properties and their potential application as siRNA-based drugs. Org Biomol Chem 2015; 13:9504-15. [PMID: 26256756 DOI: 10.1039/c5ob01384d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis of artificial cationic oligodiaminosaccharides, α-(1 → 4)-linked-2,6-diamino-2,6-dideoxy-d-mannopyranose oligomers (ODAMans), and their interactions with RNA duplexes are described. The monomer through the pentamer, all of which bear unnatural 2,6-diaminomannose moieties, were successfully prepared. UV melting and fluorescence anisotropy analyses revealed that the ODAMans bound and thermodynamically stabilized both 12mer RNA duplexes and an siRNA. Furthermore, it was clearly shown that the siRNA acquired substantial RNase A resistance due to its binding to the ODAMan 4mer.
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Affiliation(s)
- Rintaro Iwata
- Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan.
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Identification of mechanistically distinct inhibitors of HIV-1 reverse transcriptase through fragment screening. Proc Natl Acad Sci U S A 2015; 112:6979-84. [PMID: 26038551 DOI: 10.1073/pnas.1423900112] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Fragment-based screening methods can be used to discover novel active site or allosteric inhibitors for therapeutic intervention. Using saturation transfer difference (STD) NMR and in vitro activity assays, we have identified fragment-sized inhibitors of HIV-1 reverse transcriptase (RT) with distinct chemical scaffolds and mechanisms compared to nonnucleoside RT inhibitors (NNRTIs) and nucleoside/nucleotide RT inhibitors (NRTIs). Three compounds were found to inhibit RNA- and DNA-dependent DNA polymerase activity of HIV-1 RT in the micromolar range while retaining potency against RT variants carrying one of three major NNRTI resistance mutations: K103N, Y181C, or G190A. These compounds also inhibit Moloney murine leukemia virus RT but not the Klenow fragment of Escherichia coli DNA polymerase I. Steady-state kinetic analyses demonstrate that one of these fragments is a competitive inhibitor of HIV-1 RT with respect to deoxyribonucleoside triphosphate (dNTP) substrate, whereas a second compound is a competitive inhibitor of RT polymerase activity with respect to the DNA template/primer (T/P), and consequently also inhibits RNase H activity. The dNTP competing RT inhibitor retains activity against the NRTI-resistant mutants K65R and M184V, demonstrating a drug resistance profile distinct from the nucleotide competing RT inhibitors indolopyridone-1 (INDOPY-1) and 4-dimethylamino-6-vinylpyrimidine-1 (DAVP-1). In antiviral assays, the T/P competing compound inhibits HIV-1 replication at a step consistent with an RT inhibitor. Screening of additional structurally related compounds to the three fragments led to the discovery of molecules with improved potency against HIV-1 RT. These fragment inhibitors represent previously unidentified scaffolds for development of novel drugs for HIV-1 prevention or treatment.
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Nishimura K, Yokokawa K, Hisayoshi T, Fukatsu K, Kuze I, Konishi A, Mikami B, Kojima K, Yasukawa K. Preparation and characterization of the RNase H domain of Moloney murine leukemia virus reverse transcriptase. Protein Expr Purif 2015; 113:44-50. [PMID: 25959458 DOI: 10.1016/j.pep.2015.04.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 03/31/2015] [Accepted: 04/14/2015] [Indexed: 10/23/2022]
Abstract
Moloney murine leukemia virus reverse transcriptase (MMLV RT) contains fingers, palm, thumb, and connection subdomains as well as an RNase H domain. The DNA polymerase active site resides in the palm subdomain, and the RNase H active site is located in the RNase H domain. The RNase H domain contains a positively charged α-helix called the C helix (H(594)GEIYRRR(601)), that is thought to be involved in substrate recognition. In this study, we expressed three versions of the RNase H domain in Escherichia coli, the wild-type domain (WT) (residues Ile498-Leu671) and two variants that lack the regions containing the C helix (Ile593-Leu603 and Gly595-Thr605, which we called ΔC1 and ΔC2, respectively) with a strep-tag at the N-terminus and a deca-histidine tag at the C-terminus. These peptides were purified from the cells by anion-exchange, Ni(2+) affinity, and Strep-Tactin affinity column chromatography, and then the tags were removed by proteolysis. In an RNase H assay using a 25-bp RNA-DNA heteroduplex, WT, ΔC1, and ΔC2 produced RNA fragments ranging from 7 to 16 nucleotides (nt) whereas the full-length MMLV RT (Thr24-Leu671) produced 14-20-nt RNA fragments, suggesting that elimination of the fingers, palm, thumb, and connection subdomains affects the binding of the RNase H domain to the RNA-DNA heteroduplex. The activity levels of WT, ΔC1, and ΔC2 were estimated to be 1%, 0.01%, and 0.01% of full-length MMLV RT activity, indicating that the C helix is important, but not critical, for the activity of the isolated RNase H domain.
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Affiliation(s)
- Kosaku Nishimura
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kanta Yokokawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Tetsuro Hisayoshi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kosuke Fukatsu
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Ikumi Kuze
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Atsushi Konishi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Bunzo Mikami
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Kenji Kojima
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Kiyoshi Yasukawa
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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40
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Jadaun A, Sudhakar D R, Subbarao N, Dixit A. In silico screening for novel inhibitors of DNA polymerase III alpha subunit of Mycobacterium tuberculosis (MtbDnaE2, H37Rv). PLoS One 2015; 10:e0119760. [PMID: 25811866 PMCID: PMC4374717 DOI: 10.1371/journal.pone.0119760] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 01/15/2015] [Indexed: 01/19/2023] Open
Abstract
Tuberculosis, a pandemic disease is caused by Mycobacterium tuberculosis (Mtb). DNA polymerase III encoded by DnaE2 of Mtb is specifically required for its survival in vivo, and hence can be considered to be a potential drug target. Amino acid sequence analysis of the MtbDnaE2 and its human counterpart does not show any significant similarity. Therefore, a 3D model of the MtbDnaE2 was generated using Modeller 9v10 with the template structure of E. Coli DNA polymerase III alpha subunit (2HNH_A). The generated models were validated using a number of programmes such as RAMPAGE/PROCHECK, VERIFY_3D, and ProSA. MtbDnaE2 has few conserved residues and four conserved domains similar to that present in DNA polymerase III of E. coli. In silico screening was performed with bioactive anti-tuberculosis compounds and 6-AU (a known inhibitor of DNA polymerase III of Bacillus subtilis) and its analogues against the modeled MtbDnaE2 structure. Docking was performed using GOLD v5.2 software which resulted in the identification of top ten compounds with high GOLD fitness scores and binding affinity (X-Score). To further evaluate the efficacy of these compounds, in silico ADMET analysis was performed using MedChem Designer v3. Given their high binding affinity to the targeted MtbDnaE2, which is essential for DNA replication in the Mtb and good ADMET properties, these compounds are promising candidates for further evaluation and development as anti-tubercular agents.
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Affiliation(s)
- Alka Jadaun
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Raja Sudhakar D
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - N. Subbarao
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Aparna Dixit
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
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41
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Bernard MA, Wang L, Tachado SD. DICER-ARGONAUTE2 complex in continuous fluorogenic assays of RNA interference enzymes. PLoS One 2015; 10:e0120614. [PMID: 25793518 PMCID: PMC4368098 DOI: 10.1371/journal.pone.0120614] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 02/05/2015] [Indexed: 12/30/2022] Open
Abstract
Mechanistic studies of RNA processing in the RNA-Induced Silencing Complex (RISC) have been hindered by lack of methods for continuous monitoring of enzymatic activity. “Quencherless” fluorogenic substrates of RNAi enzymes enable continuous monitoring of enzymatic reactions for detailed kinetics studies. Recombinant RISC enzymes cleave the fluorogenic substrates targeting human thymidylate synthase (TYMS) and hypoxia-inducible factor 1-α subunit (HIF1A). Using fluorogenic dsRNA DICER substrates and fluorogenic siRNA, DICER+ARGONAUTE2 mixtures exhibit synergistic enzymatic activity relative to either enzyme alone, and addition of TRBP does not enhance the apparent activity. Titration of AGO2 and DICER in enzyme assays suggests that AGO2 and DICER form a functional high-affinity complex in equimolar ratio. DICER and DICER+AGO2 exhibit Michaelis-Menten kinetics with DICER substrates. However, AGO2 cannot process the fluorogenic siRNA without DICER enzyme, suggesting that AGO2 cannot self-load siRNA into its active site. The DICER+AGO2 combination processes the fluorogenic siRNA substrate (Km=74 nM) with substrate inhibition kinetics (Ki=105 nM), demonstrating experimentally that siRNA binds two different sites that affect Dicing and AGO2-loading reactions in RISC. This result suggests that siRNA (product of DICER) bound in the active site of DICER may undergo direct transfer (as AGO2 substrate) to the active site of AGO2 in the DICER+AGO2 complex. Competitive substrate assays indicate that DICER+AGO2 cleavage of fluorogenic siRNA is specific, since unlabeled siRNA and DICER substrates serve as competing substrates that cause a concentration-dependent decrease in fluorescent rates. Competitive substrate assays of a series of DICER substrates in vitro were correlated with cell-based assays of HIF1A mRNA knockdown (log-log slope=0.29), suggesting that improved DICER substrate designs with 10-fold greater processing by the DICER+AGO2 complex can provide a strong (~2800-fold) improvement in potency for mRNA knockdown. This study lays the foundation of a systematic biochemical approach to optimize nucleic acid-based therapeutics for Dicing and ARGONAUTE2-loading for improving efficacy.
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Affiliation(s)
- Mark A. Bernard
- Department of Target Biology, Pfizer Oligonucleotide Therapeutics Unit, Cambridge South Campus, Cambridge, Massachusetts, United States of America
- Department of Protein Biology, Pfizer Global Biotherapeutics Technology Unit, Cambridge North Campus, Cambridge, Massachusetts, United States of America
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Leyu Wang
- Department of Target Biology, Pfizer Oligonucleotide Therapeutics Unit, Cambridge South Campus, Cambridge, Massachusetts, United States of America
| | - Souvenir D. Tachado
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
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42
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Ma J, Pawar RS, Grundel E, Mazzola EP, Ridge CD, Masaoka T, Le Grice SFJ, Wilson J, Beutler JA, Krynitsky AJ. Sesquiterpenoid tropolone glycosides from Liriosma ovata. JOURNAL OF NATURAL PRODUCTS 2015; 78:315-319. [PMID: 25587934 PMCID: PMC7709799 DOI: 10.1021/np5006696] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two new sesquiterpenoid tropolone glycosides, liriosmasides A (1) and B (2), along with two known compounds, secoxyloganin and oplopanpheside C, were isolated from a methanol extract of the roots of Liriosma ovata. The structures of 1 and 2 were elucidated by spectroscopic methods including 1D and 2D NMR and by high-resolution mass spectrometry involving an ultra-high-performance liquid chromatography-quadrupole-orbital ion trap mass spectrometric (UHPLC-Q-Orbitrap MS) method. Compound 1 showed weak inhibitory activity against HIV RNase H.
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Affiliation(s)
- Jun Ma
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Rahul S. Pawar
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Erich Grundel
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Eugene P. Mazzola
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Clark D. Ridge
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
| | - Takashi Masaoka
- RT Biochemistry Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - Stuart F. J. Le Grice
- RT Biochemistry Section, HIV Drug Resistance Program, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - Jennifer Wilson
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - John A. Beutler
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, Maryland 21702, United States
| | - Alexander J. Krynitsky
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, United States
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43
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Inhibition of the DNA polymerase and RNase H activities of HIV-1 reverse transcriptase and HIV-1 replication by Brasenia schreberi (Junsai) and Petasites japonicus (Fuki) components. J Nat Med 2015; 69:432-40. [PMID: 25663480 DOI: 10.1007/s11418-015-0885-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/31/2014] [Indexed: 01/22/2023]
Abstract
Human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) possesses two distinct enzymatic activities: those of RNA- and DNA-dependent DNA polymerases and RNase H. In the current HIV-1 therapy, all HIV-1 RT inhibitors inhibit the activity of DNA polymerase, but not that of RNase H. We previously reported that ethanol and water extracts of Brasenia schreberi (Junsai) inhibited the DNA polymerase activity of HIV-1 RT [Hisayoshi et al. (2014) J Biol Macromol 14:59-65]. In this study, we screened 43 edible plants and found that ethanol and water extracts of Brasenia schreberi and water extract of Petasites japonicus strongly inhibit not only the activity of DNA polymerase to incorporate dTTP into poly(rA)-p(dT)15 but also the activity of RNase H to hydrolyze the RNA strand of an RNA/DNA hybrid. In addition, these three extracts inhibit HIV-1 replication in human cells, with EC50 values of 1-2 µg/ml. These results suggest that Brasenia schreberi and Petasites japonicus contain substances that block HIV-1 replication by inhibiting the DNA polymerase activity and/or RNase H activity of HIV-1 RT.
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44
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Vernekar SKV, Liu Z, Nagy E, Miller L, Kirby KA, Wilson DJ, Kankanala J, Sarafianos SG, Parniak MA, Wang Z. Design, synthesis, biochemical, and antiviral evaluations of C6 benzyl and C6 biarylmethyl substituted 2-hydroxylisoquinoline-1,3-diones: dual inhibition against HIV reverse transcriptase-associated RNase H and polymerase with antiviral activities. J Med Chem 2014; 58:651-64. [PMID: 25522204 PMCID: PMC4306517 DOI: 10.1021/jm501132s] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Reverse transcriptase (RT) associated ribonuclease H (RNase H) remains the only virally encoded enzymatic function not targeted by current chemotherapy against human immunodeficiency virus (HIV). Although numerous chemotypes have been reported to inhibit HIV RNase H biochemically, few show significant antiviral activity against HIV. We report herein the design, synthesis, and biological evaluations of a novel variant of 2-hydroxyisoquinoline-1,3-dione (HID) scaffold featuring a crucial C-6 benzyl or biarylmethyl moiety. The synthesis involved a recently reported metal-free direct benzylation between tosylhydrazone and boronic acid, which allowed the generation of structural diversity for the hydrophobic aromatic region. Biochemical studies showed that the C-6 benzyl and biarylmethyl HID analogues, previously unknown chemotypes, consistently inhibited HIV RT-associated RNase H and polymerase with IC50s in low to submicromolar range. The observed dual inhibitory activity remained uncompromised against RT mutants resistant to non-nucleoside RT inhibitors (NNRTIs), suggesting the involvement of binding site(s) other than the NNRTI binding pocket. Intriguingly, these same compounds inhibited the polymerase, but not the RNase H function of Moloney Murine Leukemia Virus (MoMLV) RT and also inhibited Escherichia coli RNase H. Additional biochemical testing revealed a substantially reduced level of inhibition against HIV integrase. Molecular docking corroborates favorable binding of these analogues to the active site of HIV RNase H. Finally, a number of these analogues also demonstrated antiviral activity at low micromolar concentrations.
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Affiliation(s)
- Sanjeev Kumar V Vernekar
- Center for Drug Design, Academic Health Center, University of Minnesota , 516 Delaware Street SE, PWB 7-224, MMC 204 Minneapolis, Minnesota 55455, United States
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45
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Velthuisen EJ, Johns BA, Gerondelis P, Chen Y, Li M, Mou K, Zhang W, Seal JW, Hightower KE, Miranda SR, Brown K, Leesnitzer L. Pyridopyrimidinone inhibitors of HIV-1 RNase H. Eur J Med Chem 2014; 83:609-16. [DOI: 10.1016/j.ejmech.2014.06.061] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/25/2014] [Accepted: 06/27/2014] [Indexed: 01/13/2023]
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46
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Himmel DM, Myshakina NS, Ilina T, Van Ry A, Ho WC, Parniak MA, Arnold E. Structure of a dihydroxycoumarin active-site inhibitor in complex with the RNase H domain of HIV-1 reverse transcriptase and structure-activity analysis of inhibitor analogs. J Mol Biol 2014; 426:2617-31. [PMID: 24840303 DOI: 10.1016/j.jmb.2014.05.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/08/2014] [Accepted: 05/12/2014] [Indexed: 11/28/2022]
Abstract
Human immunodeficiency virus (HIV) encodes four essential enzymes: protease, integrase, reverse transcriptase (RT)-associated DNA polymerase, and RT-associated ribonuclease H (RNase H). Current clinically approved anti-AIDS drugs target all HIV enzymatic activities except RNase H, which has proven to be a very difficult target for HIV drug discovery. Our high-throughput screening activities identified the dihydroxycoumarin compound F3284-8495 as a specific inhibitor of RT RNase H, with low micromolar potency in vitro. Optimization of inhibitory potency can be facilitated by structural information about inhibitor-target binding. Here, we report the crystal structure of F3284-8495 bound to the active site of an isolated RNase H domain of HIV-1 RT at a resolution limit of 1.71Å. From predictions based on this structure, compounds were obtained that showed improved inhibitory activity. Computational analysis suggested structural alterations that could provide additional interactions with RT and thus improve inhibitory potency. These studies established proof of concept that F3284-8495 could be used as a favorable chemical scaffold for development of HIV RNase H inhibitors.
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Affiliation(s)
- Daniel M Himmel
- Center for Advanced Biotechnology and Medicine and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854-5627, USA.
| | - Nataliya S Myshakina
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
| | - Tatiana Ilina
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
| | - Alexander Van Ry
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
| | - William C Ho
- Center for Advanced Biotechnology and Medicine and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854-5627, USA.
| | - Michael A Parniak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
| | - Eddy Arnold
- Center for Advanced Biotechnology and Medicine and Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ 08854-5627, USA.
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47
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Ilina T, LaBarge K, Sarafianos SG, Ishima R, Parniak MA. Inhibitors of HIV-1 Reverse Transcriptase-Associated Ribonuclease H Activity. BIOLOGY 2014; 1:521-41. [PMID: 23599900 PMCID: PMC3627382 DOI: 10.3390/biology1030521] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
HIV-1 enzyme reverse transcriptase (RT) is a major target for antiviral drug development, with over half of current FDA-approved therapeutics against HIV infection targeting the DNA polymerase activity of this enzyme. HIV-1 RT is a multifunctional enzyme that has RNA and DNA dependent polymerase activity, along with ribonuclease H (RNase H) activity. The latter is responsible for degradation of the viral genomic RNA template during first strand DNA synthesis to allow completion of reverse transcription and the viral dsDNA. While the RNase H activity of RT has been shown to be essential for virus infectivity, all currently used drugs directed at RT inhibit the polymerase activity of the enzyme; none target RNase H. In the last decade, the increasing prevalence of HIV variants resistant to clinically used antiretrovirals has stimulated the search for inhibitors directed at stages of HIV replication different than those targeted by current drugs. HIV RNase H is one such novel target and, over the past few years, significant progress has been made in identifying and characterizing new RNase H inhibitor pharmacophores. In this review we focus mainly on the most potent low micromolar potency compounds, as these provide logical bases for further development. We also discuss why HIV RNase H has been a difficult target for antiretroviral drug development.
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Affiliation(s)
- Tatiana Ilina
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, S.414, Pittsburgh, PA 15219, USA; (T.I.); (K.L.)
| | - Krystal LaBarge
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, S.414, Pittsburgh, PA 15219, USA; (T.I.); (K.L.)
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO, USA;
| | - Stefan G. Sarafianos
- Structural Biology, University of Pittsburgh School of Medicine, 450 Technology Drive, S.414, Pittsburgh, PA 15219, USA;
| | - Rieko Ishima
- Department of Molecular Microbiology & Immunology, University of Missouri, Columbia, MO, USA;
| | - Michael A. Parniak
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 450 Technology Drive, S.414, Pittsburgh, PA 15219, USA; (T.I.); (K.L.)
- Author to whom correspondence should be addressed; ; Tel.: +1-412-648-1927; Fax: +1-412-648-9653
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48
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Poongavanam V, Narayana Moorthy NSH, Kongsted J. Dual mechanism of HIV-1 integrase and RNase H inhibition by diketo derivatives – a computational study. RSC Adv 2014. [DOI: 10.1039/c4ra05728g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dual inhibition of HIV-1 integrase and RNase H by the diketo derivatives is investigated through ligand and structure based computational methods.
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Affiliation(s)
| | | | - Jacob Kongsted
- Department of Physics
- Chemistry and Pharmacy
- University of Southern Denmark
- Odense M, Denmark
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49
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Transient kinetic analyses of the ribonuclease H cleavage activity of HIV-1 reverse transcriptase in complex with efavirenz and/or a β-thujaplicinol analogue. Biochem J 2013; 455:179-84. [PMID: 23927736 DOI: 10.1042/bj20130850] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
EFV (efavirenz) and β-thujaplicinol [2,7-dihydroxy-4-1(methylethyl)-2,4,6-cycloheptatrien-1-one] have contrasting effects on the RNase H activity of HIV-1 RT (reverse transcriptase). EFV binds in the non-nucleoside inhibitor-binding pocket and accelerates this activity, whereas β-thujaplicinol binds in the RNase H active site and inhibits it. We have used pre-steady-state kinetic analyses to gain an insight into the mechanism by which EFV and a β-thujaplicinol analogue [19616 (2,7-dihydroxy-2,4,6-cyclo-heptatrien-1-one)] modulate RT RNase H activity. Our data show that EFV and 19616 have no effect on polymerase-dependent RNase H cleavages. However, both compounds significantly affected the rates of polymerase-independent RNase H cleavages. In regard to the latter, we found no evidence that the bound RNA/DNA template/primer substrate restricted 19616 from interacting with RT. In light of these data, we propose a model in which 19616 binds to the RNase H active site of RT after the primary polymerase-dependent RNase H cleavage has occurred and stabilizes the 3'-end of the DNA primer in the polymerase active site thus blocking the enzyme's ability to carry out the polymerase-independent cleavages. By contrast, EFV destabilizes the 3'-end of the DNA primer in the DNA polymerase active site and promotes RT-mediated polymerase-independent cleavages. Consistent with this model, we show antagonism between EFV and 19616.
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50
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Henrich CJ, Beutler JA. Matching the power of high throughput screening to the chemical diversity of natural products. Nat Prod Rep 2013; 30:1284-98. [PMID: 23925671 PMCID: PMC3801163 DOI: 10.1039/c3np70052f] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Covering up to 2013. Application of high throughput screening technologies to natural product samples demands alterations in assay design as well as sample preparation in order to yield meaningful hit structures at the end of the campaign.
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Affiliation(s)
- Curtis J. Henrich
- Basic Science Program, SAIC-Frederick, Inc. Frederick National Lab
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702 USA
| | - John A. Beutler
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702 USA
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