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Wright TH, Giurgiu C, Zhang W, Radakovic A, O'Flaherty DK, Zhou L, Szostak JW. Prebiotically Plausible "Patching" of RNA Backbone Cleavage through a 3'-5' Pyrophosphate Linkage. J Am Chem Soc 2019; 141:18104-18112. [PMID: 31651170 PMCID: PMC7577263 DOI: 10.1021/jacs.9b08237] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
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Achieving multiple cycles of RNA
replication within a model protocell
would be a critical step toward demonstrating a path from prebiotic
chemistry to cellular biology. Any model for early life based on an
“RNA world” must account for RNA strand cleavage and
hydrolysis, which would degrade primitive genetic information and
lead to an accumulation of truncated, phosphate-terminated strands.
We show here that cleavage of the phosphodiester backbone is not an
end point for RNA replication. Instead, 3′-phosphate-terminated
RNA strands can participate in template-directed copying reactions
with activated ribonucleotide monomers. These reactions form a pyrophosphate
linkage, the stability of which we have characterized in the context
of RNA copying chemistry. The presence of free magnesium cations results
in cleavage of the pyrophosphate bond within minutes. However, we
found that the pyrophosphate bond is relatively stable within an RNA
duplex and in the presence of chelated magnesium. We show that, under
these conditions, pyrophosphate-linked RNA can act as a template for
the polymerization of ribonucleotides into canonical 3′–5′
phosphodiester-linked RNA. We suggest that primer extension of 3′-phosphate-terminated
RNA followed by template-directed copying represents a plausible nonenzymatic
pathway for the salvage and recovery of genetic information following
strand cleavage.
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Affiliation(s)
- Tom H Wright
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , 185 Cambridge Street , Boston , Massachusetts 02114 , United States
| | - Constantin Giurgiu
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , 185 Cambridge Street , Boston , Massachusetts 02114 , United States
| | - Wen Zhang
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , 185 Cambridge Street , Boston , Massachusetts 02114 , United States
| | - Aleksandar Radakovic
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , 185 Cambridge Street , Boston , Massachusetts 02114 , United States
| | - Derek K O'Flaherty
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , 185 Cambridge Street , Boston , Massachusetts 02114 , United States
| | - Lijun Zhou
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , 185 Cambridge Street , Boston , Massachusetts 02114 , United States
| | - Jack W Szostak
- Howard Hughes Medical Institute, Department of Molecular Biology, and Center for Computational and Integrative Biology , Massachusetts General Hospital , 185 Cambridge Street , Boston , Massachusetts 02114 , United States
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2
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Abstract
Due to its high catalytic activity and readily available supply, ribonuclease A (RNase A) has become a pivotal enzyme in the history of protein science. Moreover, this great interest has carried over to computational chemistry and molecular dynamics, where RNase A has become a model system for various types of studies, all the while being an important drug design target in its own right. Here, we present a detailed molecular dynamics study of RNase–ligand binding involving 22 compounds, spanning nearly five orders of magnitude in affinity, and totaling 8.8 μs of sampling with the standard Amber parameters and an additional 8.8 μs of sampling with a modified potential. We show that short-lived, solvent-mediated bridging interactions are crucial to RNase–ligand binding. We characterize the behavior of bridging solvent molecules, uncovering a power-law dependence between the lifetime of a solvent bridge and the probability of its occurrence. We also demonstrate that from an energetic perspective, bridging solvent in RNase A–ligand binding behaves like part of the enzyme, rather than the ligands. Moreover, we describe an automated pipeline for the detection and processing of bridging interactions, and offer an independent assessment of the performance of the state-of-the-art fixed-charge force fields. Thus, our work has broad implications for drug design and computational chemistry in general.
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Affiliation(s)
- Stefan M. Ivanov
- Faculty of Pharmacy, Medical University of Sofia, Sofia, Bulgaria
- * E-mail:
| | - Ivan Dimitrov
- Faculty of Pharmacy, Medical University of Sofia, Sofia, Bulgaria
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3
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Abstract
Sulfonic nucleic acids were identified as inhibitors of ribonuclease A (RNase A). The incorporation of a strongly acidic group (sulfonic, -SO3H) at the 3'-end of pyrimidine nucleosides thymidine and uridine was prompted by the low inhibition constant (Ki) values recorded for carboxymethylsulfonyl (-SO2CH2CO2H) and -CO2H functionalized nucleosides. It was envisaged that the sulfonic acid-modified pyrimidines would bind effectively with the positively charged P1 site of ribonuclease A. Typical harsh conditions used for SO3H incorporation were replaced with milder reaction conditions. The uridine analogue showing a Ki value of 0.96 μM elicited a better result than the thymidine-modified inhibitor. Notably, it was also the best result among all modified non-phosphate acidic nucleosides reported and screened so far as RNase A inhibitors.
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Affiliation(s)
- Dhrubajyoti Datta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| | - Tanmaya Pathak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
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4
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Bafna K, Narayanan C, Chennubhotla SC, Doucet N, Agarwal PK. Nucleotide substrate binding characterization in human pancreatic-type ribonucleases. PLoS One 2019; 14:e0220037. [PMID: 31393891 PMCID: PMC6687278 DOI: 10.1371/journal.pone.0220037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 07/07/2019] [Indexed: 12/15/2022] Open
Abstract
Human genome contains a group of more than a dozen similar genes with diverse biological functions including antiviral, antibacterial and angiogenesis activities. The characterized gene products of this group show significant sequence similarity and a common structural fold associated with binding and cleavage of ribonucleic acid (RNA) substrates. Therefore, these proteins have been categorized as members of human pancreatic-type ribonucleases (hRNases). hRNases differ in cell/tissue localization and display distinct substrate binding preferences and a wide range of ribonucleolytic catalytic efficiencies. Limited information is available about structural and dynamical properties that influence this diversity among these homologous RNases. Here, we use computer simulations to characterize substrate interactions, electrostatics and dynamical properties of hRNases 1-7 associated with binding to two nucleotide substrates (ACAC and AUAU). Results indicate that even with complete conservation of active-site catalytic triad associated with ribonucleolytic activity, these enzymes show significant differences in substrate interactions. Detailed characterization suggests that in addition to binding site electrostatic and van der Waals interactions, dynamics of distal regions may also play a role in binding. Another key insight is that a small difference in temperature of 300 K (used in experimental studies) and 310 K (physiological temperature) shows significant changes in enzyme-substrate interactions.
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Affiliation(s)
- Khushboo Bafna
- Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Chitra Narayanan
- INRS-Institut Armand-Frappier, Université du Québec, Laval, Québec, Canada
| | - S. Chakra Chennubhotla
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Nicolas Doucet
- INRS-Institut Armand-Frappier, Université du Québec, Laval, Québec, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Structure, and Engineering, Université Laval, Québec, Quebec, Canada
| | - Pratul K. Agarwal
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee, United States of America
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5
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Kayet A, Datta D, Das A, Dasgupta S, Pathak T. 1,5-Disubstituted 1,2,3-triazole linked disaccharides: Metal-free syntheses and screening of a new class of ribonuclease A inhibitors. Bioorg Med Chem 2018; 26:455-462. [DOI: 10.1016/j.bmc.2017.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 11/28/2017] [Accepted: 12/02/2017] [Indexed: 10/18/2022]
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6
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Datta D, Mondal P, Dasgupta S, Pathak T. Acidic-Amino-Acid-Conjugated Dinucleosides as Ribonuclease A Inhibitors: Rational Design and Effect of Backbone Chirality on Enzyme Inhibition. ChemistrySelect 2017. [DOI: 10.1002/slct.201700253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Dhrubajyoti Datta
- Department of Chemistry; Indian Institute of Technology Kharagpur (IIT Kharagpur); Kharagpur 721302 India
| | - Pampa Mondal
- Department of Chemistry; Indian Institute of Technology Kharagpur (IIT Kharagpur); Kharagpur 721302 India
| | - Swagata Dasgupta
- Department of Chemistry; Indian Institute of Technology Kharagpur (IIT Kharagpur); Kharagpur 721302 India
| | - Tanmaya Pathak
- Department of Chemistry; Indian Institute of Technology Kharagpur (IIT Kharagpur); Kharagpur 721302 India
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7
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Datta D, Dasgupta S, Pathak T. Carboxymethylsulfonylated Ribopyrimidines: Rational Design of Ribonuclease A Inhibitors Employing Chemical Logic. ChemMedChem 2016; 11:620-8. [PMID: 26945688 DOI: 10.1002/cmdc.201600007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Indexed: 11/11/2022]
Abstract
Hydrolysis of RNA by ribonuclease A crucially depends on the participation of the 2'-OH group as well as the positioning of the internucleotide bond at two different sites of the enzyme. Therefore, ribopyrimidines were modified with -SO2CH2CO2H, an acidic functional group, which was expected to interact with the phosphate binding site. These ribonucleosides were designed to understand the influence of the 2'-OH group of these inhibitors on ribonuclease A inhibition along with the effect of the -SO2CH2CO2H group. The "down" configuration of the 2'-OH group enhanced the inhibitory properties (Ki =1.75 μm) and also imparted important Val43 H-bonding with the furanose oxygen atom of the inhibitors. One of the most important aspects of this work is that there was no serendipitous discovery of the inhibitors. The inhibitors reported in this manuscript were obtained by design by employing chemical logic.
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Affiliation(s)
- Dhrubajyoti Datta
- Department of Chemistry, Indian Institute of Technology (IIT)-Kharagpur, Kharagpur, 721302, India
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology (IIT)-Kharagpur, Kharagpur, 721302, India.
| | - Tanmaya Pathak
- Department of Chemistry, Indian Institute of Technology (IIT)-Kharagpur, Kharagpur, 721302, India.
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8
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Datta D, Dasgupta S, Pathak T. Ribonuclease A inhibition by carboxymethylsulfonyl-modified xylo- and arabinopyrimidines. ChemMedChem 2014; 9:2138-49. [PMID: 25125220 DOI: 10.1002/cmdc.201402179] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Indexed: 11/10/2022]
Abstract
A group of acidic nucleosides were synthesized to develop a new class of ribonuclease A (RNase A) inhibitors. Our recent study on carboxymethylsulfonyl-modified nucleosides revealed some interesting results in RNase A inhibition. This positive outcome triggered an investigation of the role played by secondary sugar hydroxy groups in inhibiting RNase A activity. Uridines and cytidines modified with SO2 CH2 COOH groups at the 2'- and 3'-positions show good inhibitory properties with low inhibition constant (Ki ) values in the range of 109-17 μM. The present work resulted in a set of inhibitors that undergo more effective interactions with the RNase A active site, as visualized by docking studies.
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Affiliation(s)
- Dhrubajyoti Datta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur (India), Fax: (+91) 3222-255303
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9
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Dutta S, Bandyopadhyay C, Bottero V, Veettil MV, Wilson L, Pins MR, Johnson KE, Warshall C, Chandran B. Angiogenin interacts with the plasminogen activation system at the cell surface of breast cancer cells to regulate plasmin formation and cell migration. Mol Oncol 2014; 8:483-507. [PMID: 24457100 DOI: 10.1016/j.molonc.2013.12.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 12/23/2013] [Accepted: 12/28/2013] [Indexed: 01/28/2023] Open
Abstract
Angiogenin (ANG), a 14-kDa pro-angiogenic secreted protein, has been shown to play a role in cell migration and tumor invasion, which involve proteolytic cleavage of plasminogen to generate plasmin. However, the mechanism by which ANG regulates plasmin formation and cell migration was not known. Our studies here detected elevated levels of secreted and cell surface-bound ANG in highly invasive metastatic breast cancer cells. ANG was also detected at very high levels in the tumor cells in infiltrating ductal carcinomas. By immunofluorescence and immunoprecipitation analysis, ANG was detected at the leading edges of the cell surfaces where it colocalized and interacted with members of the plasminogen activation system (PAS) such as annexin A2 (A2), calpactin (S100-A10) and urokinase plasminogen activator receptor (uPAR). Analysis of lipid raft (LR) and non-lipid raft (NLR) regions of the cell membranes showed the predominance of ANG, A2 and S100-A10 in the LR regions. In contrast, uPAR was detected predominantly in the NLR fractions, suggesting that ANG interacts with uPAR at the junctions of LR and NLR regions. ANG knockdown in T47D and MDA-MB-231 breast cancer cell lines did not affect the cellular expression of A2, S100-A10 and uPAR but decreased cell migration and plasmin formation. Neutralization of ANG with monoclonal antibodies similarly decreased the migration of MDA-MB-231 cells. In the presence of ANG, uPAR was observed to interact with uPA, which is necessary for plasmin formation. Conversely, in the absence of ANG, uPAR did not interact with uPA and FAK and Src kinases were observed to be dephosphorylated. Exogenous addition of recombinant ANG to ANG knocked down MDA-MB-231 cells restored FAK phosphorylation, uPAR interactions with uPA, plasmin formation as well as migration of these cells. Taken together, our results identified a novel role for ANG as a member of the uPAR interactome that facilitates the interaction of uPAR with uPA, leading to plasmin formation and cell migration necessary for tumor invasion and metastasis of breast cancer cells.
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Affiliation(s)
- Sujoy Dutta
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA.
| | - Chirosree Bandyopadhyay
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Virginie Bottero
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Mohanan V Veettil
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Lydia Wilson
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Michael R Pins
- Department of Pathology, Advocate Lutheran General Hospital, Park Ridge, IL, USA
| | - Karen E Johnson
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Case Warshall
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Bala Chandran
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
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10
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Debnath J, Dasgupta S, Pathak T. Dinucleosides with Non-Natural Backbones: A New Class of Ribonuclease A and Angiogenin Inhibitors. Chemistry 2012; 18:1618-27. [DOI: 10.1002/chem.201102816] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Indexed: 11/11/2022]
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11
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Holloway DE, Chavali GB, Leonidas DD, Baker MD, Acharya KR. Influence of naturally-occurring 5'-pyrophosphate-linked substituents on the binding of adenylic inhibitors to ribonuclease a: an X-ray crystallographic study. Biopolymers 2009; 91:995-1008. [PMID: 19191310 PMCID: PMC2816359 DOI: 10.1002/bip.21158] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 01/26/2009] [Accepted: 01/27/2009] [Indexed: 11/22/2022]
Abstract
Ribonuclease A is the archetype of a functionally diverse superfamily of vertebrate-specific ribonucleases. Inhibitors of its action have potential use in the elucidation of the in vivo roles of these enzymes and in the treatment of pathologies associated therewith. Derivatives of adenosine 5'-pyrophosphate are the most potent nucleotide-based inhibitors known. Here, we use X-ray crystallography to visualize the binding of four naturally-occurring derivatives that contain 5'-pyrophosphate-linked extensions. 5'-ATP binds with the adenine occupying the B(2) subsite in the manner of an RNA substrate but with the gamma-phosphate at the P(1) subsite. Diadenosine triphosphate (Ap(3)A) binds with the adenine in syn conformation, the beta-phosphate as the principal P(1) subsite ligand and without order beyond the gamma-phosphate. NADPH and NADP(+) bind with the adenine stacked against an alternative rotamer of His119, the 2'-phosphate at the P(1) subsite, and without order beyond the 5'-alpha-phosphate. We also present the structure of the complex formed with pyrophosphate ion. The structural data enable existing kinetic data on the binding of these compounds to a variety of ribonucleases to be rationalized and suggest that as the complexity of the 5'-linked extension increases, the need to avoid unfavorable contacts places limitations on the number of possible binding modes.
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Affiliation(s)
- Daniel E Holloway
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
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12
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Abstract
Organophosphate ester (OP) compounds are known for their ubiquitous use as insecticides. At the same time, these chemicals are highly toxic and can be used as nerve agents. G117H mutant of human Butyrylcholinesterase (BChE) was found to be capable of hydrolyzing certain OPs and protect against their toxicity. However, for therapeutic use, the rate of hydrolysis is too low. Its catalytic power can be improved by rational design, but the structure of the G117H mutant is first required. In this work, we determined, computationally, the three dimensional structure of the G117H BChE mutant. The structure was then validated by simulating acetylation of acetylthiocholine (ATC). Several plausible conformers of G117H BChE were examined but only the (62,-75) conformer fully reproduced catalytic effect. The (62,-75) conformer is, therefore, suggested as the structure adopted by the G117H BChE mutant. This conformer is shown to explain the loss of esterase activity observed for the G122H Acetylcholinesterase mutant together with its recovery when additional mutations are placed turning the enzyme also into an OP hydrolase. Furthermore, similarity of the structure to the structure of RNase A, which is known to hydrolyze the O--P bond in RNA, grants it further credibility and suggests a mechanism for the OP hydrolysis.
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Affiliation(s)
- Moshe Amitay
- Department of Medicinal Chemistry and Natural Products, The Lise Meitner-Minerva Center for Computational Quantum Chemistry, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
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Tsirkone VG, Dossi K, Drakou C, Zographos SE, Kontou M, Leonidas DD. Inhibitor design for ribonuclease A: the binding of two 5'-phosphate uridine analogues. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:671-7. [PMID: 19574636 PMCID: PMC2705631 DOI: 10.1107/s1744309109021423] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 06/05/2009] [Indexed: 11/10/2022]
Abstract
In the quest for the rational design of selective and potent inhibitors for members of the pancreatic ribonuclease A (RNase A) family of biomedical interest, the binding of uridine 5'-phosphate (U5P) and uridine 5'-diphosphate (UDP) to RNase A have been investigated using kinetic studies and X-ray crystallography. Both nucleotides are competitive inhibitors of the enzyme, with K(i) values of 4.0 and 0.65 mM, respectively. They bind to the active site of the enzyme by anchoring two molecules connected to each other by hydrogen bonds and van der Waals interactions. While the first of the inhibitor molecules binds with its nucleobase in the pyrimidinyl-binding subsite, the second is bound at the purine-preferring subsite. The unexpected binding of a pyrimidine at the purine-binding subsite has added new important elements to the rational design approach for the discovery of new potent inhibitors of the RNase A superfamily.
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Affiliation(s)
- Vicky G. Tsirkone
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Kyriaki Dossi
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Christina Drakou
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Spyros E. Zographos
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Maria Kontou
- Department of Biochemistry and Biotechnology, University of Thessaly, 26 Ploutonos St., 41221 Larissa, Greece
| | - Demetres D. Leonidas
- Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
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14
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Samanta A, Leonidas DD, Dasgupta S, Pathak T, Zographos SE, Oikonomakos NG. Morpholino, Piperidino, and Pyrrolidino Derivatives of Pyrimidine Nucleosides as Inhibitors of Ribonuclease A: Synthesis, Biochemical, and Crystallographic Evaluation,. J Med Chem 2009; 52:932-42. [DOI: 10.1021/jm800724t] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anirban Samanta
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India, and Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Demetres D. Leonidas
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India, and Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India, and Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Tanmaya Pathak
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India, and Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Spyros E. Zographos
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India, and Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
| | - Nikos G. Oikonomakos
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India, and Institute of Organic and Pharmaceutical Chemistry, National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece
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Larson SB, Day JS, Cudney R, McPherson A. A new crystal form of bovine pancreatic RNase A in complex with 2'-deoxyguanosine-5'-monophosphate. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:728-33. [PMID: 17768339 PMCID: PMC2376308 DOI: 10.1107/s1744309107039565] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Accepted: 08/09/2007] [Indexed: 11/11/2022]
Abstract
The structure of bovine pancreatic RNase A has been determined in complex with 2'-deoxyguanosine-5'-monophosphate (dGMP) at 1.33 A resolution at room temperature in a previously unreported unit cell belonging to space group P3(1). There are two molecules of nucleotide per enzyme molecule, one of which lies in the active-site cleft in the productive binding mode, whilst the guanine base of the other dGMP occupies the pyrimidine-specific binding site in a nonproductive mode such that it forms hydrogen bonds to the phosphate group of the first dGMP. This is the first RNase A structure containing a guanine base in the B2 binding site. Each dGMP molecule is involved in intermolecular interactions with adjacent RNase A molecules in the lattice and the two nucleotides appear to direct the formation of the crystal lattice. Because GMP may be produced during degradation of RNA, this association could represent an inhibitor complex and thereby affect the observed enzyme kinetics.
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Affiliation(s)
- Steven B. Larson
- Department of Molecular Biology and Biochemistry, The University of California, Irvine, CA 92697-3900, USA
| | - John S. Day
- Department of Molecular Biology and Biochemistry, The University of California, Irvine, CA 92697-3900, USA
| | | | - Alexander McPherson
- Department of Molecular Biology and Biochemistry, The University of California, Irvine, CA 92697-3900, USA
- Correspondence e-mail:
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Polydoridis S, Leonidas DD, Oikonomakos NG, Archontis G. Recognition of ribonuclease A by 3'-5'-pyrophosphate-linked dinucleotide inhibitors: a molecular dynamics/continuum electrostatics analysis. Biophys J 2007; 92:1659-72. [PMID: 17142283 PMCID: PMC1796809 DOI: 10.1529/biophysj.106.093419] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Accepted: 11/01/2006] [Indexed: 11/18/2022] Open
Abstract
The proteins of the pancreatic ribonuclease A (RNase A) family catalyze the cleavage of the RNA polymer chain. The development of RNase inhibitors is of significant interest, as some of these compounds may have a therapeutic effect in pathological conditions associated with these proteins. The most potent low molecular weight inhibitor of RNase reported to date is the compound 5'-phospho-2'-deoxyuridine-3-pyrophosphate (P-->5)-adenosine-3-phosphate (pdUppA-3'-p). The 3',5'-pyrophosphate group of this compound increases its affinity and introduces structural features which seem to be unique in pyrophosphate-containing ligands bound to RNase A, such as the adoption of a syn conformation by the adenosine base at RNase subsite B(2) and the placement of the 5'-beta-phosphate of the adenylate (instead of the alpha-phosphate) at subsite P(1) where the phosphodiester bond cleavage occurs. In this work, we study by multi-ns molecular dynamics simulations the structural properties of RNase A complexes with the ligand pdUppA-3'-p and the related weaker inhibitor dUppA, which lacks the 3' and 5' terminal phosphate groups of pdUppA-3'-p. The simulations show that the adenylate 5'-beta-phosphate binding position and the adenosine syn orientation constitute robust structural features in both complexes, stabilized by persistent interactions with specific active-site residues of subsites P(1) and B(2). The simulation structures are used in conjunction with a continuum-electrostatics (Poisson-Boltzmann) model, to evaluate the relative binding affinity of the two complexes. The computed relative affinity of pdUppA-3'-p varies between -7.9 kcal/mol and -2.8 kcal/mol for a range of protein/ligand dielectric constants (epsilon(p)) 2-20, in good agreement with the experimental value (-3.6 kcal/mol); the agreement becomes exact with epsilon(p) = 8. The success of the continuum-electrostatics model suggests that the differences in affinity of the two ligands originate mainly from electrostatic interactions. A residue decomposition of the electrostatic free energies shows that the terminal phosphate groups of pdUppA-3'-p make increased interactions with residues Lys(7) and Lys(66) of the more remote sites P(2) and P(0), and His(119) of site P(1).
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Leonidas DD, Maiti TK, Samanta A, Dasgupta S, Pathak T, Zographos SE, Oikonomakos NG. The binding of 3′-N-piperidine-4-carboxyl-3′-deoxy-ara-uridine to ribonuclease A in the crystal. Bioorg Med Chem 2006; 14:6055-64. [PMID: 16730994 DOI: 10.1016/j.bmc.2006.05.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 04/28/2006] [Accepted: 05/03/2006] [Indexed: 10/24/2022]
Abstract
The binding of a moderate inhibitor, 3'-N-piperidine-4-carboxyl-3'-deoxy-ara-uridine, to ribonuclease A has been studied by X-ray crystallography at 1.7A resolution. Two inhibitor molecules are bound in the central RNA binding cavity of RNase A exploiting interactions with residues from peripheral binding sites rather than from the active site of the enzyme. The uracyl moiety of the first inhibitor molecule occupies the purine-preferring site of RNase A, while the rest of the molecule projects to the solvent. The second inhibitor molecule binds with the carboxyl group at the pyrimidine recognition site and the uridine moiety exploits interactions with RNase A residues Lys66, His119 and Asp121. Comparative structural analysis of the 3'-N-piperidine-4-carboxyl-3'-deoxy-ara-uridine complex with other RNase A-ligand complexes provides a structural explanation of its potency. The crystal structure of the RNase A-3'-N-piperidine-4-carboxyl-3'-deoxy-ara-uridine complex provides evidence of a novel ligand-binding pattern in RNase A for 3'-N-aminonucleosides that was not anticipated by modelling studies, while it also suggests ways to improve the efficiency and selectivity of such compounds to develop pharmaceuticals against pathologies associated with RNase A homologues.
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Affiliation(s)
- Demetres D Leonidas
- Institute of Organic and Pharmaceutical Chemistry, The National Hellenic Research Foundation, 48 Vas. Constantinou Avenue, 11635 Athens, Greece.
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Abstract
The binding of inosine 5' phosphate (IMP) to ribonuclease A has been studied by kinetic and X-ray crystallographic experiments at high (1.5 A) resolution. IMP is a competitive inhibitor of the enzyme with respect to C>p and binds to the catalytic cleft by anchoring three IMP molecules in a novel binding mode. The three IMP molecules are connected to each other by hydrogen bond and van der Waals interactions and collectively occupy the B1R1P1B2P0P(-1) region of the ribonucleolytic active site. One of the IMP molecules binds with its nucleobase in the outskirts of the B2 subsite and interacts with Glu111 while its phosphoryl group binds in P1. Another IMP molecule binds by following the retro-binding mode previously observed only for guanosines with its nucleobase at B1 and the phosphoryl group in P(-1). The third IMP molecule binds in a novel mode towards the C-terminus. The RNase A-IMP complex provides structural evidence for the functional components of subsite P(-1) while it further supports the role inferred by other studies to Asn71 as the primary structural determinant for the adenine specificity of the B2 subsite. Comparative structural analysis of the IMP and AMP complexes highlights key aspects of the specificity of the base binding subsites of RNase A and provides a structural explanation for their potencies. The binding of IMP suggests ways to develop more potent inhibitors of the pancreatic RNase superfamily using this nucleotide as the starting point.
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Affiliation(s)
- George N Hatzopoulos
- Institute of Organic & Pharmaceutical Chemistry, The National Hellenic Research Foundation, Athens, Greece
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Leonidas DD, Chavali GB, Oikonomakos NG, Chrysina ED, Kosmopoulou MN, Vlassi M, Frankling C, Acharya KR. High-resolution crystal structures of ribonuclease A complexed with adenylic and uridylic nucleotide inhibitors. Implications for structure-based design of ribonucleolytic inhibitors. Protein Sci 2003; 12:2559-74. [PMID: 14573867 PMCID: PMC2366950 DOI: 10.1110/ps.03196603] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The crystal structures of bovine pancreatic ribonuclease A (RNase A) in complex with 3',5'-ADP, 2',5'-ADP, 5'-ADP, U-2'-p and U-3'-p have been determined at high resolution. The structures reveal that each inhibitor binds differently in the RNase A active site by anchoring a phosphate group in subsite P1. The most potent inhibitor of all five, 5'-ADP (Ki = 1.2 microM), adopts a syn conformation (in contrast to 3',5'-ADP and 2',5'-ADP, which adopt an anti), and it is the beta- rather than the alpha-phosphate group that binds to P1. 3',5'-ADP binds with the 5'-phosphate group in P1 and the adenosine in the B2 pocket. Two different binding modes are observed in the two RNase A molecules of the asymmetric unit for 2',5'-ADP. This inhibitor binds with either the 3' or the 5' phosphate groups in subsite P1, and in each case, the adenosine binds in two different positions within the B2 subsite. The two uridilyl inhibitors bind similarly with the uridine moiety in the B1 subsite but the placement of a different phosphate group in P1 (2' versus 3') has significant implications on their potency against RNase A. Comparative structural analysis of the RNase A, eosinophil-derived neurotoxin (EDN), eosinophil cationic protein (ECP), and human angiogenin (Ang) complexes with these and other phosphonucleotide inhibitors provides a wealth of information for structure-based design of inhibitors specific for each RNase. These inhibitors could be developed to therapeutic agents that could control the biological activities of EDN, ECP, and ANG, which play key roles in human pathologies.
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Affiliation(s)
- Demetres D Leonidas
- Institute of Organic and Pharmaceutical Chemistry, The National Hellenic Research Foundation, 11635 Athens, Greece.
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Sica F, Di Fiore A, Zagari A, Mazzarella L. The unswapped chain of bovine seminal ribonuclease: Crystal structure of the free and liganded monomeric derivative. Proteins 2003; 52:263-71. [PMID: 12833549 DOI: 10.1002/prot.10407] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Bovine seminal ribonuclease, a homodimeric enzyme joined covalently by two interchain disulphide bonds, is an equilibrium mixture of two conformational isomers, MxM and M=M. The major form, MxM, whose crystal structure has been previously determined at 1.9 A resolution, presents the swapping of the N-terminal segments (residues 1-15) and composite active sites formed by residues of different chains. The three-dimensional domain swapping does not occur in the M=M form. The different fold of each N-terminal tail is directed by the hinge loop (residue 16-22) connecting the swapping domain to the body of the protein. Reduction and alkylation of interchain disulphide bridges produce a monomeric derivative and a noncovalent swapped dimer, which are both active. The free and nucleotide-bound forms of the monomer have been crystallized at an alkaline pH and refined at 1.45 and 1.65 A resolution, respectively. In both cases, the N-terminal fragment is folded on the main body of the protein to produce an intact active site and a chain architecture very similar to that of bovine pancreatic ribonuclease. In this new fold of the seminal chain, the hinge loop is disordered. Despite the difference between the tertiary structure of the monomer and that of the chains in the MxM form, the active sites of the two enzymes are virtually indistinguishable. Furthermore, the structure of the liganded enzyme represents the first example of a ribonuclease complex studied at an alkaline pH and provides new information on the binding of a nucleotide when the catalytic histidines are deprotonated.
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Affiliation(s)
- Filomena Sica
- Dipartimento di Chimica, Università degli Studi di Napoli Federico II, Napoli, Italy
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Abstract
The most potent low molecular weight inhibitors of pancreatic RNase superfamily enzymes reported to date are synthetic derivatives of adenosine 5(')-pyrophosphate. Here we have investigated the effects of six natural nucleotides that also incorporate this moiety (NADP(+), NADPH, ATP, Ap(3)A, Ap(4)A, and Ap(5)A) on the activities of RNase A and two of its homologues, eosinophil-derived neurotoxin and angiogenin. With eosinophil-derived neurotoxin and angiogenin, Ap(5)A is comparable to the tightest binding inhibitors identified previously (K(i) values at pH 5.9 are 370 nM and 100 microM, respectively); it ranks among the strongest small antagonists of RNase A as well (K(i)=230 nM). The K(i) for NADPH with angiogenin is similar to that of Ap(5)A. These findings suggest that Ap(5)A and NADPH may serve as useful new leads for inhibitor design. Examination of inhibition under physiological conditions indicates that NADPH, ATP, and Ap(5)A may suppress intracellular RNase activity significantly in vivo.
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Affiliation(s)
- Kapil Kumar
- Center for Biochemical and Biophysical Sciences and Medicine, Harvard Medical School, One Kendall Square, Building 600, Third Floor, Cambridge, MA 02139, USA
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Kao RYT, Jenkins JL, Olson KA, Key ME, Fett JW, Shapiro R. A small-molecule inhibitor of the ribonucleolytic activity of human angiogenin that possesses antitumor activity. Proc Natl Acad Sci U S A 2002; 99:10066-71. [PMID: 12118120 PMCID: PMC126625 DOI: 10.1073/pnas.152342999] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The results of previous preclinical and clinical studies have identified angiogenin (ANG) as a potentially important target for anticancer therapy. Here we report the design and implementation of a high-throughput screening assay to identify small molecules that bind to the ribonucleolytic active site of ANG, which is critically involved in the induction of angiogenesis by this protein. Screening of 18,310 compounds from the National Cancer Institute (NCI) Diversity Set and ChemBridge DIVERSet yielded 15 hits that inhibit the enzymatic activity of ANG with K(i) values <100 microM. One of these, NCI compound 65828 [8-amino-5-(4'-hydroxybiphenyl-4-ylazo)naphthalene-2-sulfonate; K(i) = 81 microM], was selected for more detailed studies. Minor changes in ANG or ligand structure markedly reduced potency, demonstrating that inhibition reflects active-site rather than nonspecific binding; these observations are consistent with a computationally generated model of the ANG.65828 complex. Local treatment with modest doses of 65828 significantly delayed the formation of s.c. tumors from two distinct human cancer cell types in athymic mice. ANG is the likely target involved because (i) a 65828 analogue with much lower potency against the enzymatic activity of ANG failed to exert any antitumor effect, (ii) tumors from 65828-treated mice had fewer interior blood vessels than those from control mice, and (iii) 65828 appears to have no direct effect on the tumor cells. Our findings provide considerable support for the targeting of the enzymatic active site of ANG as a strategy for developing new anticancer drugs.
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Affiliation(s)
- Richard Y T Kao
- Center for Biochemical and Biophysical Sciences, Harvard Medical School, Cambridge, MA 02139, USA
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