1
|
Mosseri A, Sancho-Albero M, Mercurio FA, Leone M, De Cola L, Romanelli A. Tryptophan-PNA gc Conjugates Self-Assemble to Form Fibers. Bioconjug Chem 2023; 34:1429-1438. [PMID: 37486977 PMCID: PMC10436247 DOI: 10.1021/acs.bioconjchem.3c00200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/07/2023] [Indexed: 07/26/2023]
Abstract
Peptide nucleic acids and their conjugates to peptides can self-assemble and generate complex architectures. In this work, we explored the self-assembly of PNA dimers conjugated to the dipeptide WW. Our studies suggest that the indole ring of tryptophan promotes aggregation of the conjugates. The onset of fluorescence is observed upon self-assembly. The structure of self-assembled WWgc is concentration-dependent, being spherical at low concentrations and fibrous at high concentrations. As suggested by molecular modeling studies, fibers are stabilized by stacking interactions between tryptophans and Watson-Crick hydrogen bonds between nucleobases.
Collapse
Affiliation(s)
- Andrea Mosseri
- Dipartimento
di Scienze Farmaceutiche, Università
Degli Studi di Milano, via Venezian 21, 20133 Milano, Italy
| | - María Sancho-Albero
- Department
of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Flavia Anna Mercurio
- Istituto
di Biostrutture e Bioimmagini—CNR, via Pietro Castellino 111, 80131 Naples, Italy
| | - Marilisa Leone
- Istituto
di Biostrutture e Bioimmagini—CNR, via Pietro Castellino 111, 80131 Naples, Italy
| | - Luisa De Cola
- Dipartimento
di Scienze Farmaceutiche, Università
Degli Studi di Milano, via Venezian 21, 20133 Milano, Italy
- Department
of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 20156 Milano, Italy
| | - Alessandra Romanelli
- Dipartimento
di Scienze Farmaceutiche, Università
Degli Studi di Milano, via Venezian 21, 20133 Milano, Italy
| |
Collapse
|
2
|
Tamez A, Nilsson L, Mihailescu MR, Evanseck JD. Parameterization of the miniPEG-Modified γPNA Backbone: Toward Induced γPNA Duplex Dissociation. J Chem Theory Comput 2023. [PMID: 37195939 DOI: 10.1021/acs.jctc.2c01163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
γ-Modified peptide nucleic acids (γPNAs) serve as potential therapeutic agents against genetic diseases. Miniature poly(ethylene glycol) (miniPEG) has been reported to increase solubility and binding affinity toward genetic targets, yet details of γPNA structure and dynamics are not understood. Within our work, we parameterized missing torsional and electrostatic terms for the miniPEG substituent on the γ-carbon atom of the γPNA backbone in the CHARMM force field. Microsecond timescale molecular dynamics simulations were carried out on six miniPEG-modified γPNA duplexes from NMR structures (PDB ID: 2KVJ). Three NMR models for the γPNA duplex (PDB ID: 2KVJ) were simulated as a reference for structural and dynamic changes captured for the miniPEG-modified γPNA duplex. Principal component analysis performed on the γPNA backbone atoms identified a single isotropic conformational substate (CS) for the NMR simulations, whereas four anisotropic CSs were identified for the ensemble of miniPEG-modified γPNA simulations. The NMR structures were found to have a 23° helical bend toward the major groove, consistent with our simulated CS structure of 19.0°. However, a significant difference between simulated methyl- and miniPEG-modified γPNAs involved the opportunistic invasion of miniPEG through the minor and major groves. Specifically, hydrogen bond fractional analysis showed that the invasion was particularly prone to affect the second G-C base pair, reducing the Watson-Crick base pair hydrogen bond by 60% over the six simulations, whereas the A-T base pairs decreased by only 20%. Ultimately, the invasion led to base stack reshuffling, where the well-ordered base stacking was reduced to segmented nucleobase stacking interactions. Our 6 μs timescale simulations indicate that duplex dissociation suggests the onset toward γPNA single strands, consistent with the experimental observation of decreased aggregation. To complement the insight of miniPEG-modified γPNA structure and dynamics, the new miniPEG force field parameters allow for further exploration of such modified γPNA single strands as potential therapeutic agents against genetic diseases.
Collapse
Affiliation(s)
- Angel Tamez
- Center for Computational Sciences and the Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, United States
| | - Lennart Nilsson
- Department of Biosciences and Nutrition, Karolinska Institute, Solnavägen 1, 171 77 Solna, Sweden
| | - Mihaela-Rita Mihailescu
- Center for Computational Sciences and the Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, United States
| | - Jeffrey D Evanseck
- Center for Computational Sciences and the Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, United States
| |
Collapse
|
3
|
Dhami I, Thadke SA, Ly DH. Development of the Right- and Left-Handed Gamma Peptide Nucleic Acid Building Blocks for On-Resin Chemical Functionalization. J Org Chem 2022; 87:13873-13881. [PMID: 36190146 DOI: 10.1021/acs.joc.2c01560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Gamma peptide nucleic acids (PNAs) are a promising class of nucleic acid mimics that adopt either a right- or left-handed helical motif as individual strands and hybridize to DNA or RNA with high affinity and sequence specificity, or not at all, depending on the helical sense. They are attractive as antisense and antigene reagents, as well as building blocks for molecular self-assembly; however, they have not been widely adopted due to their relatively poor biophysical attributes and the challenge in chemical modifications. Here, we report the development of a set of universal monomers, four each for both the right- and left-handed conformers, that permit rapid and selective on-resin chemical functionalization and diversification. The system is modular, permitting incorporation of different chemical groups in the backbone without causing adverse effects on hybridization. The approach overcomes the need to prepare a new set of monomers each time a different chemical group is introduced in the backbone. The newly added synthetic flexibility, along with superior hybridization property, recognition orthogonality, and helical sense translational capability, significantly expands the scope of gamma PNA in biology, biotechnology, and molecular engineering.
Collapse
Affiliation(s)
- Isha Dhami
- Department of Chemistry and Institute for Bimolecular Design and Discovery (IBD), Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Shivaji A Thadke
- Department of Chemistry and Institute for Bimolecular Design and Discovery (IBD), Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Danith H Ly
- Department of Chemistry and Institute for Bimolecular Design and Discovery (IBD), Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| |
Collapse
|
4
|
Suparpprom C, Vilaivan T. Perspectives on conformationally constrained peptide nucleic acid (PNA): insights into the structural design, properties and applications. RSC Chem Biol 2022; 3:648-697. [PMID: 35755191 PMCID: PMC9175113 DOI: 10.1039/d2cb00017b] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/17/2022] [Indexed: 11/21/2022] Open
Abstract
Peptide nucleic acid or PNA is a synthetic DNA mimic that contains a sequence of nucleobases attached to a peptide-like backbone derived from N-2-aminoethylglycine. The semi-rigid PNA backbone acts as a scaffold that arranges the nucleobases in a proper orientation and spacing so that they can pair with their complementary bases on another DNA, RNA, or even PNA strand perfectly well through the standard Watson-Crick base-pairing. The electrostatically neutral backbone of PNA contributes to its many unique properties that make PNA an outstanding member of the xeno-nucleic acid family. Not only PNA can recognize its complementary nucleic acid strand with high affinity, but it does so with excellent specificity that surpasses the specificity of natural nucleic acids and their analogs. Nevertheless, there is still room for further improvements of the original PNA in terms of stability and specificity of base-pairing, direction of binding, and selectivity for different types of nucleic acids, among others. This review focuses on attempts towards the rational design of new generation PNAs with superior performance by introducing conformational constraints such as a ring or a chiral substituent in the PNA backbone. A large collection of conformationally rigid PNAs developed during the past three decades are analyzed and compared in terms of molecular design and properties in relation to structural data if available. Applications of selected modified PNA in various areas such as targeting of structured nucleic acid targets, supramolecular scaffold, biosensing and bioimaging, and gene regulation will be highlighted to demonstrate how the conformation constraint can improve the performance of the PNA. Challenges and future of the research in the area of constrained PNA will also be discussed.
Collapse
Affiliation(s)
- Chaturong Suparpprom
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Naresuan University, Tah-Poe District, Muang Phitsanulok 65000 Thailand
- Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University Phayathai Road Pathumwan Bangkok 10330 Thailand
| | - Tirayut Vilaivan
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Naresuan University, Tah-Poe District, Muang Phitsanulok 65000 Thailand
- Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University Phayathai Road Pathumwan Bangkok 10330 Thailand
| |
Collapse
|
5
|
Brodyagin N, Katkevics M, Kotikam V, Ryan CA, Rozners E. Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications. Beilstein J Org Chem 2021; 17:1641-1688. [PMID: 34367346 PMCID: PMC8313981 DOI: 10.3762/bjoc.17.116] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/28/2021] [Indexed: 12/23/2022] Open
Abstract
Peptide nucleic acid (PNA) is arguably one of the most successful DNA mimics, despite a most dramatic departure from the native structure of DNA. The present review summarizes 30 years of research on PNA's chemistry, optimization of structure and function, applications as probes and diagnostics, and attempts to develop new PNA therapeutics. The discussion starts with a brief review of PNA's binding modes and structural features, followed by the most impactful chemical modifications, PNA enabled assays and diagnostics, and discussion of the current state of development of PNA therapeutics. While many modifications have improved on PNA's binding affinity and specificity, solubility and other biophysical properties, the original PNA is still most frequently used in diagnostic and other in vitro applications. Development of therapeutics and other in vivo applications of PNA has notably lagged behind and is still limited by insufficient bioavailability and difficulties with tissue specific delivery. Relatively high doses are required to overcome poor cellular uptake and endosomal entrapment, which increases the risk of toxicity. These limitations remain unsolved problems waiting for innovative chemistry and biology to unlock the full potential of PNA in biomedical applications.
Collapse
Affiliation(s)
- Nikita Brodyagin
- Department of Chemistry, Binghamton University, The State University of New York, Binghamton, New York 13902, United States
| | - Martins Katkevics
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - Venubabu Kotikam
- Department of Chemistry, Binghamton University, The State University of New York, Binghamton, New York 13902, United States
| | - Christopher A Ryan
- Department of Chemistry, Binghamton University, The State University of New York, Binghamton, New York 13902, United States
| | - Eriks Rozners
- Department of Chemistry, Binghamton University, The State University of New York, Binghamton, New York 13902, United States
| |
Collapse
|
6
|
Meena CL, Singh D, Kizhakeetil B, Prasad M, George M, Tothadi S, Sanjayan GJ. Triazine-Based Janus G-C Nucleobase as a Building Block for Self-Assembly, Peptide Nucleic Acids, and Smart Polymers. J Org Chem 2021; 86:3186-3195. [PMID: 33523657 DOI: 10.1021/acs.joc.0c02530] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This communication reports on the utility of a triazine-based self-assembling system, reminiscent of a Janus G-C nucleobase, as a building block for developing (1) supramolecular polymers, (2) peptide nucleic acids (PNAs), and (3) smart polymers. The strategically positioned self-complementary triple H-bonding arrays DDA and AAD facilitate efficient self-assembly, leading to a linear supramolecular polymer.
Collapse
Affiliation(s)
- Chhuttan L Meena
- Organic Chemistry Division, Council of Scientific and Industrial Research National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
| | - Dharmendra Singh
- Organic Chemistry Division, Council of Scientific and Industrial Research National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
| | - Bhavya Kizhakeetil
- Organic Chemistry Division, Council of Scientific and Industrial Research National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
| | - Manasa Prasad
- Organic Chemistry Division, Council of Scientific and Industrial Research National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
| | - Malini George
- Organic Chemistry Division, Council of Scientific and Industrial Research National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
| | - Srinu Tothadi
- Organic Chemistry Division, Council of Scientific and Industrial Research National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
| | - Gangadhar J Sanjayan
- Organic Chemistry Division, Council of Scientific and Industrial Research National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune 411008, India
| |
Collapse
|
7
|
Moccia M, Mercurio FA, Langella E, Piacenti V, Leone M, Adamo MFA, Saviano M. Structural Insights on Tiny Peptide Nucleic Acid (PNA) Analogues of miRNA-34a: An in silico and Experimental Integrated Approach. Front Chem 2020; 8:568575. [PMID: 33330358 PMCID: PMC7719796 DOI: 10.3389/fchem.2020.568575] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 11/02/2020] [Indexed: 11/17/2022] Open
Abstract
In the present work, structural features of the interaction between peptide nucleic acid (PNA)-based analogs of the tumor-suppressor microRNA-34a with both its binding sites on MYCN mRNA were investigated. In particular, the region from base 1 to 8 ("seed" region) of miR-34a was reproduced in the form of an 8-mer PNA fragment (tiny PNA), and binding to target 3'UTR MYCN mRNA, was studied by a seldom reported and detailed NMR characterization, providing evidence for the formation of anti-parallel duplexes with a well-organized structural core. The formation of PNA-3'UTR duplexes was also confirmed by Circular Dichroism, and their melting curves were measured by UV spectroscopy. Nevertheless, this study offered a valuable comparison between molecular dynamics predictions and experimental evidence, which showed great correlation. Preliminary uptake assays were carried out in Neuroblastoma Kelly cells, using short peptide conjugates as carriers and FITC fluorescent tag for subcellular localization. Moderate internalization was observed without the use of transfecting agents. The reported results corroborate the interest toward the design and development of chimeric PNA/RNA sequences as effective RNA-targeting agents.
Collapse
Affiliation(s)
- Maria Moccia
- Institute of Crystallography, National Research Council, Department of Chemical Sciences and Materials Technologies, Bari, Italy
| | - Flavia Anna Mercurio
- Institute of Biostructures and Bioimaging, National Research Council, Naples, Italy
| | - Emma Langella
- Institute of Biostructures and Bioimaging, National Research Council, Naples, Italy
| | - Valerio Piacenti
- Royal College of Surgeons in Ireland, Department of Pharmaceutical and Medicinal Chemistry, Dublin, Ireland
| | - Marilisa Leone
- Institute of Biostructures and Bioimaging, National Research Council, Naples, Italy
| | - Mauro F. A. Adamo
- Royal College of Surgeons in Ireland, Department of Pharmaceutical and Medicinal Chemistry, Dublin, Ireland
| | - Michele Saviano
- Institute of Crystallography, National Research Council, Department of Chemical Sciences and Materials Technologies, Bari, Italy
| |
Collapse
|
8
|
Gamble Jarvi A, Sargun A, Bogetti X, Wang J, Achim C, Saxena S. Development of Cu 2+-Based Distance Methods and Force Field Parameters for the Determination of PNA Conformations and Dynamics by EPR and MD Simulations. J Phys Chem B 2020; 124:7544-7556. [PMID: 32790374 DOI: 10.1021/acs.jpcb.0c05509] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Peptide nucleic acids (PNAs) are a promising group of synthetic analogues of DNA and RNA that offer several distinct advantages over the naturally occurring nucleic acids for applications in biosensing, drug delivery, and nanoelectronics. Because of its structural differences from DNA/RNA, methods to analyze and assess the structure, conformations, and dynamics are needed. In this work, we develop synergistic techniques for the study of the PNA conformation. We use CuQ2, a Cu2+ complex with 8-hydroxyquinoline (HQ), as an alternative base pair and as a spin label in electron paramagnetic resonance (EPR) distance methods. We use molecular dynamics (MD) simulations with newly developed force field parameters for the spin labels to interpret the distance constraints determined by EPR. We complement these methods by UV-vis and circular dichroism measurements and assess the efficacy of the Cu2+ label on a PNA duplex whose backbone is based on aminoethylglycine and a duplex with a hydroxymethyl backbone modification. We show that the Cu2+ label functions efficiently within the standard PNA and the hydroxymethyl-modified PNA and that the MD parameters may be used to accurately reproduce our EPR findings. Through the combination of EPR and MD, we gain new insights into the PNA structure and conformations as well as into the mechanism of orientational selectivity in Cu2+ EPR at X-band. These results present for the first time a rigid Cu2+ spin label used for EPR distance measurements in PNA and the accompanying MD force fields for the spin label. Our studies also reveal that the spin labels have a low impact on the structure of the PNA duplexes. The combined MD and EPR approach represents an important new tool for the characterization of the PNA duplex structure and provides valuable information to aid in the rational application of PNA at large.
Collapse
Affiliation(s)
- Austin Gamble Jarvi
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Artur Sargun
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Xiaowei Bogetti
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Junmei Wang
- Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15206, United States
| | - Catalina Achim
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Sunil Saxena
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| |
Collapse
|
9
|
Antibacterial Peptide Nucleic Acids-Facts and Perspectives. Molecules 2020; 25:molecules25030559. [PMID: 32012929 PMCID: PMC7038079 DOI: 10.3390/molecules25030559] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 12/13/2022] Open
Abstract
Antibiotic resistance is an escalating, worldwide problem. Due to excessive use of antibiotics, multidrug-resistant bacteria have become a serious threat and a major global healthcare problem of the 21st century. This fact creates an urgent need for new and effective antimicrobials. The common strategies for antibiotic discovery are based on either modifying existing antibiotics or screening compound libraries, but these strategies have not been successful in recent decades. An alternative approach could be to use gene-specific oligonucleotides, such as peptide nucleic acid (PNA) oligomers, that can specifically target any single pathogen. This approach broadens the range of potential targets to any gene with a known sequence in any bacterium, and could significantly reduce the time required to discover new antimicrobials or their redesign, if resistance arises. We review the potential of PNA as an antibacterial molecule. First, we describe the physicochemical properties of PNA and modifications of the PNA backbone and nucleobases. Second, we review the carriers used to transport PNA to bacterial cells. Furthermore, we discuss the PNA targets in antibacterial studies focusing on antisense PNA targeting bacterial mRNA and rRNA.
Collapse
|
10
|
Jasiński M, Feig M, Trylska J. Improved Force Fields for Peptide Nucleic Acids with Optimized Backbone Torsion Parameters. J Chem Theory Comput 2018; 14:3603-3620. [PMID: 29791152 DOI: 10.1021/acs.jctc.8b00291] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Peptide nucleic acids are promising nucleic acid analogs for antisense therapies as they can form stable duplex and triplex structures with DNA and RNA. Computational studies of PNA-containing duplexes and triplexes are an important component for guiding their design, yet existing force fields have not been well validated and parametrized with modern computational capabilities. We present updated CHARMM and Amber force fields for PNA that greatly improve the stability of simulated PNA-containing duplexes and triplexes in comparison with experimental structures and allow such systems to be studied on microsecond time scales. The force field modifications focus on reparametrized PNA backbone torsion angles to match high-level quantum mechanics reference energies for a model compound. The microsecond simulations of PNA-PNA, PNA-DNA, PNA-RNA, and PNA-DNA-PNA complexes also allowed a comprehensive analysis of hydration and ion interactions with such systems.
Collapse
Affiliation(s)
- Maciej Jasiński
- Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan 48824 , United States.,Centre of New Technologies , University of Warsaw , Warsaw , Poland
| | - Michael Feig
- Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Joanna Trylska
- Centre of New Technologies , University of Warsaw , Warsaw , Poland
| |
Collapse
|
11
|
Abstract
An impressive array of antigene approaches has been developed for recognition of double helical DNA over the past three decades; however, few have exploited the 'Watson-Crick' base-pairing rules for establishing sequence-specific recognition. One approach employs peptide nucleic acid as a molecular reagent and strand invasion as a binding mode. However, even with integration of the latest conformationally-preorganized backbone design, such an approach is generally confined to sub-physiological conditions due to the lack of binding energy. Here we report the use of a class of shape-selective, bifacial nucleic acid recognition elements, namely Janus bases, for targeting double helical DNA or RNA. Binding occurs in a highly sequence-specific manner under physiologically relevant conditions. The work may provide a foundation for the design of oligonucleotides for targeting the secondary and tertiary structures of nucleic acid biopolymers.
Collapse
|
12
|
Beall E, Ulku S, Liu C, Wierzbinski E, Zhang Y, Bae Y, Zhang P, Achim C, Beratan DN, Waldeck DH. Effects of the Backbone and Chemical Linker on the Molecular Conductance of Nucleic Acid Duplexes. J Am Chem Soc 2017; 139:6726-6735. [PMID: 28434220 DOI: 10.1021/jacs.7b02260] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Scanning tunneling microscope break junction measurements are used to examine how the molecular conductance of nucleic acids depends on the composition of their backbone and the linker group to the electrodes. Molecular conductances of 10 base pair long homoduplexes of DNA, aeg-PNA, γ-PNA, and a heteroduplex of DNA/aeg-PNA with identical nucleobase sequence were measured. The molecular conductance was found to vary by 12 to 13 times with the change in backbone. Computational studies show that the molecular conductance differences between nucleic acids of different backbones correlate with differences in backbone structural flexibility. The molecular conductance was also measured for duplexes connected to the electrode through two different linkers, one directly to the backbone and one directly to the nucleobase stack. While the linker causes an order-of-magnitude increase in the overall conductance for a particular duplex, the differences in the electrical conductance with backbone composition are preserved. The highest molecular conductance value, 0.06G0, was measured for aeg-PNA duplexes with a base stack linker. These findings reveal an important new strategy for creating longer and more complex electroactive, nucleic acid assemblies.
Collapse
Affiliation(s)
- Edward Beall
- Chemistry Department, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Selma Ulku
- Chemistry Department, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Chaoren Liu
- Chemistry Department, Duke University , Durham, North Carolina 27708, United States
| | - Emil Wierzbinski
- Chemistry Department, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| | - Yuqi Zhang
- Chemistry Department, Duke University , Durham, North Carolina 27708, United States
| | - Yookyung Bae
- Chemistry Department, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Peng Zhang
- Chemistry Department, Duke University , Durham, North Carolina 27708, United States
| | - Catalina Achim
- Chemistry Department, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - David N Beratan
- Chemistry Department, Duke University , Durham, North Carolina 27708, United States
| | - David H Waldeck
- Chemistry Department, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States
| |
Collapse
|
13
|
Verona MD, Verdolino V, Palazzesi F, Corradini R. Focus on PNA Flexibility and RNA Binding using Molecular Dynamics and Metadynamics. Sci Rep 2017; 7:42799. [PMID: 28211525 PMCID: PMC5314342 DOI: 10.1038/srep42799] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/13/2017] [Indexed: 12/20/2022] Open
Abstract
Peptide Nucleic Acids (PNAs) can efficiently target DNA or RNA acting as chemical tools for gene regulation. Their backbone modification and functionalization is often used to increase the affinity for a particular sequence improving selectivity. The understanding of the trading forces that lead the single strand PNA to bind the DNA or RNA sequence is preparatory for any further rational design, but a clear and unique description of this process is still not complete. In this paper we report further insights into this subject, by a computational investigation aiming at the characterization of the conformations of a single strand PNA and how these can be correlated to its capability in binding DNA/RNA. Employing Metadynamics we were able to better define conformational pre-organizations of the single strand PNA and γ-modified PNA otherwise unrevealed through classical molecular dynamics. Our simulations driven on backbone modified PNAs lead to the conclusion that this γ-functionalization affects the single strand preorganization and targeting properties to the DNA/RNA, in agreement with circular dichroism (CD) spectra obtained for this class of compounds. MD simulations on PNA:RNA dissociation and association mechanisms allowed to reveal the critical role of central bases and preorganization in the binding process.
Collapse
Affiliation(s)
| | - Vincenzo Verdolino
- Department of Chemistry and Applied Biosciences, ETH Zurich, c/o Università della Svizzera Italiana Campus, 6900 Lugano, Switzerland
- Facoltà di Informatica, Instituto di Scienze Computazionali, Università della Svizzera Italiana, 6900 Lugano, Switzerland
| | - Ferruccio Palazzesi
- Department of Chemistry and Applied Biosciences, ETH Zurich, c/o Università della Svizzera Italiana Campus, 6900 Lugano, Switzerland
- Facoltà di Informatica, Instituto di Scienze Computazionali, Università della Svizzera Italiana, 6900 Lugano, Switzerland
| | - Roberto Corradini
- Dipartimento di Chimica, University of Parma, Italy, 43124, Italy
- National Institute for Biostructures and Biosystems (INBB)-Viale delle Medaglie d’Oro, 305, 00136 Roma, Italy
| |
Collapse
|
14
|
Viéville JMP, Barluenga S, Winssinger N, Delsuc MA. Duplex formation and secondary structure of γ-PNA observed by NMR and CD. Biophys Chem 2015; 210:9-13. [PMID: 26493008 DOI: 10.1016/j.bpc.2015.09.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 08/13/2015] [Accepted: 09/07/2015] [Indexed: 10/23/2022]
Abstract
Peptide nucleic acids (PNAs) are non-natural oligonucleotides mimics, wherein the phosphoribose backbone has been replaced by a peptidic moiety (N-(2-aminoethyl)glycine). This peptidic backbone lends itself to substitution and the γ-position has proven to yield oligomers with enhanced hybridization properties. In this study, we use Nuclear Magnetic Resonance (NMR) and Circular Dichroism (CD) to explore the properties of the supramolecular duplexes formed by these species. We show that standard Watson-Crick base pair as well as non-standard ones are formed in solution. The duplexes thus formed present marked melting transition temperatures substantially higher than their nucleic acid homologs. Moreover, the presence of a chiral group on the γ-peptidic backbone increases further this transition temperature, leading to very stable duplexes. PNA duplexes with a chiral backbone present a marked chiral secondary structure, observed by CD, and showing a common folding pattern for all studied structures. Nevertheless small differences are observed depending on the details of the nucleobase sequence.
Collapse
Affiliation(s)
- J M P Viéville
- Strasbourg University, Plateforme d'Analyse Chimique de Strasbourg Illkirch, 74 route du Rhin 67401 Illkirch, France
| | - S Barluenga
- Department of Organic Chemistry, University of Geneva, Geneva CH1211, Switzerland
| | - N Winssinger
- Department of Organic Chemistry, University of Geneva, Geneva CH1211, Switzerland
| | - M A Delsuc
- IGBMC, CNRS UMR 7104, 1 rue Laurent Fries BP10142, 67404 Illkirch France.
| |
Collapse
|
15
|
Dix AV, Moss SM, Phan K, Hoppe T, Paoletta S, Kozma E, Gao ZG, Durell SR, Jacobson KA, Appella DH. Programmable nanoscaffolds that control ligand display to a G-protein-coupled receptor in membranes to allow dissection of multivalent effects. J Am Chem Soc 2014; 136:12296-303. [PMID: 25116377 PMCID: PMC4156868 DOI: 10.1021/ja504288s] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
A programmable
ligand display system can be used to dissect the
multivalent effects of ligand binding to a membrane receptor. An antagonist
of the A2A adenosine receptor, a G-protein-coupled receptor
that is a drug target for neurodegenerative conditions, was displayed
in 35 different multivalent configurations, and binding to A2A was determined. A theoretical model based on statistical mechanics
was developed to interpret the binding data, suggesting the importance
of receptor dimers. Using this model, extended multivalent arrangements
of ligands were constructed with progressive improvements in binding
to A2A. The results highlight the ability to use a highly
controllable multivalent approach to determine optimal ligand valency
and spacing that can be subsequently optimized for binding to a membrane
receptor. Models explaining the multivalent binding data are also
presented.
Collapse
Affiliation(s)
- Andrew V Dix
- Laboratory of Bioorganic Chemistry, NIDDK, ‡Laboratory of Biochemistry and Genetics, NIDDK, and §Laboratory of Cell Biology, CCR, NCI, National Institutes of Health , Bethesda, Maryland 20892, United States
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Wierzbinski E, de Leon A, Yin X, Balaeff A, Davis KL, Reppireddy S, Venkatramani R, Keinan S, Ly DH, Madrid M, Beratan DN, Achim C, Waldeck DH. Effect of Backbone Flexibility on Charge Transfer Rates in Peptide Nucleic Acid Duplexes. J Am Chem Soc 2012; 134:9335-42. [DOI: 10.1021/ja301677z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emil Wierzbinski
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
15260, United States
| | - Arnie de Leon
- Department
of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania
15213, United States
| | - Xing Yin
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
15260, United States
| | - Alexander Balaeff
- Department
of Chemistry, Duke University, Durham,
North Carolina 27708, United
States
| | - Kathryn L. Davis
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
15260, United States
| | - Srinivas Reppireddy
- Department
of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania
15213, United States
| | - Ravindra Venkatramani
- Department
of Chemistry, Duke University, Durham,
North Carolina 27708, United
States
| | - Shahar Keinan
- Department
of Chemistry, Duke University, Durham,
North Carolina 27708, United
States
| | - Danith H. Ly
- Department
of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania
15213, United States
| | - Marcela Madrid
- Pittsburgh Supercomputing Center, Pittsburgh, Pennsylvania 15213, United States
| | - David N. Beratan
- Departments of Chemistry, Biochemistry,
and Physics, Duke University, Durham, North
Carolina 27708, United States
| | - Catalina Achim
- Department
of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania
15213, United States
| | - David H. Waldeck
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
15260, United States
| |
Collapse
|
17
|
Loakes D. Nucleotides and nucleic acids; oligo- and polynucleotides. ORGANOPHOSPHORUS CHEMISTRY 2012. [DOI: 10.1039/9781849734875-00169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- David Loakes
- Medical Research Council Laboratory of Molecular Biology, Hills Road Cambridge CB2 2QH UK
| |
Collapse
|
18
|
Rapireddy S, Nhon L, Meehan RE, Franks J, Stolz DB, Tran D, Selsted ME, Ly DH. RTD-1mimic containing γPNA scaffold exhibits broad-spectrum antibacterial activities. J Am Chem Soc 2012; 134:4041-4. [PMID: 22332599 PMCID: PMC4848027 DOI: 10.1021/ja211867j] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Macrocyclic peptides with multiple disulfide cross-linkages, such as those produced by plants and those found in nonhuman primates, as components of the innate immunity, hold great promise for molecular therapy because of their broad biological activities and high chemical, thermal, and enzymatic stability. However, for some, because of their intricate spatial arrangement and elaborate interstrand cross-linkages, they are difficult to prepare de novo in large quantities and high purity, due to the nonselective nature of disulfide-bond formation. We show that the disulfide bridges of RTD-1, a member of the θ-defensin subfamily, could be replaced with noncovalent Watson-Crick hydrogen bonds without significantly affecting its biological activities. The work provides a general strategy for engineering conformationally rigid, cyclic peptides without the need for disulfide-bond reinforcement.
Collapse
Affiliation(s)
- Srinivas Rapireddy
- Department of Chemistry and Center for Nucleic Acids Science and Technology (CNAST), Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
| | - Linda Nhon
- Department of Chemistry and Center for Nucleic Acids Science and Technology (CNAST), Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
| | - Robert E. Meehan
- Department of Chemistry and Center for Nucleic Acids Science and Technology (CNAST), Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
| | - Jonathan Franks
- Department of Cell Biology & Physiology, University of Pittsburgh School of Medicine, S362 BST, 3500 Terrace Street, Pittsburgh, PA 15261
| | - Donna Beer Stolz
- Department of Cell Biology & Physiology, University of Pittsburgh School of Medicine, S362 BST, 3500 Terrace Street, Pittsburgh, PA 15261
| | - Dat Tran
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089
| | - Michael E. Selsted
- Department of Pathology & Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089
| | - Danith H. Ly
- Department of Chemistry and Center for Nucleic Acids Science and Technology (CNAST), Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
| |
Collapse
|
19
|
Venkatramani R, Keinan S, Balaeff A, Beratan DN. Nucleic Acid Charge Transfer: Black, White and Gray. Coord Chem Rev 2011; 255:635-648. [PMID: 21528017 PMCID: PMC3081592 DOI: 10.1016/j.ccr.2010.12.010] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Theoretical studies of charge transport in deoxyribonucleic acid (DNA) and peptide nucleic acid (PNA) indicate that structure and dynamics modulate the charge transfer rates, and that different members of a structural ensemble support different charge transport mechanisms. Here, we review the influences of nucleobase geometry, electronic structure, solvent environment, and thermal conformational fluctuations on the charge transfer mechanism. We describe an emerging framework for understanding the diversity of charge transport mechanisms seen in nucleic acids.
Collapse
Affiliation(s)
| | - Shahar Keinan
- Department of Chemistry, Duke University, Durham, North Carolina 27708
| | - Alexander Balaeff
- Department of Chemistry, Duke University, Durham, North Carolina 27708
| | | |
Collapse
|
20
|
Yeh JI, Shivachev B, Rapireddy S, Crawford MJ, Gil RR, Du S, Madrid M, Ly DH. Crystal structure of chiral gammaPNA with complementary DNA strand: insights into the stability and specificity of recognition and conformational preorganization. J Am Chem Soc 2010; 132:10717-27. [PMID: 20681704 DOI: 10.1021/ja907225d] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have determined the structure of a PNA-DNA duplex to 1.7 A resolution by multiple-wavelength anomalous diffraction phasing method on a zinc derivative. This structure represents the first high-resolution 3D view of a hybrid duplex containing a contiguous chiral PNA strand with complete gamma-backbone modification ("gammaPNA"). Unlike the achiral counterpart, which adopts a random-fold, this particular gammaPNA is already preorganized into a right-handed helix as a single strand. The new structure illustrates the unique characteristics of this modified PNA, possessing conformational flexibility while maintaining sufficient structural integrity to ultimately adopt the preferred P-helical conformation upon hybridization with DNA. The unusual structural adaptability found in the gammaPNA strand is crucial for enabling the accommodation of backbone modifications while constraining conformational states. In conjunction with NMR analysis characterizing the structures and substructures of the individual building blocks, these results provide unprecedented insights into how this new class of chiral gammaPNA is preorganized and stabilized, before and after hybridization with a cDNA strand. Such knowledge is crucial for the future design and development of PNA for applications in biology, biotechnology, and medicine.
Collapse
Affiliation(s)
- Joanne I Yeh
- Department of Structural Biology, University of Pittsburgh Medical School 1036 BST3, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15260, USA.
| | | | | | | | | | | | | | | |
Collapse
|