1
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Mirlohi MS, Pishbin E, Dezhkam R, Kiani MJ, Shamloo A, Salami S. Innovative PNA-LB mediated allele-specific LAMP for KRAS mutation profiling on a compact lab-on-a-disc device. Talanta 2024; 276:126224. [PMID: 38772176 DOI: 10.1016/j.talanta.2024.126224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/24/2024] [Accepted: 05/05/2024] [Indexed: 05/23/2024]
Abstract
Tailored healthcare, an approach focused on individual patients, requires integrating emerging interdisciplinary technologies to develop accurate and user-friendly diagnostic tools. KRAS mutations, prevalent in various common cancers, are crucial determinants in selecting patients for novel KRAS inhibitor therapies. This study presents a novel state-of-the-art Lab-on-a-Disc system utilizing peptide nucleic acids-loop backward (PNA-LB) mediated allele-specific loop-mediated isothermal amplification (LAMP) for detecting the frequent G12D KRAS mutation, signifying its superiority over alternative mutation detection approaches. The designed Lab-on-a-Disc system demonstrated exceptional preclinical and technical precision, accuracy, and versatility. By applying varying cutoff values to PNA- LB LAMP reactions, the assay's sensitivity and specificity were increased by 80 % and 90 %, respectively. The device's key advantages include a robust microfluidic Lab-on-a-Disc design, precise rotary control, and a cutting-edge induction heating module. These features enable multiplexing of LAMP reactions with high reproducibility and repeatability, with CV% values less than 3.5 % and 5.5 %, respectively. The device offers several methods for accurate endpoint result detection, including naked-eye observation, RGB image analysis using Python code, and time of fluorescence (Tf) values. Preclinical specificity and sensitivity, assessed using different cutoffs for Eva-Green fluorescence Tf values and pH-sensitive dyes, demonstrated comparable performance to the best standard methods. Overall, this study represents a significant step towards tailoring treatment strategies for cancer patients through precise and efficient mutation detection technologies.
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Affiliation(s)
- Maryam Sadat Mirlohi
- Clinical Biochemistry Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Esmail Pishbin
- Bio-microfluidics Laboratory, Department of Electrical Engineering and Information Technology, Iranian Research Organization for Science and Technology, Tehran, Iran.
| | - Rasool Dezhkam
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran; Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Mohammad Javad Kiani
- School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran
| | - Amir Shamloo
- Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
| | - Siamak Salami
- Clinical Biochemistry Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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2
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Ellenbroek BD, Kahler JP, Evers SR, Pomplun SJ. Synthetic Peptides: Promising Modalities for the Targeting of Disease-Related Nucleic Acids. Angew Chem Int Ed Engl 2024; 63:e202401704. [PMID: 38456368 DOI: 10.1002/anie.202401704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 03/09/2024]
Abstract
DNA and RNA play pivotal roles in life processes by storing and transferring genetic information, modulating gene expression, and contributing to essential cellular machinery such as ribosomes. Dysregulation and mutations in nucleic acid-related processes are implicated in numerous diseases. Despite the critical impact on health of nucleic acid mutations or dysregulation, therapeutic compounds addressing these biomolecules remain limited. Peptides have emerged as a promising class of molecules for biomedical research, offering potential solutions for challenging drug targets. This review focuses on the use of synthetic peptides to target disease-related nucleic acids. We discuss examples of peptides targeting double-stranded DNA, including the clinical candidate Omomyc, and compounds designed for regulatory G-quadruplexes. Further, we provide insights into both library-based screenings and the rational design of peptides to target regulatory human RNA scaffolds and viral RNAs, emphasizing the potential of peptides in addressing nucleic acid-related diseases.
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Affiliation(s)
| | | | - Sophie R Evers
- Leiden University, 2333 CC, Leiden, The Netherlands
- Present address, Department of Chemistry, University of Zurich, Wintherthurerstrasse 190, 8057, Zurich, Switzerland
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3
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Westerlund K, Oroujeni M, Gestin M, Clinton J, Hani Rosly A, Tano H, Vorobyeva A, Orlova A, Eriksson Karlström A, Tolmachev V. Shorter Peptide Nucleic Acid Probes Improve Affibody-Mediated Peptide Nucleic Acid-Based Pretargeting. ACS Pharmacol Transl Sci 2024; 7:1595-1611. [PMID: 38751640 PMCID: PMC11091976 DOI: 10.1021/acsptsci.4c00106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/28/2024] [Accepted: 04/10/2024] [Indexed: 05/18/2024]
Abstract
Affibody-mediated PNA-based pretargeting shows promise for HER2-expressing tumor radiotherapy. In our recent study, a 15-mer ZHER2:342-HP15 affibody-PNA conjugate, in combination with a shorter 9-mer [177Lu]Lu-HP16 effector probe, emerged as the most effective pretargeting strategy. It offered a superior tumor-to-kidney uptake ratio and more efficient tumor targeting compared to longer radiolabeled effector probes containing 12 or 15 complementary PNA bases. To enhance the production efficiency of our pretargeting system, we here introduce even shorter 6-, 7-, and 8-mer secondary probes, designated as HP19, HP21, and HP20, respectively. We also explore the replacement of the original 15-mer Z-HP15 primary probe with shorter 12-mer Z-HP12 and 9-mer Z-HP9 alternatives. This extended panel of shorter PNA-based probes was synthesized using automated microwave-assisted methods and biophysically screened in vitro to identify shorter probe combinations with the most effective binding properties. In a mouse xenograft model, we evaluated the biodistribution of these probes, comparing them to the Z-HP15:[177Lu]Lu-HP16 combination. Tumor-to-kidney ratios at 4 and 144 h postinjection of the secondary probe showed no significant differences among the Z-HP9:[177Lu]Lu-HP16, Z-HP9:[177Lu]Lu-HP20, and the Z-HP15:[177Lu]Lu-HP16 pairs. Importantly, tumor uptake significantly exceeded, by several hundred-fold, that of most normal tissues, with kidney uptake being the critical organ for radiation therapy. This suggests that using a shorter 9-mer primary probe, Z-HP9, in combination with 9-mer HP16 or 8-mer HP20 secondary probes effectively targets tumors while minimizing the dose-limiting kidney uptake of radionuclide. In conclusion, the Z-HP9:HP16 and Z-HP9:HP20 probe combinations offer good prospects for both cost-effective production and efficient in vivo pretargeting of HER2-expressing tumors.
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Affiliation(s)
- Kristina Westerlund
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Maryam Oroujeni
- Department
of Immunology, Genetics and
Pathology, Uppsala University, Uppsala 751 23, Sweden
- Affibody
AB, Solna 171
65, Sweden
| | - Maxime Gestin
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Jacob Clinton
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Alia Hani Rosly
- Department
of Immunology, Genetics and
Pathology, Uppsala University, Uppsala 751 23, Sweden
| | - Hanna Tano
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Anzhelika Vorobyeva
- Department
of Immunology, Genetics and
Pathology, Uppsala University, Uppsala 751 23, Sweden
| | - Anna Orlova
- Department
of Medicinal Chemistry, Uppsala University, Uppsala 751 23, Sweden
| | - Amelie Eriksson Karlström
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, Stockholm 106 91, Sweden
| | - Vladimir Tolmachev
- Department
of Immunology, Genetics and
Pathology, Uppsala University, Uppsala 751 23, Sweden
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4
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Aman R, Syed MM, Saleh A, Melliti F, Gundra S, Wang Q, Marsic T, Mahas A, Mahfouz M. Peptide nucleic acid-assisted generation of targeted double-stranded DNA breaks with T7 endonuclease I. Nucleic Acids Res 2024; 52:3469-3482. [PMID: 38421613 PMCID: PMC11014363 DOI: 10.1093/nar/gkae148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 02/14/2024] [Accepted: 02/18/2024] [Indexed: 03/02/2024] Open
Abstract
Gene-editing technologies have revolutionized biotechnology, but current gene editors suffer from several limitations. Here, we harnessed the power of gamma-modified peptide nucleic acids (γPNAs) to facilitate targeted, specific DNA invasion and used T7 endonuclease I (T7EI) to recognize and cleave the γPNA-invaded DNA. Our data show that T7EI can specifically target PNA-invaded linear and circular DNA to introduce double-strand breaks (DSBs). Our PNA-Guided T7EI (PG-T7EI) technology demonstrates that T7EI can be used as a programmable nuclease capable of generating single or multiple specific DSBs in vitro under a broad range of conditions and could be potentially applied for large-scale genomic manipulation. With no protospacer adjacent motif (PAM) constraints and featuring a compact protein size, our PG-T7EI system will facilitate and expand DNA manipulations both in vitro and in vivo, including cloning, large-fragment DNA assembly, and gene editing, with exciting applications in biotechnology, medicine, agriculture, and synthetic biology.
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Affiliation(s)
- Rashid Aman
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Muntjeeb M Syed
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Ahmed Saleh
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Firdaws Melliti
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Sivakrishna Rao Gundra
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Qiaochu Wang
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Tin Marsic
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Ahmed Mahas
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
- Department of Genetics, Harvard University, Boston, MA 02115, USA
| | - Magdy M Mahfouz
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
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5
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MacLelland V, Kravitz M, Gupta A. Therapeutic and diagnostic applications of antisense peptide nucleic acids. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102086. [PMID: 38204913 PMCID: PMC10777018 DOI: 10.1016/j.omtn.2023.102086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Peptide nucleic acids (PNAs) are synthetic nucleic acid analogs with a neutral N-(2-aminoethyl) glycine backbone. PNAs possess unique physicochemical characteristics such as increased resistance to enzymatic degradation, ionic strength and stability over a wide range of temperatures and pH, and low intrinsic electrostatic repulsion against complementary target oligonucleotides. PNA has been widely used as an antisense oligonucleotide (ASO). Despite the favorable characteristics of PNA, in comparison with other ASO technologies, the use of antisense PNA for novel therapeutics has lagged. This review provides a brief overview of PNA, its antisense mechanisms of action, delivery strategies, and highlights successful applications of PNA, focusing on anti-pathogenic, anti-neurodegenerative disease, anti-cancer, and diagnostic agents. For each application, several studies are discussed focusing on the different target sites of the PNA, design of different PNAs and the therapeutic outcome in different cell lines and animal models. Thereafter, persisting limitations slowing the successful integration of antisense PNA therapeutics are discussed in order to highlight actionable next steps in the development and optimization of PNA as an ASO.
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Affiliation(s)
- Victoria MacLelland
- Department of Pharmaceutical Sciences, University of Saint Joseph, West Hartford, CT 06117, USA
| | - Madeline Kravitz
- Department of Pharmaceutical Sciences, University of Saint Joseph, West Hartford, CT 06117, USA
| | - Anisha Gupta
- Department of Pharmaceutical Sciences, University of Saint Joseph, West Hartford, CT 06117, USA
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6
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Sarkar S. Recent advancements in bionanomaterial applications of peptide nucleic acid assemblies. Biopolymers 2024; 115:e23567. [PMID: 37792292 DOI: 10.1002/bip.23567] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/02/2023] [Accepted: 09/19/2023] [Indexed: 10/05/2023]
Abstract
Peptide nucleic acid (PNA) is a unique combination of peptides and nucleic acids. PNA can exhibit hydrogen bonding interactions with complementary nucleobases like DNA/RNA. Also, its polyamide backbone allows easy incorporation of biomolecules like peptides and proteins to build hybrid molecular constructs. Because of chimeric structural properties, PNA has lots of potential to build diverse nanostructures. However, progress in the PNA material field is still immature compared with its massive applications in antisense oligonucleotide research. Examples of well-defined molecular assemblies have been reported with PNA amphiphiles, self-assembling guanine-PNA monomers/dimers, and PNA-decorated nucleic acids/ polymers/ peptides. All these works indicate the great potential of PNA to be used as bionanomaterials. The review summarizes the recent reports on PNA-based nanostructures and their versatile applications. Additionally, this review shares a perspective to promote a better understanding of controlling molecular assembly by the systematic structural modifications of PNA monomers.
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Affiliation(s)
- Srijani Sarkar
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
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7
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Katkevics M, MacKay JA, Rozners E. Triplex-forming peptide nucleic acids as emerging ligands to modulate structure and function of complex RNAs. Chem Commun (Camb) 2024; 60:1999-2008. [PMID: 38259187 PMCID: PMC10922694 DOI: 10.1039/d3cc05409h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Over the last three decades, our view of RNA has changed from a simple intermediate supporting protein synthesis to a major regulator of biological processes. In the expanding area of RNA research, peptide nucleic acid (PNA) is emerging as a promising ligand for triple-helical recognition of complex RNAs. As discussed in this feature article, the key advantages of PNAs are high sequence specificity and affinity for RNA (>10 fold higher than for DNA) that are difficult to achieve with small molecule ligands. Emerging studies demonstrate that triple-helical binding of PNAs can modulate biological function and control dynamic conformational equilibria of complex folded RNAs. These results suggest that PNA has a unique potential as a research tool and therapeutic compound targeting RNA. The remaining problems hampering advances in these directions are limitations of sequences that can be recognized by Hoogsteen triplexes (typically purine rich tracts), poor cellular uptake and bioavailability of PNA, and potential off-target effects in biological systems. Recent exciting studies are discussed that illustrate how synthetic nucleic acid chemistry provides innovative solutions for these problems.
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Affiliation(s)
- Martins Katkevics
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - James A MacKay
- Department of Chemistry and Biochemistry, Elizabethtown College, Elizabethtown, PA 17022, USA
| | - Eriks Rozners
- Department of Chemistry, Binghamton University, Binghamton, NY 13902, USA.
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8
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Kumpina I, Loubidi M, Rozners E. Comparison of 2-Aminopyridine and 4-Thiopseudisocytosine PNA Nucleobases for Hoogsteen Recognition of Guanosine in RNA. ACS OMEGA 2024; 9:7249-7254. [PMID: 38371848 PMCID: PMC10870399 DOI: 10.1021/acsomega.3c09775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/17/2024] [Accepted: 01/23/2024] [Indexed: 02/20/2024]
Abstract
Peptide nucleic acid (PNA) is emerging as a promising ligand for triple-helical recognition of folded biologically relevant RNA. Chemical modifications are actively being developed to achieve high affinity and sequence specificity under physiological conditions. In this study, we compared two modified PNA nucleobases, 2-aminopyridine (M) and 4-thiopseudisocytosine (L), as alternatives to protonated cytosine (unfavorable under physiological conditions), to form more stable triplets than C+·G-C. Both nucleobases formed M+·G-C and L·G-C triplets of similar stability; however, the L-modified PNAs showed somewhat reduced sequence specificity. In conclusion, M and L represent two alternative solutions to the problem of cytosine protonation in triple-helical recognition of RNA. In M, the pKa is increased to favor partial protonation, which improves solubility and cellular uptake of M-modified PNAs. In L, the sulfur substitution enhances favorable hydrophobic interactions, which may have advantages in avoiding off-target effects that may be caused by cationic modifications. However, our results showed that substituting Ms with Ls did not restore the sequence specificity of a PNA containing cationic groups.
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Affiliation(s)
- Ilze Kumpina
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Mohammed Loubidi
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
| | - Eriks Rozners
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, United States
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9
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Sakar S, Anderson CF, Schneider JP. The Design of a Participatory Peptide Nucleic Acid Duplex Crosslinker to Enhance the Stiffness of Self-Assembled Peptide Gels. Angew Chem Int Ed Engl 2024; 63:e202313507. [PMID: 38057633 PMCID: PMC10872331 DOI: 10.1002/anie.202313507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/27/2023] [Accepted: 12/06/2023] [Indexed: 12/08/2023]
Abstract
Herein, peptide nucleic acids (PNAs) are employed in the design of a participatory duplex PNA-peptide crosslinking agent. Biophysical and mechanical studies show that crosslinkers present during peptide assembly leading to hydrogelation participate in the formation of fibrils while simultaneously installing crosslinks into the higher-order network that constitutes the peptide gel. The addition of 2 mol % crosslinker into the assembling system results in a ~100 % increase in mechanical stiffness without affecting the rate of peptide assembly or the local morphology of fibrils within the gel network. Stiffness enhancement is realized by only affecting change in the elastic component of the viscoelastic gel. A synthesis of the PNA-peptide duplex crosslinkers is provided that allows facile variation in peptide composition and addresses the notorious hydrophobic content of PNAs. This crosslinking system represents a new tool for modulating the mechanical properties of peptide-based hydrogels.
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Affiliation(s)
- Srijani Sakar
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, 376 Boyles Street, Frederick, MD 21702, USA
| | - Caleb F Anderson
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, 376 Boyles Street, Frederick, MD 21702, USA
| | - Joel P Schneider
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, 376 Boyles Street, Frederick, MD 21702, USA
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10
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Singh G, Monga V. Peptide Nucleic Acids: Recent Developments in the Synthesis and Backbone Modifications. Bioorg Chem 2023; 141:106860. [PMID: 37748328 DOI: 10.1016/j.bioorg.2023.106860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 09/07/2023] [Accepted: 09/09/2023] [Indexed: 09/27/2023]
Abstract
Nucleic acid represents the ideal drug candidate for protein targets that are hard to target or against which drug development is not easy. Peptide nucleic acids (PNAs) are synthesized by attaching modified peptide backbones generally derived from repetitive N-2-aminoethyl glycine units in place of the regular phosphodiester backbone and represent synthetic impersonator of nucleic acids that offers an exciting research field due to their fascinating spectrum of biotechnological, diagnostic and potential therapeutic applications. The semi-rigid peptide nucleic acid backbone serves as a nearly-perfect template for attaching complimentary base pairs on DNA or RNA in a sequence-dependent manner as described by Watson-Crick models. PNAs and their analogues are endowed with exceptionally high affinity and specificity for receptor sites, essentially due to their polyamide backbone's uncharged and flexible nature. The present review compiled various strategies to modify the polypeptide backbone for improving the target selectivity and stability of the PNAs in the body. The investigated biological activities carried out on PNAs have also been summarized in the present review.
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Affiliation(s)
- Gurpreet Singh
- Department of Pharmaceutical Chemistry, ISF College of Pharmacy, GT Road, Ghal Kalan, Moga 142001, Punjab, India
| | - Vikramdeep Monga
- Department of Pharmaceutical Sciences and Natural Products, Central University of Punjab, VPO-Ghudda, Bathinda 151401, Punjab, India.
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11
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Talbott JM, Tessier BR, Harding EE, Walby GD, Hess KJ, Baskevics V, Katkevics M, Rozners E, MacKay JA. Improved Triplex-Forming Isoorotamide PNA Nucleobases for A-U Recognition of RNA Duplexes. Chemistry 2023; 29:e202302390. [PMID: 37647091 DOI: 10.1002/chem.202302390] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/24/2023] [Accepted: 08/30/2023] [Indexed: 09/01/2023]
Abstract
Four new isoorotamide (Io)-containing PNA nucleobases have been designed for A-U recognition of double helical RNA. New PNA monomers were prepared efficiently and incorporated into PNA nonamers for binding A-U in a PNA:RNA2 triplex. Isothermal titration calorimetry and UV thermal melting experiments revealed slightly improved binding affinity for singly modified PNA compared to known A-binding nucleobases. Molecular dynamics simulations provided further insights into binding of Io bases in the triple helix. Together, the data revealed interesting insights into binding modes including the notion that three Hoogsteen hydrogen bonds are unnecessary for strong selective binding of an extended nucleobase. Cationic monomer Io8 additionally gave the highest affinity observed for an A-binding nucleobase to date. These results will help inform future nucleobase design toward the goal of recognizing any sequence of double helical RNA.
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Affiliation(s)
- John M Talbott
- Department of Chemistry and Biochemistry, Elizabethtown College, Elizabethtown, PA 17022, USA
| | - Brandon R Tessier
- Department of Chemistry, Binghamton University, Binghamton, NY 13902, USA
| | - Emily E Harding
- Department of Chemistry and Biochemistry, Elizabethtown College, Elizabethtown, PA 17022, USA
| | - Grant D Walby
- Department of Chemistry and Biochemistry, Elizabethtown College, Elizabethtown, PA 17022, USA
| | - Kyle J Hess
- Department of Chemistry and Biochemistry, Elizabethtown College, Elizabethtown, PA 17022, USA
| | | | - Martins Katkevics
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - Eriks Rozners
- Department of Chemistry, Binghamton University, Binghamton, NY 13902, USA
| | - James A MacKay
- Department of Chemistry and Biochemistry, Elizabethtown College, Elizabethtown, PA 17022, USA
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12
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Mikame Y, Yamayoshi A. Recent Advancements in Development and Therapeutic Applications of Genome-Targeting Triplex-Forming Oligonucleotides and Peptide Nucleic Acids. Pharmaceutics 2023; 15:2515. [PMID: 37896275 PMCID: PMC10609763 DOI: 10.3390/pharmaceutics15102515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/15/2023] [Accepted: 10/19/2023] [Indexed: 10/29/2023] Open
Abstract
Recent developments in artificial nucleic acid and drug delivery systems present possibilities for the symbiotic engineering of therapeutic oligonucleotides, such as antisense oligonucleotides (ASOs) and small interfering ribonucleic acids (siRNAs). Employing these technologies, triplex-forming oligonucleotides (TFOs) or peptide nucleic acids (PNAs) can be applied to the development of symbiotic genome-targeting tools as well as a new class of oligonucleotide drugs, which offer conceptual advantages over antisense as the antigene target generally comprises two gene copies per cell rather than multiple copies of mRNA that are being continually transcribed. Further, genome editing by TFOs or PNAs induces permanent changes in the pathological genes, thus facilitating the complete cure of diseases. Nuclease-based gene-editing tools, such as zinc fingers, CRISPR-Cas9, and TALENs, are being explored for therapeutic applications, although their potential off-target, cytotoxic, and/or immunogenic effects may hinder their in vivo applications. Therefore, this review is aimed at describing the ongoing progress in TFO and PNA technologies, which can be symbiotic genome-targeting tools that will cause a near-future paradigm shift in drug development.
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Affiliation(s)
- Yu Mikame
- Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyomachi, Nagasaki 852-8521, Japan
| | - Asako Yamayoshi
- Graduate School of Biomedical Sciences, Nagasaki University, 1-14 Bunkyomachi, Nagasaki 852-8521, Japan
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13
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Tsylents U, Siekierska I, Trylska J. Peptide nucleic acid conjugates and their antimicrobial applications-a mini-review. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023; 52:533-544. [PMID: 37610696 PMCID: PMC10618302 DOI: 10.1007/s00249-023-01673-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/07/2023] [Accepted: 07/10/2023] [Indexed: 08/24/2023]
Abstract
Peptide nucleic acid (PNA) is a nucleic acid mimic with high specificity and binding affinity to natural DNA or RNA, as well as resistance to enzymatic degradation. PNA sequences can be designed to selectively silence gene expression, which makes PNA a promising tool for antimicrobial applications. However, the poor membrane permeability of PNA remains the main limiting factor for its applications in cells. To overcome this obstacle, PNA conjugates with different molecules have been developed. This mini-review focuses on covalently linked conjugates of PNA with cell-penetrating peptides, aminosugars, aminoglycoside antibiotics, and non-peptidic molecules that were tested, primarily as PNA carriers, in antibacterial and antiviral applications. The chemistries of the conjugation and the applied linkers are also discussed.
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Affiliation(s)
- Uladzislava Tsylents
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland
| | - Izabela Siekierska
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland.
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14
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Zheng H, Clausse V, Amarasekara H, Mazur SJ, Botos I, Appella DH. Variation of Tetrahydrofurans in Thyclotides Enhances Oligonucleotide Binding and Cellular Uptake of Peptide Nucleic Acids. JACS AU 2023; 3:1952-1964. [PMID: 37502163 PMCID: PMC10369417 DOI: 10.1021/jacsau.3c00198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 07/29/2023]
Abstract
Selective incorporation of conformational constraints into thyclotides can be used to modulate their binding to complementary oligonucleotides, increase polarity, and optimize uptake into HCT116 cells without assistance from moieties known to promote cell uptake. The X-ray structure and biophysical studies of a thyclotide-DNA duplex reveal that incorporation of tetrahydrofurans into an aegPNA backbone promotes a helical conformation that enhances binding to complementary DNA and RNA. Selective incorporation of tetrahydrofurans into the aegPNA backbone allows polarity to be increased incrementally so that uptake into HCT116 cells can be optimized. The enhanced binding, polarity, and cellular uptake properties of thyclotides were used to demonstrate effective inhibition of microRNA-21 in HCT116 cells.
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Affiliation(s)
- Hongchao Zheng
- Synthetic
Bioactive Molecules Section, Laboratory of Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), National Institutes of Health, 8 Center Drive, Room 404, Bethesda, Maryland 20892, United States
| | - Victor Clausse
- Synthetic
Bioactive Molecules Section, Laboratory of Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), National Institutes of Health, 8 Center Drive, Room 404, Bethesda, Maryland 20892, United States
| | - Harsha Amarasekara
- Synthetic
Bioactive Molecules Section, Laboratory of Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), National Institutes of Health, 8 Center Drive, Room 404, Bethesda, Maryland 20892, United States
| | - Sharlyn J. Mazur
- Laboratory
of Cell Biology, National Cancer Institute,
National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, United States
| | - Istvan Botos
- Laboratory
of Molecular Biology, National Institute
of Diabetes and Digestive and Kidney Diseases, National Institutes
of Health, Department of Health and Human Services, Bethesda, Maryland 20892, United States
| | - Daniel H. Appella
- Synthetic
Bioactive Molecules Section, Laboratory of Bioorganic Chemistry (LBC), National Institute of Diabetes and Digestive and Kidney
Diseases (NIDDK), National Institutes of Health, 8 Center Drive, Room 404, Bethesda, Maryland 20892, United States
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15
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Ryan C, Rahman MM, Kumar V, Rozners E. Triplex-Forming Peptide Nucleic Acid Controls Dynamic Conformations of RNA Bulges. J Am Chem Soc 2023; 145:10497-10504. [PMID: 37155726 PMCID: PMC10198159 DOI: 10.1021/jacs.2c12488] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Indexed: 05/10/2023]
Abstract
RNA folding is driven by the formation of double-helical segments interspaced by loops of unpaired nucleotides. Among the latter, bulges formed by one or several unpaired nucleotides are one of the most common structural motifs that play an important role in stabilizing RNA-RNA, RNA-protein, and RNA-small molecule interactions. Single-nucleotide bulges can fold in alternative structures where the unpaired nucleobase is either looped-out (flexible) in a solvent or stacked-in (intercalated) between the base pairs. In the present study, we discovered that triplex-forming peptide nucleic acids (PNAs) had unusually high affinity for single-purine-nucleotide bulges in double-helical RNA. Depending on the PNA's sequence, the triplex formation shifted the equilibrium between looped-out and stacked-in conformations. The ability to control the dynamic equilibria of RNA's structure will be an important tool for studying structure-function relationships in RNA biology and may have potential in novel therapeutic approaches targeting disease-related RNAs.
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Affiliation(s)
- Christopher
A. Ryan
- Department of Chemistry, The State
University of New York, Binghamton University, Binghamton, New York 13902, United States
| | - Md Motiar Rahman
- Department of Chemistry, The State
University of New York, Binghamton University, Binghamton, New York 13902, United States
| | - Vipin Kumar
- Department of Chemistry, The State
University of New York, Binghamton University, Binghamton, New York 13902, United States
| | - Eriks Rozners
- Department of Chemistry, The State
University of New York, Binghamton University, Binghamton, New York 13902, United States
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16
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Prout J, Tian M, Palladino A, Wright J, Thompson JF. LNA blockers for improved amplification selectivity. Sci Rep 2023; 13:4858. [PMID: 36964235 PMCID: PMC10038989 DOI: 10.1038/s41598-023-31871-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 03/20/2023] [Indexed: 03/26/2023] Open
Abstract
LNA-containing oligonucleotides bind DNA more tightly than standard DNA, so they can interact with targeted sequences and affect multiple processes. When a desired DNA is present at low concentrations relative to nearly identical undesired DNAs, LNAs can block amplification of unwanted DNAs. Using a short rAAV and synthetic DNA sequence as a model, we studied the length, number, and positioning of LNA bases to improve blocker effectiveness. Oligonucleotides 18-24 bases long with LNAs at every other position were most effective. Highly degenerate targets were used to characterize the impact of mismatches on blocking. Mismatches at LNA ends had little impact on blocking activity. Single and double mismatches were tolerated with longer blockers, especially if the mismatches were near LNA ends. Shorter LNAs were more selective, with > 1 mismatch preventing effective blocking. Neither the strand to which a blocker bound nor the distance between the blocker and priming sites greatly impacted blocking efficiency. We used these findings to design blockers of wild-type DNA versus the single-base A1AT PiZ allele. Blockers are most specific when the mismatch is located away from the LNA 5' end. Pairs of partially overlapping blockers on opposite strands with a centrally-located mismatch have maximal activity and specificity.
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Affiliation(s)
- Jaime Prout
- Department of Genomics and Computational Biology, Homology Medicines, Inc., Bedford, MA, 01730, USA
| | - Michael Tian
- Department of Genomics and Computational Biology, Homology Medicines, Inc., Bedford, MA, 01730, USA
| | - Alicia Palladino
- Department of Genomics and Computational Biology, Homology Medicines, Inc., Bedford, MA, 01730, USA
| | - Jason Wright
- Department of Genomics and Computational Biology, Homology Medicines, Inc., Bedford, MA, 01730, USA
| | - John F Thompson
- Department of Genomics and Computational Biology, Homology Medicines, Inc., Bedford, MA, 01730, USA.
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17
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Imiołek M, Winssinger N. Two-Helix Supramolecular Proteomimetic Binders Assembled via PNA-Assisted Disulfide Crosslinking. Chembiochem 2023; 24:e202200561. [PMID: 36349499 DOI: 10.1002/cbic.202200561] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 11/05/2022] [Indexed: 11/10/2022]
Abstract
Peptidic motifs folded in a defined conformation are able to inhibit protein-protein interactions (PPIs) covering large interfaces and as such they are biomedical molecules of interest. Mimicry of such natural structures with synthetically tractable constructs often requires complex scaffolding and extensive optimization to preserve the fidelity of binding to the target. Here, we present a novel proteomimetic strategy based on a 2-helix binding motif that is brought together by hybridization of peptide nucleic acids (PNA) and stabilized by a rationally positioned intermolecular disulfide crosslink. Using a solid phase synthesis approach (SPPS), the building blocks are easily accessible and such supramolecular peptide-PNA helical hybrids could be further coiled using precise templated chemistry. The elaboration of the structural design afforded high affinity SARS CoV-2 RBD (receptor binding domain) binders without interference with the underlying peptide sequence, creating a basis for a new architecture of supramolecular proteomimetics.
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Affiliation(s)
- Mateusz Imiołek
- Department of Organic Chemistry, Faculty of Science, NCCR Chemical Biology, University of Geneva, 1211, Geneva, Switzerland
| | - Nicolas Winssinger
- Department of Organic Chemistry, Faculty of Science, NCCR Chemical Biology, University of Geneva, 1211, Geneva, Switzerland
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18
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Factors Impacting Invader-Mediated Recognition of Double-Stranded DNA. MOLECULES (BASEL, SWITZERLAND) 2022; 28:molecules28010127. [PMID: 36615321 PMCID: PMC9821881 DOI: 10.3390/molecules28010127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 12/28/2022]
Abstract
The development of chemically modified oligonucleotides enabling robust, sequence-unrestricted recognition of complementary chromosomal DNA regions has been an aspirational goal for scientists for many decades. While several groove-binding or strand-invading probes have been developed towards this end, most enable recognition of DNA only under limited conditions (e.g., homopurine or short mixed-sequence targets, low ionic strength, fully modified probe strands). Invader probes, i.e., DNA duplexes modified with +1 interstrand zippers of intercalator-functionalized nucleotides, are predisposed to recognize DNA targets due to their labile nature and high affinity towards complementary DNA. Here, we set out to gain further insight into the design parameters that impact the thermal denaturation properties and binding affinities of Invader probes. Towards this end, ten Invader probes were designed, and their biophysical properties and binding to model DNA hairpins and chromosomal DNA targets were studied. A Spearman's rank-order correlation analysis of various parameters was then performed. Densely modified Invader probes were found to result in efficient recognition of chromosomal DNA targets with excellent binding specificity in the context of denaturing or non-denaturing fluorescence in situ hybridization (FISH) experiments. The insight gained from the initial phase of this study informed subsequent probe optimization, which yielded constructs displaying improved recognition of chromosomal DNA targets. The findings from this study will facilitate the design of efficient Invader probes for applications in the life sciences.
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19
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Emehiser RG, Dhuri K, Shepard C, Karmakar S, Bahal R, Hrdlicka PJ. Serine-γPNA, Invader probes, and chimeras thereof: three probe chemistries that enable sequence-unrestricted recognition of double-stranded DNA. Org Biomol Chem 2022; 20:8714-8724. [PMID: 36285843 PMCID: PMC9707317 DOI: 10.1039/d2ob01567f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2023]
Abstract
Three probe chemistries are evaluated with respect to thermal denaturation temperatures, UV-Vis and fluorescence characteristics, recognition of complementary and mismatched DNA hairpin targets, and recognition of chromosomal DNA targets in the context of non-denaturing fluorescence in situ hybridization (nd-FISH) experiments: (i) serine-γPNAs (SγPNAs), i.e., single-stranded peptide nucleic acid (PNA) probes that are modified at the γ-position with (R)-hydroxymethyl moieties, (ii) Invader probes, i.e., DNA duplexes modified with +1 interstrand zippers of 2'-O-(pyren-1-yl)methyl-RNA monomers, a molecular arrangement that results in a violation of the neighbor exclusion principle, and (iii) double-stranded chimeric SγPNAs:Invader probes, i.e., duplexes between complementary SγPNA and Invader strands, which are destabilized due to the poor compatibility between intercalators and PNA:DNA duplexes. Invader probes resulted in efficient, highly specific, albeit comparatively slow recognition of the model DNA hairpin targets. Recognition was equally efficient and faster with the single-stranded SγPNA probes but far less specific, whilst the double-stranded chimeric SγPNAs:Invader probes displayed recognition characteristics that were intermediate of the parent probes. All three probe chemistries demonstrated the capacity to target chromosomal DNA in nd-FISH experiments, with Invader probes resulting in the most favorable and consistent characteristics (signals in >90% of interphase nuclei against a low background and no signal in negative control experiments). These probe chemistries constitute valuable additions to the molecular toolbox needed for DNA-targeting applications.
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Affiliation(s)
| | - Karishma Dhuri
- Pharmaceutical Sciences, University of Connecticut, Storrs, CT-06269, USA
| | - Caroline Shepard
- Department of Chemistry, University of Idaho, Moscow, ID-83844, USA.
| | - Saswata Karmakar
- Department of Chemistry, University of Idaho, Moscow, ID-83844, USA.
| | - Raman Bahal
- Pharmaceutical Sciences, University of Connecticut, Storrs, CT-06269, USA
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20
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Kulkarni P, Datta D, Ganesh KN. Gemdimethyl Peptide Nucleic Acids (α/β/γ -gdm-PNA): E/Z-Rotamers Influence the Selectivity in the Formation of Parallel/Antiparallel gdm-PNA:DNA/RNA Duplexes. ACS OMEGA 2022; 7:40558-40568. [PMID: 36385799 PMCID: PMC9647847 DOI: 10.1021/acsomega.2c05873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/17/2022] [Indexed: 05/29/2023]
Abstract
Peptide nucleic acids (PNAs) consist of an aminoethylglycine (aeg) backbone to which the nucleobases are linked through a tertiary amide group and bind to complementary DNA/RNA in a sequence-specific manner. The flexible aeg backbone has been the target for several chemical modifications of the PNA to improve its properties such as specificity, solubility, etc. PNA monomers exhibit a mixture of two rotamers (Z/E) arising from the restricted rotation around the tertiary amide N-CO bond. We have recently demonstrated that achiral gemdimethyl substitution at the α, β, and γ sites on the aeg backbone induces exclusive Z (α-gdm)- or E-rotamer (β-gdm) selectivity at the monomer level. It is now shown that γ/β-gdm-PNA:DNA parallel duplexes are more stable than the analogous antiparallel duplexes, while γ/β-gdm-PNA:RNA antiparallel duplexes are more stable than parallel duplexes. Furthermore, the γ/β-gdm-PNA:RNA duplexes are more stable than the γ/β-gdm-PNA:DNA duplexes. These results with γ/β-gdm-PNA are the reverse of those previously seen with α-gdm-PNA oligomers that stabilized antiparallel α-gdm-PNA:DNA duplexes compared to α-gdm-PNA:RNA duplexes. The stability of antiparallel/parallel PNA:DNA/RNA duplexes is correlated with the preference for Z/E-rotamer selectivity in α/β-gdm-PNA monomers, with Z-rotamers (α-gdm) leading to antiparallel duplexes and E-rotamers (β/γ-gdm) leading to parallel duplexes. The results highlight the role and importance of Z- and E-rotamers in controlling the structural preferences of PNA:DNA/RNA duplexes.
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Affiliation(s)
- Pradnya Kulkarni
- Chemistry
Department, Indian Institute of Science
Education and Research (IISER) Tirupati, Karkambadi Road, Mangalam, Tirupati517507, India
| | - Dhrubajyoti Datta
- Chemistry
Department, Indian Institute of Science
Education and Research (IISER) Tirupati, Karkambadi Road, Mangalam, Tirupati517507, India
| | - Krishna N. Ganesh
- Indian
Institute of Science Education and Research (IISER) Pune, Dr Homi Bhabha Road, Pune411008, India
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21
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Fluorescence ratiometric DNA detection by peptide nucleic acid-pyrene binary probes. Bioorg Med Chem Lett 2022; 71:128838. [PMID: 35654301 DOI: 10.1016/j.bmcl.2022.128838] [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: 04/01/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 11/23/2022]
Abstract
We developed a method for detecting DNA by excimer fluorescence from two peptide nucleic acids (PNAs) modified with a pyrene (Pyr). The two PNA-Pyr probes were prepared by solid-phase peptide synthesis, and we assessed fluorescence from the mixture of probes with DNA. From the results, excimer fluorescence derived from the two PNA-Pyr probes forming hybrids with the complementary DNA was observed, and the two probes showed the maximum excimer/monomer ratio when the probes and DNA were hybridized at a 1:1:1 ratio, indicating that the PNA-Pyr probes can detect target DNA. Furthermore, we adjusted the spatial arrangement between the two PNA-Pyr hybrids formed on the DNA to promote optimal excimer formation. As a result, optimal excimer formation was achieved by spacing the two nucleobases between the formed two hybrids and further inserting a hexamethylene linker (C6) between the PNA and Pyr of the PNA-Pyr probe on one side.
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22
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Ryan CA, Baskevics V, Katkevics M, Rozners E. 2-Guanidyl pyridine PNA nucleobase for triple-helical Hoogsteen recognition of cytosine in double-stranded RNA. Chem Commun (Camb) 2022; 58:7148-7151. [PMID: 35666682 DOI: 10.1039/d2cc02615e] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In triplex-forming peptide nucleic acid, a novel 2-guanidyl pyridine nucleobase (V) enables recognition of up to two cytosine interruptions in polypurine tracts of dsRNA by engaging the entire Hoogsteen face of C-G base pair. Ab initio and molecular dynamics simulations provided insights into H-bonding interactions that stabilized V·C-G triplets. Our results provided insights for future design of improved nucleobases, which is an important step towards the ultimate goal of recognition of any sequence of dsRNA.
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Affiliation(s)
- Christopher A Ryan
- Department of Chemistry, Binghamton University, Binghamton, NY 13902, USA.
| | | | - Martins Katkevics
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - Eriks Rozners
- Department of Chemistry, Binghamton University, Binghamton, NY 13902, USA.
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23
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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: 4] [Impact Index Per Article: 2.0] [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.
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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
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24
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Metal Complexes in Target-Specific Anticancer Therapy: Recent Trends and Challenges. J CHEM-NY 2022. [DOI: 10.1155/2022/9261683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Cancer is characterized by abnormal cell differentiation in or on the part of the body. The most commonly used chemotherapeutic drugs are developed to target rapidly dividing cells, such as cancer cells, but they also damage healthy epithelial cells. This has serious consequences for normal cells and become responsible for the development of various disorders. Several strategies for delivering the cytotoxic drugs to cancerous sites that limit systemic toxicity and other adverse effects have recently been evolved. Among them, biomolecule-conjugated metal complexes-based cancer targeting strategies have shown tremendous advantages in cancer therapy. This review focuses on several chemoselective biomolecules-bound metal complexes as prospective cancer therapy-targeted agents. In this review, we presented the details of the various extra- and intracellular targeting mechanisms in cancer therapy. We also addressed the current clinical issues and recent therapeutic strategies in targeted cancer therapy that may pave a way for the future direction of metal complexes-based targeted cancer therapy.
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25
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Asandei A, Mereuta L, Bucataru IC, Park Y, Luchian T. A single-molecule insight into the ionic strength dependent, cationic peptide nucleic acids - oligonucleotides interactions. Chem Asian J 2022; 17:e202200261. [PMID: 35419929 DOI: 10.1002/asia.202200261] [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: 03/14/2022] [Revised: 04/12/2022] [Indexed: 11/08/2022]
Abstract
To alleviate solubility-related shortcomings associated with the use of neutral peptide nucleic acids (PNA), a powerful strategy is incorporate various charged sidechains onto the PNA structure. Here we employ a single-molecule technique and prove that the ionic current blockade signature of free poly(Arg)-PNAs and their corresponding duplexes with target ssDNAs interacting with a single a-hemolysin (a-HL) nanopore is highly ionic strength dependent, with high salt-containing electrolytes facilitating both capture and isolation of such complexes. Our data illustrate the effect of low ionic strength in reducing the effective volume of free poly(Arg)-PNAs and augmentation of their electrophoretic mobility while traversing the nanopore. We found that unlike in high salt electrolytes, the specific hybridization of cationic moiety-containing PNAs with complementary negatively charged ssDNAs in a salt concentration as low as 0.5 M is dramatically impeded. We suggest a scenario in which reduced charge screening by counterions in low salt electrolytes enables non-specific, electrostatic interactions with the anionic backbone of polynucleotides, thus reducing the ability of PNA-DNA complementary association via hydrogen bonding patterns. We applied an experimental strategy with spatially-separated poly(Arg)-PNAs and ssDNAs, and present evidence at the single-molecule level suggestive of the real-time, long-range interactions-driven formation of poly(Arg)-PNA-DNA complexes, as individual strands entering the nanopore from opposite directions collide inside a nanocavity.
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Affiliation(s)
- Alina Asandei
- Alexandru Ioan Cuza University: Universitatea Alexandru Ioan Cuza, ICI, ROMANIA
| | - Loredana Mereuta
- Alexandru Ioan Cuza University: Universitatea Alexandru Ioan Cuza, Physics, ROMANIA
| | - Ioana C Bucataru
- Alexandru Ioan Cuza University: Universitatea Alexandru Ioan Cuza, Physics, ROMANIA
| | - Yoonkyung Park
- Chosun University, Department of Biomedical Science, ROMANIA
| | - Tudor Luchian
- Alexandru I. Cuza University, Physics, Blvd. Carol I, no. 11, 700506, Iasi, ROMANIA
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26
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Kumar V, Rozners E. Fluorobenzene Nucleobase Analogues for Triplex-Forming Peptide Nucleic Acids. Chembiochem 2022; 23:e202100560. [PMID: 34889020 PMCID: PMC8935525 DOI: 10.1002/cbic.202100560] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/24/2021] [Indexed: 02/06/2023]
Abstract
2,4-Difluorotoluene is a nonpolar isostere of thymidine that has been used as a powerful mechanistic probe to study the role of hydrogen bonding in nucleic acid recognition and interactions with polymerases. In the present study, we evaluated five fluorinated benzenes as nucleobase analogues in peptide nucleic acids designed for triple helical recognition of double helical RNA. We found that analogues having para and ortho fluorine substitution patterns (as in 2,4-difluorotoluene) selectively stabilized Hoogsteen triplets with U-A base pairs. The results were consistent with attractive electrostatic interactions akin to non-canonical F to H-N and C-H to N hydrogen bonding. The fluorinated nucleobases were not able to stabilize Hoogsteen-like triplets with pyrimidines in either G-C or A-U base pairs. Our results illustrate the ability of fluorine to engage in non-canonical base pairing and provide insights into triple helical recognition of RNA.
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Affiliation(s)
- Vipin Kumar
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, USA
| | - Eriks Rozners
- Department of Chemistry, Binghamton University, Binghamton, New York 13902, USA
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27
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Adhikari SP, Karmakar S, Hrdlicka PJ. Nicked Invader probes: multistranded and sequence-unrestricted recognition of double-stranded DNA. Org Biomol Chem 2022; 20:1019-1030. [PMID: 34874037 PMCID: PMC8810728 DOI: 10.1039/d1ob02019f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Major efforts have been devoted to the development of constructs that enable sequence-specific recognition of double-stranded (ds) DNA, fueled by the promise for enabling tools for applications in molecular biology, diagnostics, and medicine. Towards this end, we have previously introduced Invader probes, i.e., short DNA duplexes with +1 interstrand zipper arrangements of intercalator-functionalized nucleotides. The individual strands of these labile probes display high affinity towards complementary DNA (cDNA), which drives sequence-unrestricted dsDNA-recognition. However, recognition of long targets is challenging due to the high stability of the corresponding probes. To address this, we recently introduced toehold Invader probes, i.e., Invader probes with 5'-single-stranded overhangs. The toehold architecture allows for shorter double-stranded segments to be used, which facilitates probe dissociation and dsDNA-recognition. As an extension thereof, we here report the biophysical and dsDNA-targeting properties of nicked Invader probes. In this probe architecture, the single-stranded overhangs of toehold Invader probes are hybridized to short intercalator-modified auxiliary strands, leading to formation of additional labile segments. The extra binding potential from the auxiliary strands imparts nicked Invader probes with greater dsDNA-affinity than the corresponding toehold or blunt-ended probes. Recognition of chromosomal DNA targets, refractory to recognition by conventional Invader probes, is demonstrated for nicked Invader probes in the context of non-denaturing FISH experiments, which highlights their utility as dsDNA-targeting tools.
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Affiliation(s)
- Shiva P Adhikari
- Department of Chemistry, University of Idaho, Moscow, ID-83844, USA.
| | - Saswata Karmakar
- Department of Chemistry, University of Idaho, Moscow, ID-83844, USA.
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28
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Adhikari SP, Vukelich P, Guenther DC, Karmakar S, Hrdlicka PJ. Recognition of double-stranded DNA using LNA-modified toehold Invader probes. Org Biomol Chem 2021; 19:9276-9290. [PMID: 34657934 PMCID: PMC8625219 DOI: 10.1039/d1ob01888d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Development of molecules capable of binding to specific sequences of double-stranded (ds) DNA continues to attract considerable interest, as this may yield useful tools for applications in life science, biotechnology, and medicine. We have previously demonstrated sequence-unrestricted of dsDNA using Invader probes, i.e., DNA duplexes that are energetically activated through incorporation of +1 interstrand zipper arrangements of O2'-intercalator-functionalized RNA monomers. Nonetheless, recognition of extended dsDNA target regions remains challenging due to the high stability of the corresponding probes. To address this, we introduce toehold Invader probes, i.e., Invader probes with 5'-single-stranded overhangs. This design provides access to probes with shortened double-stranded segments, which facilitates probe denaturation. The single-stranded overhangs can, furthermore, be modified with affinity-enhancing modifications like LNA (locked nucleic acid) monomers to additionally increase target affinity. Herein, we report the biophysical and dsDNA-targeting properties of different toehold Invader designs and compare them to conventional Invader probes. LNA-modified toehold Invader probes display promising recognition characteristics, including greatly improved affinity to dsDNA, excellent binding specificity, and fast recognition kinetics, which enabled recognition of chromosomal DNA targets that have proven refractory to recognition by conventional Invader probes. Thus, toehold Invader probes represent another step toward a robust, oligonucleotide-based approach for sequence-unrestricted dsDNA-recognition.
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Affiliation(s)
- Shiva P Adhikari
- Department of Chemistry, University of Idaho, Moscow, ID-83844, USA.
| | - Philip Vukelich
- Department of Chemistry, University of Idaho, Moscow, ID-83844, USA.
| | - Dale C Guenther
- Department of Chemistry, University of Idaho, Moscow, ID-83844, USA.
| | - Saswata Karmakar
- Department of Chemistry, University of Idaho, Moscow, ID-83844, USA.
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