1
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Zhan X, Deng L, Lian Y, Shu Z, Xu Y, Mai X, Krishna MS, Lu R, Wang A, Bai S, Zhou F, Xiong C, Xu Y, Ni J, Vandana JJ, Wang Z, Li Y, Sun D, Huang S, Liu J, Cheng GJ, Wu S, Chiang YC, Stjepanovic G, Jiang C, Shao Y, Chen G. Enhanced Recognition of a Herbal Compound Epiberberine by a DNA Quadruplex-Duplex Structure. Anal Chem 2024. [PMID: 39093925 DOI: 10.1021/acs.analchem.4c02054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
The small molecule epiberberine (EPI) is a natural alkaloid with versatile bioactivities against several diseases including cancer and bacterial infection. EPI can induce the formation of a unique binding pocket at the 5' side of a human telomeric G-quadruplex (HTG) sequence with four telomeric repeats (Q4), resulting in a nanomolar binding affinity (KD approximately 26 nM) with significant fluorescence enhancement upon binding. It is important to understand (1) how EPI binding affects HTG structural stability and (2) how enhanced EPI binding may be achieved through the engineering of the DNA binding pocket. In this work, the EPI-binding-induced HTG structure stabilization effect was probed by a peptide nucleic acid (PNA) invasion assay in combination with a series of biophysical techniques. We show that the PNA invasion-based method may be useful for the characterization of compounds binding to DNA (and RNA) structures under physiological conditions without the need to vary the solution temperature or buffer components, which are typically needed for structural stability characterization. Importantly, the combination of theoretical modeling and experimental quantification allows us to successfully engineer Q4 derivative Q4-ds-A by a simple extension of a duplex structure to Q4 at the 5' end. Q4-ds-A is an excellent EPI binder with a KD of 8 nM, with the binding enhancement achieved through the preformation of a binding pocket and a reduced dissociation rate. The tight binding of Q4 and Q4-ds-A with EPI allows us to develop a novel magnetic bead-based affinity purification system to effectively extract EPI from Rhizoma coptidis (Huang Lian) extracts.
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Affiliation(s)
- Xuan Zhan
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Liping Deng
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Yun Lian
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Zhiyu Shu
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore
| | - Yunong Xu
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Xinyi Mai
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Manchugondanahalli S Krishna
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371 Singapore
| | - Rongguang Lu
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Anni Wang
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Shiyao Bai
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Fangyu Zhou
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Chi Xiong
- MinJiang Collaborative Center for Theoretical Physics, College of Physics and Electronic Information Engineering, Minjiang University, Fuzhou 350108, Fujian, P. R. China
| | - Yingyi Xu
- LightEdge Technologies Ltd., Zhongshan 528400, Guangdong, P. R. China
| | - Jie Ni
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - J Jeya Vandana
- Department of Surgery, Weill Cornell Medicine, New York, New York 10065, United States
- Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medicine, Memorial Sloan Kettering Cancer Center, The Rockefeller University, New York, New York 10065, United States
| | - Zi Wang
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Yuqing Li
- Department of Urology, South China Hospital of Shenzhen University, Shenzhen 518111, Guangdong, P. R. China
| | - Dongmei Sun
- Guangdong Yifang Pharmaceutical, Foshan 528244, Guangdong, P. R. China
| | - Shaohui Huang
- School of Life Sciences, University of Chinese Academy of Sciences, Beijing 101499, P. R. China
| | - Jingyan Liu
- School of Medicine, The Second Affiliated Hospital, The Chinese University of Hong Kong, Shenzhen 518172, Guangdong, P. R. China
| | - Gui-Juan Cheng
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Song Wu
- Department of Urology, South China Hospital of Shenzhen University, Shenzhen 518111, Guangdong, P. R. China
| | - Ying-Chih Chiang
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Goran Stjepanovic
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Cheng Jiang
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
| | - Yong Shao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, Zhejiang, P. R. China
| | - Gang Chen
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, P. R. China
- Shenzhen Key Laboratory of Innovative Drug Synthesis, The Chinese University of Hong Kong, Shenzhen 518172, P. R. China
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2
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Mandal S, Ganesh KN, Maiti PK. Dynamics of terminal fraying-peeling and hydrogen bonds dictates the sequential vs. cooperative melting pathways of nanoscale DNA and PNA triplexes. NANOSCALE 2024; 16:13029-13040. [PMID: 38904319 DOI: 10.1039/d4nr01104j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Peptide nucleic acids (PNAs) are charge-neutral synthetic DNA/RNA analogues. In many aspects of biology and biotechnology, the details of DNA and PNA melting reaction coordinates are crucial, and their associative/dissociative details remain inadequately understood. In the current study, we have attempted to gain insights into comparative melting pathways and binding affinity of iso-sequences of an 18-mer PNA-DNA-PNA triplex and the analogous DNA-DNA-DNA triplex, and DNA-DNA and PNA-DNA duplexes. It is intriguing that while the DNA-DNA-DNA triplex melts in two sequential steps, the PNA-DNA-PNA triplex melts in a single step and the mechanistic aspects for this difference are still not clear. We report an all-atom molecular dynamics simulation of both complexes in the temperature range of 300 to 500 K with 20 K intervals. Based on the trajectory analysis, we provide evidence that the association and dissociation are dictated by the differences in fraying-peeling effects from either terminus to the center in a zipper pattern among the PNA-DNA-PNA triplex and DNA-DNA-DNA triplexes. These are shown to be governed by the different characteristics of H-bonding, RMSD, and Free Energy Landscape (FEL) as analyzed by PCA, leading to the DNA-DNA-DNA triplex exhibiting sequential melting, while the PNA-DNA-PNA triplex shows cooperative melting of the whole fragment in a single-step. The PNA-DNA-PNA triplex base pairs are thermodynamically more stable than the DNA-DNA-DNA triplex, with the binding affinity of PNA-TFO to the PNA : DNA duplex being higher than that of DNA-TFO to the DNA : DNA duplex. The investigation of the association/dissociation of PNA-TFO to the PNA-DNA duplex has relevance and importance in the emerging effective applications of oligonucleotide therapy.
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Affiliation(s)
- Sandip Mandal
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India.
| | - Krishna N Ganesh
- Jawaharlal Nehru Center for Advanced Scientific Research (JNCASR), Jakkur, Bengaluru 560064, India.
| | - Prabal K Maiti
- Center for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India.
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3
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Saini S, Goel K, Ghosh S, Das A, Saraogi I. Effects of PNA Sequence and Target Site Selection on Function of a 4.5S Non-Coding RNA. Chembiochem 2024:e202400029. [PMID: 38595046 DOI: 10.1002/cbic.202400029] [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: 01/12/2024] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 04/11/2024]
Abstract
Peptide nucleic acid (PNA) based antisense strategy is a promising therapeutic approach to specifically inhibit target gene expression. However, unlike protein coding genes, identification of an ideal PNA binding site for non-coding RNA is not straightforward. Here, we compare the inhibitory activities of PNA molecules that bind a non-coding 4.5S RNA called SRP RNA, a key component of the bacterial signal recognition particle (SRP). A 9-mer PNA (PNA9) complementary to the tetraloop region of the RNA was more potent in inhibiting its interaction with the SRP protein, compared to an 8-mer PNA (PNA8) targeting a stem-loop. PNA9, which contained a homo-pyrimidine sequence could form a triplex with the complementary stretch of RNA in vitro as confirmed using a fluorescent derivative of PNA9 (F-PNA13). The RNA-PNA complex formation resulted in inhibition of SRP function with PNA9 and F-PNA13, but not PNA8 highlighting the importance of target site selection. Surprisingly, F-PNA13 which was more potent in inhibiting SRP function in vitro, showed weaker antibacterial activity compared to PNA9 likely due to poor cell penetration of the longer PNA. Our results underscore the importance of suitable target site selection and optimum PNA length to develop better antisense molecules against non-coding RNA.
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Affiliation(s)
- Snehlata Saini
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Khushboo Goel
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Sudipta Ghosh
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Anirban Das
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Ishu Saraogi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
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4
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Lu R, Chen G. Pre-twisting for improved genome modification and miRNA targeting. Trends Biochem Sci 2024; 49:283-285. [PMID: 38238217 DOI: 10.1016/j.tibs.2024.01.002] [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: 12/27/2023] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 04/07/2024]
Abstract
Two reports by Dhuri et al. and Oyaghire et al., respectively, show that, through installing chiral centers at the backbone of the artificial nucleic acid, peptide nucleic acid (PNA), enhanced miRNA targeting and genome modification can be achieved, with important implications in fighting cancers and β-thalassemia.
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Affiliation(s)
- Rongguang Lu
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, China; National Clinical Research Center for Infectious Diseases, The Third People's Hospital of Shenzhen, Shenzhen 518112, Guangdong, China
| | - Gang Chen
- School of Medicine, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, Guangdong, China.
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5
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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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6
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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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7
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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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8
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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: 3] [Impact Index Per Article: 3.0] [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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9
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Peng HC, Castro GL, Karthikeyan V, Jarrett A, Katz MA, Hargrove JA, Hoang D, Hilber S, Meng W, Wang L, Fick RJ, Ahn JM, Kreutz C, Stelling AL. Measuring the Enthalpy of an Individual Hydrogen Bond in a DNA Duplex with Nucleobase Isotope Editing and Variable-Temperature Infrared Spectroscopy. J Phys Chem Lett 2023; 14:4313-4321. [PMID: 37130045 DOI: 10.1021/acs.jpclett.3c00178] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The level of interest in probing the strength of noncovalent interactions in DNA duplexes is high, as these weak forces dictate the range of suprastructures the double helix adopts under different conditions, in turn directly impacting the biological functions and industrial applications of duplexes that require making and breaking them to access the genetic code. However, few experimental tools can measure these weak forces embedded within large biological suprastructures in the native solution environment. Here, we develop experimental methods for detecting the presence of a single noncovalent interaction [a hydrogen bond (H-bond)] within a large DNA duplex in solution and measure its formation enthalpy (ΔHf). We report that introduction of a H-bond into the TC2═O group from the noncanonical nucleobase 2-aminopurine produces an expected decrease ∼10 ± 0.76 cm-1 (from ∼1720 cm-1 in Watson-Crick to ∼1710 cm-1 in 2-aminopurine), which correlates with an enthalpy of ∼0.93 ± 0.066 kcal/mol for this interaction.
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Affiliation(s)
- Hao-Che Peng
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Gabrielle L Castro
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Varshini Karthikeyan
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Alina Jarrett
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Melanie A Katz
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - James A Hargrove
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - David Hoang
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Stefan Hilber
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck 6020, Austria
| | - Wenting Meng
- Department of Chemistry and Chemical Biology, Institute for Quantitative Biomedicine, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Lu Wang
- Department of Chemistry and Chemical Biology, Institute for Quantitative Biomedicine, Rutgers University, Piscataway, New Jersey 08854, United States
| | - Robert J Fick
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Jung-Mo Ahn
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Christoph Kreutz
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck 6020, Austria
| | - Allison L Stelling
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
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10
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Das A, Ghosh A, Sinha S. C5-pyrimidine-functionalized morpholino oligonucleotides exhibit differential binding affinity, target specificity and lipophilicity. Org Biomol Chem 2023; 21:1242-1253. [PMID: 36633261 DOI: 10.1039/d2ob01759h] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
C5-substituted uridine and cytidine morpholino chlorophosphoramidate monomers were synthesized and incorporated into a 12-mer Phosphorodiamidate Morpholino Oligonucleotide (PMO) using semi-automated solid phase synthesis. PMOs with most of the tested pyrimidine C5-substitutions have significantly increased thermal stability when bound to the complementary RNA strand relative to the PMO. They exhibit higher binding with RNA than DNA. CD-spectra show B-type helical conformation of duplexes. HPLC analysis indicates their greater lipophilicity compared to regular PMOs. These chemical modifications have significant potential towards the development of better antisense technologies.
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Affiliation(s)
- Arnab Das
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
| | - Atanu Ghosh
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
| | - Surajit Sinha
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
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11
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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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Therapeutic Strategies in Huntington’s Disease: From Genetic Defect to Gene Therapy. Biomedicines 2022; 10:biomedicines10081895. [PMID: 36009443 PMCID: PMC9405755 DOI: 10.3390/biomedicines10081895] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 12/14/2022] Open
Abstract
Despite the identification of an expanded CAG repeat on exon 1 of the huntingtin gene located on chromosome 1 as the genetic defect causing Huntington’s disease almost 30 years ago, currently approved therapies provide only limited symptomatic relief and do not influence the age of onset or disease progression rate. Research has identified various intricate pathogenic cascades which lead to neuronal degeneration, but therapies interfering with these mechanisms have been marked by many failures and remain to be validated. Exciting new opportunities are opened by the emerging techniques which target the mutant protein DNA and RNA, allowing for “gene editing”. Although some issues relating to “off-target” effects or immune-mediated side effects need to be solved, these strategies, combined with stem cell therapies and more traditional approaches targeting specific pathogenic cascades, such as excitotoxicity and bioavailability of neurotrophic factors, could lead to significant improvement of the outcomes of treated Huntington’s disease patients.
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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: 7] [Impact Index Per Article: 3.5] [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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