1
|
Roy S, Majee P, Sudhakar S, Mishra S, Kalia J, Pradeepkumar PI, Srivatsan SG. Structural elucidation of HIV-1 G-quadruplexes in a cellular environment and their ligand binding using responsive 19F-labeled nucleoside probes. Chem Sci 2024; 15:7982-7991. [PMID: 38817587 PMCID: PMC11134374 DOI: 10.1039/d4sc01755b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 04/23/2024] [Indexed: 06/01/2024] Open
Abstract
Understanding the structure and recognition of highly conserved regulatory segments of the integrated viral DNA genome that forms unique topologies can greatly aid in devising novel therapeutic strategies to counter chronic infections. In this study, we configured a probe system using highly environment-sensitive nucleoside analogs, 5-fluoro-2'-deoxyuridine (FdU) and 5-fluorobenzofuran-2'-deoxyuridine (FBFdU), to investigate the structural polymorphism of HIV-1 long terminal repeat (LTR) G-quadruplexes (GQs) by fluorescence and 19F NMR. FdU and FBFdU, serving as hairpin and GQ sensors, produced distinct spectral signatures for different GQ topologies adopted by LTR G-rich oligonucleotides. Importantly, systematic 19F NMR analysis in Xenopus laevis oocytes gave unprecedented information on the structure adopted by the LTR G-rich region in the cellular environment. The results indicate that it forms a unique GQ-hairpin hybrid architecture, a potent hotspot for selective targeting. Furthermore, structural models generated using MD simulations provided insights on how the probe system senses different GQs. Using the responsiveness of the probes and Taq DNA polymerase stop assay, we monitored GQ- and hairpin-specific ligand interactions and their synergistic inhibitory effect on the replication process. Our findings suggest that targeting GQ and hairpin motifs simultaneously using bimodal ligands could be a new strategy to selectively block the viral replication.
Collapse
Affiliation(s)
- Sarupa Roy
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune Dr Homi Bhabha Road Pune 411008 India
| | - Priyasha Majee
- Department of Chemistry, Indian Institute of Technology Bombay Mumbai 400076 India
| | - Sruthi Sudhakar
- Department of Chemistry, Indian Institute of Technology Bombay Mumbai 400076 India
| | - Satyajit Mishra
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal Bhopal Bypass Road, Bhauri Bhopal 462066 India
| | - Jeet Kalia
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal Bhopal Bypass Road, Bhauri Bhopal 462066 India
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal Bhopal Bypass Road, Bhauri Bhopal 462066 India
| | - P I Pradeepkumar
- Department of Chemistry, Indian Institute of Technology Bombay Mumbai 400076 India
| | - Seergazhi G Srivatsan
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune Dr Homi Bhabha Road Pune 411008 India
| |
Collapse
|
2
|
Metangle S, Ranjan N. Preferential Binding of a Red Emissive Julolidine Derivative to a Promoter G-Quadruplex. Chembiochem 2024; 25:e202300527. [PMID: 37926689 DOI: 10.1002/cbic.202300527] [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: 07/21/2023] [Revised: 10/23/2023] [Accepted: 11/02/2023] [Indexed: 11/07/2023]
Abstract
The therapeutic potential of G-quadruplexes has increased significantly with the growing understanding of their functional roles in pathogens apart from human diseases such as cancer. Here, we report the synthesis of three julolidine-based molecules and their binding to nucleic acids. Among the synthesized molecules, compound 1 exhibited red emissive fluorescence with a distinct preference for Pu22 G-quadruplex. The binding of compound 1 to Pu22 G-quadruplex, initially identified through a fluorescence-based screening, was further confirmed by UV-vis, fluorescence spectroscopy, and circular dichroism-based experiments. Thermal denaturation of compound 1 in the presence of Pu22 G-quadruplex revealed a concentration-dependent stabilization (~10.0 °C at 1 : 3 stoichiometry). Fluorescence-based experiments revealed 1 : 1 stoichiometry of the interaction and an association constant (Ka ) of 5.67×106 M-1 . CD experiments displayed that the parallel conformation of the G-quadruplex was retained on compound 1's binding and signs of higher order binding/complex formation were observed at high compound 1 to DNA ratio. Molecular docking studies revealed the dominance of stacking and van der Waals interactions in the molecular recognition which was aided by some close-distance interactions involving the quinolinium nitrogen atom.
Collapse
Affiliation(s)
- Sachin Metangle
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Raebareli, New Transit Campus, Lucknow, Uttar Pradesh, 226002, India
| | - Nihar Ranjan
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research-Raebareli, New Transit Campus, Lucknow, Uttar Pradesh, 226002, India
| |
Collapse
|
3
|
Hu Z, Wang D, Zhou Q, Jie J, Su H. Complexed Photosensitizer of Hypericin with G-Quadruplex: Structure-Dependent Behavior. J Phys Chem B 2024; 128:576-584. [PMID: 38189153 DOI: 10.1021/acs.jpcb.3c07307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Despite the increased interest of visible-light-absorbing compound Hypericin (Hyp) in photodiagnosis, photocatalysis, and photodynamic therapy (PDT) applications, a major obstacle still exists; i.e., the photoactivity is diminished due to the facile aggregation of Hyp in aqueous environment that induces excited-state quenching. Herein, we explore the excited-state property of Hyp bound to the DNA G-quadruplex by combining multiple steady-state and time-resolved spectroscopy. We find that the aggregation-induced quenching effect can be successfully prevented by appropriate G-quadruplex binders that disperse Hyp into monomer. The binding of Hyp/G-quadruplex is selective, however, exhibiting a preferential binding toward parallel G-quadruplexes (c-kit2, C14B1, STAT3, S50, and PS2.M), over antiparallel or hybrid G-quadruplex (Tel22, TBA). The excited-state property of Hyp is highly related to the binding behavior, showing a consistent trend that the better the Hyp/G-quadruplex binding, the longer the triplet 3Hyp* lifetime and the higher the efficiency to produce 1O2. For Hyp/c-kit2, the major binding mode is 5'-end stacking, which offers protection from collisional quenching reactions and ensures a stable photocycle of 3Hyp*-O2 energy transfer forming 1O2, leading to the highest 1O2 quantum yield (0.67) with superior photostability. These findings open possibilities of developing Hyp/G-quadruplex complex as a biocompatible photosensitizer for PDT applications, etc.
Collapse
Affiliation(s)
- Zheng Hu
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Danfeng Wang
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Qian Zhou
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Jialong Jie
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Hongmei Su
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| |
Collapse
|
4
|
Guo Z, Fan X, Wang X, Zhou Z, Zhang Y, Zhou N. Graphene oxide-enhanced colorimetric detection of Mec A gene based on toehold-mediated strand displacement. Anal Biochem 2024; 684:115365. [PMID: 37914003 DOI: 10.1016/j.ab.2023.115365] [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: 08/30/2023] [Revised: 10/08/2023] [Accepted: 10/20/2023] [Indexed: 11/03/2023]
Abstract
Mec A, as a representative gene mediating resistance to β-lactam antibiotics in methicillin-resistant Staphylococcus aureus (MRSA), allows a new genetic analysis for the detection of MRSA. Here, a sensitive, prompt, and visual colorimetry is reported to detect the Mec A gene based on toehold-mediated strand displacement (TMSD) and the enrichment effect of graphene oxide (GO). The Mec A triggers to generate the profuse amount of signal units of single-stranded DNA (SG) composed of a long single-stranded base tail and a base head: the tail can be adsorbed and enriched on the surface of GO; the head can form a G quadruplex structure to exert catalytic function towards 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid). Therefore, through the enrichment effect of GO, the signal units SG reflects different degrees of signal amplification on different substrates (such as aqueous solution or filter membrane). This strategy demonstrates a broad linear working range from 100 pM to 1.5 nM (solution) and 1 pM to 1 nM (filter membrane), with a low detection limit of 39.53 pM (solution) and 333 fM (filter membrane). Analytical performance in real samples suggests that this developed colorimetry is endowed with immense potential for clinical detection applications.
Collapse
Affiliation(s)
- Zongkang Guo
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Xueting Fan
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Xiaoli Wang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Zhemin Zhou
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
| | - Yuting Zhang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
| | - Nandi Zhou
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| |
Collapse
|
5
|
Ji D, Yuan JH, Chen SB, Tan JH, Kwok C. Selective targeting of parallel G-quadruplex structure using L-RNA aptamer. Nucleic Acids Res 2023; 51:11439-11452. [PMID: 37870474 PMCID: PMC10681708 DOI: 10.1093/nar/gkad900] [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: 06/05/2023] [Revised: 09/28/2023] [Accepted: 10/05/2023] [Indexed: 10/24/2023] Open
Abstract
G-quadruplexes (G4) are special nucleic acid structures with diverse conformational polymorphisms. Selective targeting of G-quadruplex conformations and regulating their biological functions provide promising therapeutic intervention. Despite the large repertoire of G4-binding tools, only a limited number of them can specifically target a particular G4 conformation. Here, we introduce a novel method, G4-SELEX-Seq and report the development of the first L-RNA aptamer, L-Apt12-6, with high binding selectivity to parallel G4 over other nucleic acid structures. Using parallel dG4 c-kit 1 as an example, we demonstrate the strong binding affinity between L-Apt12-6 and c-kit 1 dG4 in vitro and in cells, and notably report the applications of L-Apt12-6 in controlling DNA replication and gene expression. Our results suggest that L-Apt12-6 is a valuable tool for targeting parallel G-quadruplex conformation and regulating G4-mediated biological processes. Furthermore, G4-SELEX-Seq can be used as a general platform for G4-targeting L-RNA aptamers selection and should be applicable to other nucleic acid structures.
Collapse
Affiliation(s)
- Danyang Ji
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
| | - Jia-Hao Yuan
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Shuo-Bin Chen
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jia-Heng Tan
- Guangdong Provincial Key Laboratory of New Drug Design and Evaluation, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Chun Kit Kwok
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Hong Kong SAR, China
- Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| |
Collapse
|