1
|
Wang X, Xu N, Zhu L, Yang H, Li C, Tian H, Xu W. Structural Antagonism-Aided Conformational Regulation Enables an Aptamer-Loop G-Quadruplex Modular Sensor of β-Lactoglobulin. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2307995. [PMID: 38212277 DOI: 10.1002/smll.202307995] [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: 09/12/2023] [Revised: 12/13/2023] [Indexed: 01/13/2024]
Abstract
A simple, reliable method for identifying β-lactoglobulin (β-LG) in dairy products is needed to protect those with β-LG allergies. A common, practical strategy for target detection is designing simplified nucleic acid nanodevices by integrating functional components. This work presents a label-free modular β-LG aptasensor consisting of an aptamer-loop G-quadruplex (G4), the working conformation of which is regulated by conformational antagonism to ensure respective module functionality and the related signal transduction. The polymorphic conformations of the module-fused sequence are systematically characterized, and the cause is revealed as shifting antagonistic equilibrium. Combined with conformational folding dynamics, this helped regulate functional conformations by fine-tuning the sequences. Furthermore, the principle of specific β-LG detection by parallel G4 topology is examined as binding on the G4 aptamer loop by β-LG to reinforce the G4 topology and fluorescence. Finally, a label-free, assembly-free, succinct, and turn-on fluorescent aptasensor is established, achieving excellent sensitivity across five orders of magnitude, rapidly detecting β-LG within 22-min. This study provides a generalizable approach for the conformational regulation of module-fused G4 sequences and a reference model for creating simplified sensing devices for a variety of targets.
Collapse
Affiliation(s)
- Xinxin Wang
- College of Food Science and Technology, Hebei Agricultural University, Baoding, 071001, China
- College of Life Science and Engineering, Handan University, Handan, 056005, China
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Ning Xu
- School of Life Science, Tsinghua University, Beijing, 100091, China
| | - Longjiao Zhu
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - He Yang
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Chen Li
- College of Food Science and Technology, Hebei Agricultural University, Baoding, 071001, China
| | - Hongtao Tian
- College of Food Science and Technology, Hebei Agricultural University, Baoding, 071001, China
| | - Wentao Xu
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| |
Collapse
|
2
|
Ji C, Wei J, Zhang L, Hou X, Tan J, Yuan Q, Tan W. Aptamer-Protein Interactions: From Regulation to Biomolecular Detection. Chem Rev 2023; 123:12471-12506. [PMID: 37931070 DOI: 10.1021/acs.chemrev.3c00377] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Serving as the basis of cell life, interactions between nucleic acids and proteins play essential roles in fundamental cellular processes. Aptamers are unique single-stranded oligonucleotides generated by in vitro evolution methods, possessing the ability to interact with proteins specifically. Altering the structure of aptamers will largely modulate their interactions with proteins and further affect related cellular behaviors. Recently, with the in-depth research of aptamer-protein interactions, the analytical assays based on their interactions have been widely developed and become a powerful tool for biomolecular detection. There are some insightful reviews on aptamers applied in protein detection, while few systematic discussions are from the perspective of regulating aptamer-protein interactions. Herein, we comprehensively introduce the methods for regulating aptamer-protein interactions and elaborate on the detection techniques for analyzing aptamer-protein interactions. Additionally, this review provides a broad summary of analytical assays based on the regulation of aptamer-protein interactions for detecting biomolecules. Finally, we present our perspectives regarding the opportunities and challenges of analytical assays for biological analysis, aiming to provide guidance for disease mechanism research and drug discovery.
Collapse
Affiliation(s)
- Cailing Ji
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Junyuan Wei
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Lei Zhang
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Xinru Hou
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Jie Tan
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Quan Yuan
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Weihong Tan
- Molecular Science and Biomedicine Laboratory (MBL), State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
- The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, Zhejiang 310022, China
| |
Collapse
|
3
|
Johnson RE, Murray MT, Bycraft LJ, Myler P, Wetmore SD, Manderville RA. Harnessing a 4-Formyl-Aniline Handle to Tune the Stability of a DNA Aptamer-Protein Complex via Fluorescent Surrogates. Bioconjug Chem 2023; 34:2066-2076. [PMID: 37857354 DOI: 10.1021/acs.bioconjchem.3c00373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023]
Abstract
Interactions between DNA aptamers and protein targets hold promise for the development of pharmaceuticals and diagnostics. As such, the utilization of fluorescent nucleobase surrogates in studying aptamer-protein interactions is a powerful tool due to their ability to provide site-specific information through turn-on fluorescence. Unfortunately, previously described turn-on probes serving as nucleobase replacements have only been strongly disruptive to the affinity of aptamer-protein interactions. Herein, we present a modified TBA15 aptamer for thrombin containing a fluorescent surrogate that provides site-specific turn-on emission with low nanomolar affinity. The modification, referred to as AnBtz, was substituted at position T3 and provided strong turn-on emission (Irel ≈ 4) and brightness (ε·Φ > 20 000 cm-1 M-1) with an apparent dissociation constant (Kd) of 15 nM to afford a limit of detection (LOD) of 10 nM for thrombin in 20% human serum. The probe was selected through a modular "on-strand" synthesis process that utilized a 4-formyl-aniline (4FA) handle. Using this platform, we were able to enhance the affinity of the final aptamer conjugate by ∼30-fold in comparison with the initial conjugate design. Molecular dynamics simulations provide insight into the structural basis for this phenomenon and highlight the importance of targeting hydrophobic protein binding sites with fluorescent nucleobase surrogates to create new contacts with protein targets.
Collapse
Affiliation(s)
- Ryan E Johnson
- Departments of Chemistry & Toxicology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Makay T Murray
- Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Lucas J Bycraft
- Departments of Chemistry & Toxicology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Peter Myler
- Departments of Chemistry & Toxicology, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Stacey D Wetmore
- Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Richard A Manderville
- Departments of Chemistry & Toxicology, University of Guelph, Guelph, ON N1G 2W1, Canada
| |
Collapse
|
4
|
Babagond V, Katagi K, Pandith A, Akki M, Jaggal A. Unique development of a new dual application probe for selective detection of antiparallel G-quadruplex sequences. Analyst 2023; 148:5507-5513. [PMID: 37789760 DOI: 10.1039/d3an01109g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
G-Quadruplex (G4) structures play vital roles in many biological processes; consequently, they have been implicated in various human diseases like cancer, Alzheimer's disease etc. The selective detection of G4 DNA structures is of great interest for understanding their roles and biological functions. Hence, development of multifunctional fluorescent probes is indeed essential. In this investigation, we have synthesized a quinolinium based dual application probe (QnMF) that presents molecular rotor properties. This dual application molecular rotor is able to detect selectively antiparallel G4 sequences (22AG in 100 mM NaCl) through a turn-on response over other G4 topologies. The QnMF also contains a distinct fluorine-19 that undergoes a significant chemical shift in response to microenvironmental changes around the molecule when bound to G4 structures. The probe QnMF exhibits significantly brighter fluorescence emissions in glycerol (ε × ϕ = 2800 cm-1 M-1) and relatively less brighter fluorescence emissions in methanol (ε × ϕ = 40.5 cm-1 M-1). The restricted rotation inherent property of the QnMF molecular rotor is responsible for brighter fluorescence and leads to enhancement in the fluorescence upon binding to the G4 structure. Overall, the probe's dual detection method makes it useful for monitoring the G4 structures that are abundant and plays a vital role in living organisms.
Collapse
Affiliation(s)
- Vardhaman Babagond
- Research Centre, Department of Chemistry, Karnatak University's Karnatak Science College Dharwad, Karnataka, India.
| | - Kariyappa Katagi
- Research Centre, Department of Chemistry, Karnatak University's Karnatak Science College Dharwad, Karnataka, India.
| | - Anup Pandith
- International Ph.D. Program in Biomedical Engineering (IPBME), College of Biomedical Engineering, Taipei Medical University, Taipei City 11031, Taiwan, Republic of China
| | - Mahesh Akki
- Research Centre, Department of Chemistry, Karnatak University's Karnatak Science College Dharwad, Karnataka, India.
| | - Ashwini Jaggal
- Research Centre, Department of Chemistry, Karnatak University's Karnatak Science College Dharwad, Karnataka, India.
| |
Collapse
|
5
|
Johnson RE, Murray MT, Bycraft LJ, Wetmore SD, Manderville RA. A modular aldol approach for internal fluorescent molecular rotor chalcone surrogates for DNA biosensing applications. Chem Sci 2023; 14:4832-4844. [PMID: 37181758 PMCID: PMC10171068 DOI: 10.1039/d3sc00772c] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 04/11/2023] [Indexed: 05/16/2023] Open
Abstract
Fluorescent molecular rotors (FMRs) are critical tools for probing nucleic acid structure and function. Many valuable FMRs have been incorporated into oligonucleotides, although the methods of doing so can be cumbersome. Development of synthetically simple, high yielding modular methods to fine-tune dye performance is crucial to expand the biotechnological applications of oligonucleotides. Herein, we report the utility of 6-hydroxy-indanone (6HI) with a glycol backbone to serve as a handle for on-strand aldehyde capture as a modular aldol approach for site-specific insertion of internal FMR chalcones. Aldol reactions with aromatic aldehydes containing N-donors proceed in high yield to create modified DNA oligonucleotides, which in the duplex match the stability of the fully paired canonical B-form with strong stacking interactions between the planar probe and the flanking base pairs, as evidenced by molecular dynamics (MD) simulations. The FMR chalcones possess remarkable quantum yields (Φfl up to 76%) in duplex DNA, coupled with large Stokes shifts (Δν up to 155 nm), light-up emissions (Irel up to 60-fold) that span the visible region (λem 518-680 nm) with brightness up to 17 480 cm-1 M-1. The library also contains a FRET pair and dual emission probes, suitable for ratiometric sensing. The ease of aldol insertion coupled with the excellent performance of the FMR chalcones permits their future wide-spread use.
Collapse
Affiliation(s)
- Ryan E Johnson
- Department of Chemistry & Toxicology, University of Guelph Guelph Ontario N1G 2W1 Canada
| | - Makay T Murray
- Department of Chemistry & Biochemistry, University of Lethbridge Lethbridge Alberta T1K 3M4 Canada
| | - Lucas J Bycraft
- Department of Chemistry & Toxicology, University of Guelph Guelph Ontario N1G 2W1 Canada
| | - Stacey D Wetmore
- Department of Chemistry & Biochemistry, University of Lethbridge Lethbridge Alberta T1K 3M4 Canada
| | - Richard A Manderville
- Department of Chemistry & Toxicology, University of Guelph Guelph Ontario N1G 2W1 Canada
| |
Collapse
|
6
|
Viviano-Posadas AO, Romero-Mendoza U, Bazany-Rodríguez IJ, Velázquez-Castillo RV, Martínez-Otero D, Bautista-Renedo JM, González-Rivas N, Galindo-Murillo R, Salomón-Flores MK, Dorazco-González A. Efficient fluorescent recognition of ATP/GTP by a water-soluble bisquinolinium pyridine-2,6-dicarboxamide compound. Crystal structures, spectroscopic studies and interaction mode with DNA. RSC Adv 2022; 12:27826-27838. [PMID: 36320280 PMCID: PMC9520314 DOI: 10.1039/d2ra05040d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/21/2022] [Indexed: 11/04/2023] Open
Abstract
The new dicationic pyridine-2,6-dicarboxamide-based compound 1 bearing two N-alkylquinolinium units was synthesized, structurally determined by single-crystal X-ray diffraction, and studied in-depth as a fluorescent receptor for nucleotides and inorganic phosphorylated anions in pure water. The addition of nucleotides to 1 at pH = 7.0 quenches its blue emission with a selective affinity towards adenosine 5'-triphosphate (ATP) and guanosine 5'-tripohosphate (GTP) over other nucleotides such CTP, UTP, ADP, AMP, dicarboxylates and inorganic anions. On the basis of the spectroscopic tools (1H, 31P NMR, UV-vis, fluorescence), MS measurements and DFT calculations, receptor 1 binds ATP with high affinity (log K = 5.04) through the simultaneous formation of strong hydrogen bonds and π-π interactions between the adenosine fragment and quinolinium ring with binding energy calculated in 8.7 kcal mol-1. High affinity for ATP/GTP is attributed to the high acidity of amides and preorganized rigid structure of 1. Receptor 1 is an order of magnitude more selective for ATP than GTP. An efficient photoinduced electron transfer quenching mechanism with simultaneous receptor-ATP complexation in both the excited and ground states is proposed. Additionally, multiple spectroscopic studies and molecular dynamics simulations showed that 1 can intercalate into DNA base pairs.
Collapse
Affiliation(s)
- Alejandro O Viviano-Posadas
- Institute of Chemistry, National Autonomous University of Mexico Circuito Exterior, Ciudad Universitaria México, D.F., 04510 Mexico +52-55-56224514
| | - Ulises Romero-Mendoza
- Institute of Chemistry, National Autonomous University of Mexico Circuito Exterior, Ciudad Universitaria México, D.F., 04510 Mexico +52-55-56224514
| | - Iván J Bazany-Rodríguez
- Institute of Chemistry, National Autonomous University of Mexico Circuito Exterior, Ciudad Universitaria México, D.F., 04510 Mexico +52-55-56224514
| | - Rocío V Velázquez-Castillo
- Institute of Chemistry, National Autonomous University of Mexico Circuito Exterior, Ciudad Universitaria México, D.F., 04510 Mexico +52-55-56224514
| | - Diego Martínez-Otero
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM km 14.5 Carrera Toluca-Atlacomulco, Campus UAEMex "El Rosedal" San Cayetano-Toluca Toluca de Lerdo 50200 Estado de México Mexico
| | - Joanatan M Bautista-Renedo
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM km 14.5 Carrera Toluca-Atlacomulco, Campus UAEMex "El Rosedal" San Cayetano-Toluca Toluca de Lerdo 50200 Estado de México Mexico
| | - Nelly González-Rivas
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM km 14.5 Carrera Toluca-Atlacomulco, Campus UAEMex "El Rosedal" San Cayetano-Toluca Toluca de Lerdo 50200 Estado de México Mexico
| | - Rodrigo Galindo-Murillo
- Department of Medicinal Chemistry, College of Pharmacy, University of Utah 2000 East 30 South Skaggs 306 Salt Lake City 84112 Utah USA
| | - María K Salomón-Flores
- Institute of Chemistry, National Autonomous University of Mexico Circuito Exterior, Ciudad Universitaria México, D.F., 04510 Mexico +52-55-56224514
| | - Alejandro Dorazco-González
- Institute of Chemistry, National Autonomous University of Mexico Circuito Exterior, Ciudad Universitaria México, D.F., 04510 Mexico +52-55-56224514
| |
Collapse
|
7
|
Lu C, Huang PJJ, Zheng J, Liu J. 2-Aminopurine Fluorescence Spectroscopy for Probing a Glucose Binding Aptamer. Chembiochem 2022; 23:e202200127. [PMID: 35468257 DOI: 10.1002/cbic.202200127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/15/2022] [Indexed: 11/05/2022]
Abstract
Glucose is the most important analyte for biosensors. Recently a DNA aptamer was reported allowing binding-based detection. However, due to a relatively weak binding affinity, it is difficult to perform binding assays to understand the property of this aptamer. In this work, we replaced the only adenine base in the aptamer binding pocket with a 2-aminopurine (2AP) and used fluorescence spectroscopy to study glucose binding. In the selection buffer, glucose increased the 2AP fluorescence with a Kd of 15.0 mM glucose, which was comparable with the 10 mM Kd previously reported using the strand displacement assay. The binding required two Na+ ions or one Mg2+ that cannot be replaced by Li+ or K+. The binding was weaker at higher temperature and its van't Hoff plot indicated enthalpy-driven binding. While monosaccharides failed to achieve saturated binding even at high concentrations, two glucose-containing disaccharides, namely trehalose and sucrose, reached a similar fluorescence level as glucose although with over 10-fold higher Kd's. Detection limits in both the selection buffer (0.9 mM) and in artificial interstitial fluids (6.0 mM) were measured.
Collapse
Affiliation(s)
- Chang Lu
- Chinese Academy of Agricultural Sciences, Institute of Food Science and Technology, CHINA
| | | | - Jingkai Zheng
- Chinese Academy of Agricultural Sciences, Institute of Food Science and Technology, CHINA
| | - Juewen Liu
- University of Waterloo, Department of Chemistry, 200 University Avenue West, N2L 3G1, Waterloo, CANADA
| |
Collapse
|
8
|
A fluorescent molecular rotor for the selective detection of the hybrid-conformation 22AG G-Quadruplex. Bioorg Med Chem Lett 2022; 55:128462. [PMID: 34813881 DOI: 10.1016/j.bmcl.2021.128462] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 01/07/2023]
Abstract
G-quadruplex (G4) DNA plays a vital role in myriad biological process and is linked to several human diseases, including Alzheimer's disease. Probing G4s with fluorescent probes can provide a better understanding their mechanisms of action and of their roles in Nature. In this study we developed a quinolinium-vinylaniline molecular rotor probe, featuring a diethylaminosalicylaldehyde unit that could discriminate the hybrid-22AG G4 sequence selectively amongst other G4 sequences. This probe underwent a significant red-shift upon binding to the target G4 (broad 575 nm → sharp 630 nm) with enhanced fluorescence (up to 14-fold). We suspect that the vinylaniline unit of the molecular rotor, when bound to the hybrid-22 A G4, experienced restricted rotation, thereby undergoing enhanced intramolecular charge transfer. The presence of the diethylaminosalicylaldehyde moiety appeared to play a major role in the enhanced selectivity toward the 22AG G4.
Collapse
|
9
|
Johnson RE, Van Riesen AJ, Manderville RA. On-Strand Knoevenagel Insertion of a Hemicyanine Molecular Rotor Loop Residue for Turn-On Fluorescence Detection of Pb-Induced G-Quadruplex Rigidity. Bioconjug Chem 2021; 32:2224-2232. [PMID: 34543022 DOI: 10.1021/acs.bioconjchem.1c00386] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We demonstrate the ability to distinguish Pb2+ from K+ within the central cavity of the antiparallel G-quadruplex (GQ) DNA produced by the thrombin binding aptamer (TBA) using an internal molecular rotor fluorescent probe. An indole-aldehyde containing an acyclic N-glycol group was first employed in the on-strand Knoevenagel condensation with five different heterocyclic quaternary cationic acceptors to assess the molecular rotor character of the resulting cyanine-styryl dyes within duplex DNA. An indole-pyridinium (4PI) nucleobase surrogate displayed the greatest turn-on emission response to duplex formation and was thus inserted into the loop residues of TBA to monitor GQ-folding in the presence of Pb2+ versus K+. TBA-4PI exhibits turn-on emission upon Pb2+-binding with a brightness (ε·Φfl) of 9000 cm-1 M-1 compared to K+-binding (ε·Φfl ∼ 2000 cm-1 M-1) due to Pb2+-induced GQ rigidity with 4PI-G-tetrad stacking interactions. The Pb2+-bound TBA-4PI GQ also provides energy-transfer (ET) fluorescence with a diagnostic excitation at 310 nm for distinguishing Pb2+ from K+ within the antiparallel GQ. The TBA-4PI GQ affords the desired turn-on fluorescence response for detecting Pb2+ ions with an apparent dissociation constant (Kd) of 63 nM and a limit of detection (LOD) of 19 nM in an aqueous buffer. It can also distinguish Pb2+ (230 nM) from K+ (1.5 mM, 6500-fold excess) in an antiparallel GQ recognition motif without topology twitching.
Collapse
Affiliation(s)
- Ryan E Johnson
- Departments of Chemistry and Toxicology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Abigail J Van Riesen
- Departments of Chemistry and Toxicology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Richard A Manderville
- Departments of Chemistry and Toxicology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| |
Collapse
|
10
|
Electrochemical aptasensor based on proximity binding-induced DNA networked for enzyme-free and ultrasensitive detection of thrombin. J Electroanal Chem (Lausanne) 2021. [DOI: 10.1016/j.jelechem.2021.115447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
11
|
Manning TW, Van Riesen AJ, Manderville RA. Screening Internal Donor-Acceptor Biaryl Nucleobase Surrogates for Turn-On Fluorescence Affords an Aniline-Carboxythiophene Probe for Protein Detection by G-Quadruplex DNA. Bioconjug Chem 2021; 32:1791-1801. [PMID: 34138558 DOI: 10.1021/acs.bioconjchem.1c00270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Donor-acceptor biaryls serve as microenvironment fluorescent sensors with highly quenched intramolecular charge transfer (ICT) emission in polar protic solvents that turns on in aprotic media. In DNA, canonical donor-acceptor fluorescent base analogs can be prepared through on-strand Suzuki-Miyaura cross-coupling reactions involving 8-bromo-2'-deoxyguanosine (8-Br-dG) with an acceptor aryboronic acid. Herein, we demonstrate that replacement of 8-Br-dG with N-methyl-4-bromoaniline (4-Br-An) containing an acyclic N-glycol group can be employed in the on-strand Suzuki-Miyaura reaction to afford new donor-acceptor biaryl nucleobase surrogates with a 40-fold increase in emission intensity for fluorescent readout within single-strand oligonucleotides. Screening the best acceptor for turn-on fluorescence upon duplex formation afforded the carboxythiophene derivative [COOTh]An with a 7.4-fold emission intensity increase upon formation of a single-bulged duplex (-1) with the surrogate occupying a pyrimidine-flanked bulge. Insertion of the [COOTh]An surrogate into the lateral TT loops produced by the antiparallel G-quadruplex (GQ) of the thrombin binding aptamer (TBA) afforded a 4.1-fold increase in probe fluorescence that was accompanied by a 20 nm wavelength shift to the blue upon thrombin binding. The modified TBA afforded a limit of detection of 129 nM for thrombin and displayed virtually no emission response to off-target proteins. The fluorescence response of [COOTh]An to thrombin binding highlights the utility of the thienyl-aniline moiety for monitoring DNA-protein interactions.
Collapse
Affiliation(s)
- Trevor W Manning
- Departments of Chemistry and Toxicology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Abigail J Van Riesen
- Departments of Chemistry and Toxicology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Richard A Manderville
- Departments of Chemistry and Toxicology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| |
Collapse
|