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Zhang J, Zhang L, Zhou Y, Li K, Dai X, Bian L. The fluorescence regulation of a tri-functional oligonucleotide probe HEX-OND in detecting Pb(II), cysteine, and K(I) based on two G-quadruplex forms. Anal Bioanal Chem 2023; 415:2763-2774. [PMID: 37103561 DOI: 10.1007/s00216-023-04681-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/27/2023] [Accepted: 03/31/2023] [Indexed: 04/28/2023]
Abstract
A novel tri-functional probe HEX-OND was developed for detecting Pb(II), cysteine (Cys), and K(I) by fluorescence quenching, recovery, and amplification strategies respectively, based on Pb(II)-induced chair-type G-quadruplex (CGQ) and K(I)-induced parallel G-quadruplex (PGQ). The thermodynamic mechanism was illustrated as that HEX-OND transformed into CGQ by associating equimolar Pb(II) (K1 = 1.10 ± 0.25 × 106 L/mol), forcing (G)2 spontaneously approaching and static-quenching HEX (5'-hexachlorofluorescein phosphoramidite) in the photo-induced electron transfer (PET) way by the van der Waals force and hydrogen bond (K2 = 5.14 ± 1.65 × 107 L/mol); the additional Cys recovered fluorescence in the molecular ratio of 2:1 via Pb(II)-precipitation induced CGQ destruction (K3 = 3.03 ± 0.77 × 109 L/mol); the equimolar K(I) induced HEX-OND transforming into PGQ (K4 = 3.53 ± 0.30 × 104 L/mol) and specifically associating with the equimolar N-methyl mesoporphyrin IX (NMM) by hydrophobic force (K5 = 3.48 ± 1.08 × 105 L/mol), leading to the fluorescence enhancement. Moreover, the practicability results showed that the detection limits reached a nanomolar level for Pb(II) and Cys and micromolar for K(I), with mere disturbances for 6, 10, and 5 kinds of other substances, respectively; no significant deviations of the real sample detection results were found between the well-understood methods with ours in detecting Pb(II) and Cys, and K(I) could be recognized and quantified even in the presence of Na(I) with 5000 and 600 fold respectively. The results demonstrated the triple-function, sensitivity, selectivity, and tremendous application feasibility of the current probe in sensing Pb(II), Cys, and K(I).
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Affiliation(s)
- Jiaxin Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Ling Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Yaqi Zhou
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Kewei Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Xufen Dai
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Liujiao Bian
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, China.
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Gu P, Lu Y, Li S, Ma C. A Label-Free Fluorescence Aptasensor Based on G-Quadruplex/Thioflavin T Complex for the Detection of Trypsin. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27186093. [PMID: 36144829 PMCID: PMC9503660 DOI: 10.3390/molecules27186093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/16/2022] [Accepted: 09/16/2022] [Indexed: 11/30/2022]
Abstract
A novel, label-free fluorescent assay has been developed for the detection of trypsin by using thioflavin T as a fluorescent probe. A specific DNA aptamer can be combined by adding cytochrome c. Trypsin hydrolyzes the cytochrome c into small peptide fragments, exposing the G-quadruplex part of DNA aptamer, which has a high affinity for thioflavin T, which then enhances the fluorescence intensity. In the absence of trypsin, the fluorescence intensity was inhibited as the combination of cytochrome c and the DNA aptamer impeded thioflavin T’s binding. Thus, the fluorescent biosensor showed a linear relationship from 0.2 to 60 μg/mL with a detection limit of 0.2 μg/mL. Furthermore, the proposed method was also successfully employed for determining trypsin in biological samples. This method is simple, rapid, cheap, and selective and possesses great potential for the detection of trypsin in bioanalytical and biological samples and medical diagnoses.
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Park J, Han H, Park C, Ahn JK. Washing-Free and Label-Free Onsite Assay for Inorganic Pyrophosphatase Activity Using a Personal Glucose Meter. Anal Chem 2022; 94:11508-11513. [PMID: 35968937 DOI: 10.1021/acs.analchem.2c01412] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we demonstrated a personal glucose meter-based method for washing-free and label-free inorganic pyrophosphatase (PPase) detection, which relies on the cascade enzymatic reaction (CER) promoted by hexokinase and pyruvate kinase. In principle, the absence of target PPase enables adenosine triphosphate sulfurylase to catalyze the conversion of pyrophosphate (PPi) to ATP, a substrate of CER, which results in the significant reduction of glucose levels by the effective CER process. In contrast, the PPi cleavage activity works in the presence of target PPase by decomposing PPi to orthophosphate (Pi). Therefore, the CER process cannot be effectively executed, leading to the maintenance of the initial high glucose level that may be measured by a portable personal glucose meter. Based on this novel strategy, a quantitative evaluation of the PPase activity may be achieved in a dynamic linear range of 1.5-25 mU/mL with a detection limit of 1.18 mU/mL. Compared with the previous PPase detection methods, this method eliminates the demand for expensive and bulky analysis equipment as well as a complex washing step. More importantly, the diagnostic capability of this method was also successfully verified by reliably detecting PPase present in an undiluted human serum sample with an excellent recovery ratio of 100 ± 2%.
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Affiliation(s)
- Junhyun Park
- Material & Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Korea.,Department of Biological Engineering, College of Engineering, Konkuk University, Seoul 05029, Korea
| | - Hyogu Han
- Material & Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Korea.,Department of Chemistry, Gangneung-Wonju National University, Gangneung 25457, Korea
| | - Chihyun Park
- Daejeon District Office, National Forensic Service, Daejeon 34054, Korea
| | - Jun Ki Ahn
- Material & Component Convergence R&D Department, Korea Institute of Industrial Technology (KITECH), Ansan 15588, Korea
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Label-Free miRNA-21 Analysis Based on Strand Displacement and Terminal Deoxynucleotidyl Transferase-Assisted Amplification Strategy. BIOSENSORS 2022; 12:bios12050328. [PMID: 35624629 PMCID: PMC9138311 DOI: 10.3390/bios12050328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 04/26/2022] [Accepted: 05/10/2022] [Indexed: 12/02/2022]
Abstract
MicroRNAs (miRNAs) are regarded as a rising star in the biomedical industry. By monitoring slight increases in miRNA-21 levels, the possibilities of multi-type malignancy can be evaluated more precisely and earlier. However, the inconvenience and insensitivity of traditional methods for detecting miRNA-21 levels remains challenging. In this study, a partially complementary cDNA probe was designed to detect miRNA-21 with target-triggered dual amplification based on strand displacement amplification (SDA) and terminal deoxynucleotidyl transferase (TdT)-assisted amplification. In this system, the presence of miRNA-21 can hybridize with template DNA to initiate SDA, generating a large number of trigger molecules. With the assistance of TdT and dGTP, the released trigger DNA with 3′-OH terminal can be elongated to a superlong poly(guanine) sequence, and a notable fluorescence signal was observed in the presence of thioflavin T. By means of dual amplification strategy, the sensing platform showed a good response tomiRNA-21 with a detection limit of 1.7 pM (S/N = 3). Moreover, the specificity of this method was verified using a set of miRNA with sequence homologous to miRNA-21. In order to further explore its practical application capabilities, the expression of miRNA in different cell lines was quantitatively analyzed and compared with the qRT-PCR. The considerable results of this study suggest great potential for the application of the proposed approach in clinical diagnosis.
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A Novel Colorimetric Nano Aptasensor for Ultrasensitive Detection of Aflatoxin B1 Based on the Exonuclease III-Assisted Signal Amplification Approach. Foods 2021; 10:foods10112568. [PMID: 34828849 PMCID: PMC8625208 DOI: 10.3390/foods10112568] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/15/2021] [Accepted: 10/16/2021] [Indexed: 12/25/2022] Open
Abstract
The detection of aflatoxin B1 (AFB1) has recently garnered much attention on the issue of food safety. In this study, a novel and sensitive aptasensor towards AFB1 is proposed using an Exonuclease III (Exo III)-integrated signal amplification strategy. This reported sensing strategy is regulated by aptamer-functionalized nanobeads that can target AFB1; furthermore, complementary DNA (cDNA) strands can lock the immobilized aptamer strands, preventing the signal amplification function of Exo III in the absence of AFB1. The presence of AFB1 triggers the displacement of cDNA, which will then activate the Exo III-integrated signal amplification procedure, resulting in the generation of a guanine (G)-rich sequence to form a G-4/hemin DNAzyme, which can catalyze the substrate of ABTS to produce a green color. Using this method, a practical detection limit of 0.0032 ng/mL and a dynamic range of detection from 0.0032 to 50 ng/mL were obtained. Additionally, the practical application of the established sensing method for AFB1 in complex matrices was demonstrated through recovery experiments. The recovery rate and relative standard deviations (RSD) in three kinds of cereal samples ranged from 93.83% to 111.58%, and 0.82% to 7.20%, respectively, which were comparable with or better than previously reported methods.
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Vinod SP, Vignesh R, Priyanka M, Tirumurugaan KG, Sivaselvam SN, Raj GD. Generation of single stranded DNA with selective affinity to bovine spermatozoa. Anim Biosci 2021; 34:1579-1589. [PMID: 32882770 PMCID: PMC8495356 DOI: 10.5713/ajas.20.0235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/11/2020] [Accepted: 07/23/2020] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE This study was conducted to generate single stranded DNA oligonucleotides with selective affinity to bovine spermatozoa, assess its binding potential and explore its potential utility in trapping spermatozoa from suspensions. METHODS A combinatorial library of 94 mer long oligonucleotide was used for systematic evolution of ligands by exponential enrichment (SELEX) with bovine spermatozoa. The amplicons from sixth and seventh rounds of SELEX were sequenced, and the reads were clustered employing cluster database at high identity with tolerance (CD-HIT) and FASTAptamer. The enriched nucleotides were predicted for secondary structures by Mfold, motifs by Multiple Em for Motif Elicitation and 5' labelled with biotin/6-FAM to determine the binding potential and binding pattern. RESULTS We generated 14.1 and 17.7 million reads from sixth and seventh rounds of SELEX respectively to bovine spermatozoa. The CD-HIT clustered 78,098 and 21,196 reads in the top ten clusters and FASTAptamer identified 2,195 and 4,405 unique sequences in the top three clusters from the sixth and seventh rounds, respectively. The identified oligonucleotides formed secondary structures with delta G values between -1.17 to -26.18 kcal/mol indicating varied stability. Confocal imaging with the oligonucleotides from the seventh round revealed different patterns of binding to bovine spermatozoa (fluorescence of the whole head, spot of fluorescence in head and mid- piece and tail). Use of a 5'-biotin tagged oligonucleotide from the sixth round at 100 pmol with 4×106 spermatozoa could trap almost 80% from the suspension. CONCLUSION The binding patterns and ability of the identified oligonucleotides confirms successful optimization of the SELEX process and generation of aptamers to bovine spermatozoa. These oligonucleotides provide a quick approach for selective capture of spermatozoa from complex samples. Future SELEX rounds with X- or Y- enriched sperm suspension will be used to generate oligonucleotides that bind to spermatozoa of a specific sex type.
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Affiliation(s)
- Sivadasan Pathiyil Vinod
- Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai – 600051, India
| | - Rajamani Vignesh
- Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai – 600051, India
| | - Mani Priyanka
- Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai – 600051, India
| | - Krishnaswamy Gopalan Tirumurugaan
- Department of Animal Biotechnology, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai – 600051, India
| | - Salem Nagalingam Sivaselvam
- Department of Animal Genetics and Breeding, Madras Veterinary College, Tamil Nadu Veterinary and Animal Sciences University, Chennai – 600051, India
| | - Gopal Dhinakar Raj
- Centre for Animal Health Studies, Tamil Nadu Veterinary and Animal Sciences University, Chennai – 600051, India
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Olejnik B, Kozioł A, Brzozowska E, Ferens-Sieczkowska M. Application of selected biosensor techniques in clinical diagnostics. Expert Rev Mol Diagn 2021; 21:925-937. [PMID: 34289786 DOI: 10.1080/14737159.2021.1957833] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Examination of disease biomarkers mostly performed on crude materials, such as serum, meets some obstacles, resulting from sample complexity and the wide range of concentrations and sizes of the components. Techniques currently used in clinical diagnostics are usually time-consuming and expensive. The more sensitive and portable devices are needed for early diagnostics. Chemical sensors are devices that convert chemical information into parameters suitable for fast and precise processing and measurement. AREA COVERED We review the use of biosensors and their possible application in early diagnostics of some diseases like cancer or viral infections. We focus on different types of biorecognition and some technical modifications, lowering the limit of detection potentially attractive to medical practitioners. EXPERT OPINION Among the new diagnostic strategies, the use of biosensors is of increasing interest. In these techniques, the capture ligand interacts with the analyte of interest. Measuring interactions between partners in real time by surface plasmon resonance yields valuable information about kinetics and affinity in a short time and without labels. Importantly, the tendency in such techniques is to make biosensor devices smaller and the test results apparent with the naked eye, so they can be used in point-of-care medicine.
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Affiliation(s)
- Beata Olejnik
- Department of Chemistry and Immunochemistry, Medical University of Wroclaw, Wrocław, Poland
| | - Agata Kozioł
- Department of Chemistry and Immunochemistry, Medical University of Wroclaw, Wrocław, Poland
| | - Ewa Brzozowska
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Laboratory of Medical Microbiology, Wrocław, Poland
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Xu J, Jiang R, He H, Ma C, Tang Z. Recent advances on G-quadruplex for biosensing, bioimaging and cancer therapy. Trends Analyt Chem 2021. [DOI: 10.1016/j.trac.2021.116257] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Cruz A, Núñez-Montenegro A, Mateus P, Delgado R. Monitoring inorganic pyrophosphatase activity with the fluorescent dizinc(ii) complex of a macrocycle bearing one dansylamidoethyl antenna. Dalton Trans 2020; 49:9487-9494. [PMID: 32608414 DOI: 10.1039/d0dt01673j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The dizinc(ii) complexes of L were used for the recognition of anions by fluorescence spectroscopy (L is a heteroditopic hexaazamacrocycle with two diethylenetriamine coordination heads with 2-methylpyridyl and dansylamido ethyl arms, and m-xylyl spacers). The protonation of L and stability constants of its zinc(ii) complexes were determined in aqueous solution, at 298.2 ± 0.1 K and I = 0.10 ± 0.01 M in KNO3. At a 2 : 1 Zn2+/L ratio, the dinuclear complexes clearly dominate. The ligand alone does not display fluorescence changes upon increasing the pH value, but in the presence of Zn2+ the emission reaches a maximum at pH ≅ 7.5, at which 95% of the ligand is in the dinuclear complex form. The emission appears concomitantly with the [Zn2H-1L]3+ species formation, which supports that the latter complex corresponds to the metal-promoted deprotonation of dansylamide NH. The [Zn2H-1L]3+ complexes were used for the recognition of phosphate and polyphosphate anions in aqueous solution buffered at pH 7.5 with 2 mM PIPPS, at 298.2 K. The binding of anions causes a decrease of the emission. The association constant determination revealed that HPPi3- is the strongest bound anion (log Kapp = 5.57), followed by HATP3- (two times weaker), and the remaining anions show lower binding constants, with HPO42- having the weakest uptake by the receptor. The observed selectivity of the [Zn2H-1L]3+ receptor for PPi in relation to HPO42-, and the fact that the formation of the [Zn2H-1L]3+ complex is not disturbed by the presence of Mg2+, allowed monitoring of the PPi hydrolysis by using inorganic pyrophosphatase in real-time.
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Affiliation(s)
- Ana Cruz
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
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Odeh F, Nsairat H, Alshaer W, Ismail MA, Esawi E, Qaqish B, Bawab AA, Ismail SI. Aptamers Chemistry: Chemical Modifications and Conjugation Strategies. Molecules 2019; 25:E3. [PMID: 31861277 PMCID: PMC6982925 DOI: 10.3390/molecules25010003] [Citation(s) in RCA: 173] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 12/14/2019] [Accepted: 12/17/2019] [Indexed: 12/21/2022] Open
Abstract
Soon after they were first described in 1990, aptamers were largely recognized as a new class of biological ligands that can rival antibodies in various analytical, diagnostic, and therapeutic applications. Aptamers are short single-stranded RNA or DNA oligonucleotides capable of folding into complex 3D structures, enabling them to bind to a large variety of targets ranging from small ions to an entire organism. Their high binding specificity and affinity make them comparable to antibodies, but they are superior regarding a longer shelf life, simple production and chemical modification, in addition to low toxicity and immunogenicity. In the past three decades, aptamers have been used in a plethora of therapeutics and drug delivery systems that involve innovative delivery mechanisms and carrying various types of drug cargos. However, the successful translation of aptamer research from bench to bedside has been challenged by several limitations that slow down the realization of promising aptamer applications as therapeutics at the clinical level. The main limitations include the susceptibility to degradation by nucleases, fast renal clearance, low thermal stability, and the limited functional group diversity. The solution to overcome such limitations lies in the chemistry of aptamers. The current review will focus on the recent arts of aptamer chemistry that have been evolved to refine the pharmacological properties of aptamers. Moreover, this review will analyze the advantages and disadvantages of such chemical modifications and how they impact the pharmacological properties of aptamers. Finally, this review will summarize the conjugation strategies of aptamers to nanocarriers for developing targeted drug delivery systems.
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Affiliation(s)
- Fadwa Odeh
- Faculty of Science, The University of Jordan, Amman 11942, Jordan; (F.O.); (H.N.); (A.A.B.)
- Hamdi Mango Center for Scientific Research, The University of Jordan, Amman 11942, Jordan
| | - Hamdi Nsairat
- Faculty of Science, The University of Jordan, Amman 11942, Jordan; (F.O.); (H.N.); (A.A.B.)
| | - Walhan Alshaer
- Cell Therapy Center, The University of Jordan, Amman 11942, Jordan
| | - Mohammad A. Ismail
- Faculty of Medicine, The University of Jordan, Amman 11942, Jordan; (M.A.I.); (E.E.); (B.Q.); (S.I.I.)
| | - Ezaldeen Esawi
- Faculty of Medicine, The University of Jordan, Amman 11942, Jordan; (M.A.I.); (E.E.); (B.Q.); (S.I.I.)
| | - Baraa Qaqish
- Faculty of Medicine, The University of Jordan, Amman 11942, Jordan; (M.A.I.); (E.E.); (B.Q.); (S.I.I.)
| | - Abeer Al Bawab
- Faculty of Science, The University of Jordan, Amman 11942, Jordan; (F.O.); (H.N.); (A.A.B.)
- Hamdi Mango Center for Scientific Research, The University of Jordan, Amman 11942, Jordan
| | - Said I. Ismail
- Faculty of Medicine, The University of Jordan, Amman 11942, Jordan; (M.A.I.); (E.E.); (B.Q.); (S.I.I.)
- Qatar Genome Project, Qatar Foundation, Doha 5825, Qatar
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Roxo C, Kotkowiak W, Pasternak A. G-Quadruplex-Forming Aptamers-Characteristics, Applications, and Perspectives. Molecules 2019; 24:E3781. [PMID: 31640176 PMCID: PMC6832456 DOI: 10.3390/molecules24203781] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/16/2019] [Accepted: 10/18/2019] [Indexed: 12/31/2022] Open
Abstract
G-quadruplexes constitute a unique class of nucleic acid structures formed by G-rich oligonucleotides of DNA- or RNA-type. Depending on their chemical nature, loops length, and localization in the sequence or structure molecularity, G-quadruplexes are highly polymorphic structures showing various folding topologies. They may be formed in the human genome where they are believed to play a pivotal role in the regulation of multiple biological processes such as replication, transcription, and translation. Thus, natural G-quadruplex structures became prospective targets for disease treatment. The fast development of systematic evolution of ligands by exponential enrichment (SELEX) technologies provided a number of G-rich aptamers revealing the potential of G-quadruplex structures as a promising molecular tool targeted toward various biologically important ligands. Because of their high stability, increased cellular uptake, ease of chemical modification, minor production costs, and convenient storage, G-rich aptamers became interesting therapeutic and diagnostic alternatives to antibodies. In this review, we describe the recent advances in the development of G-quadruplex based aptamers by focusing on the therapeutic and diagnostic potential of this exceptional class of nucleic acid structures.
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Affiliation(s)
- Carolina Roxo
- Department of Nucleic Acids Bioengineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
| | - Weronika Kotkowiak
- Department of Nucleic Acids Bioengineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
| | - Anna Pasternak
- Department of Nucleic Acids Bioengineering, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
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A label-free fluorescence method based on terminal deoxynucleotidyl transferase and thioflavin T for detecting prostate-specific antigen. Anal Bioanal Chem 2019; 411:5779-5784. [DOI: 10.1007/s00216-019-01958-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/27/2019] [Accepted: 06/03/2019] [Indexed: 10/26/2022]
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Wang H, Ma C, Li Z, Wu K. An exonuclease-assisted fluorescence sensor for assaying alkaline phosphatase based on SYBR Green I. Mol Cell Probes 2019; 45:26-30. [PMID: 30981621 DOI: 10.1016/j.mcp.2019.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/08/2019] [Accepted: 04/08/2019] [Indexed: 01/27/2023]
Abstract
In this report, we propose a fast, reliable and convenient approach to determine the alkaline phosphatase (ALP) activity based on a label-free fluorescence strategy. Upon catalysis of ALP, dephosphorylated dsDNA hampers the λ exonuclease (λexo) cleavage, shows high affinity to SYBR Green I (SG I), resulting in a strong fluorescence emission peak at 520 nm. In the absence of ALP, the dsDNA with 5'-phosphoryl-termini could be employed as a substrate of λexo. After cleavage, a weak fluorescence emission peaks at 520 nm could be observed. The assay was both selective and sensitive, and the detection limit was found to be as low as 3 U/L. This method was utilized to evaluate Na3VO4 as ALP inhibitor. The method was successfully applied to the determination of the activity of ALP in spiked human serum samples.
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Affiliation(s)
- Huiyu Wang
- School of Life Sciences, Central South University, Changsha, 410013, China; XiangYa School of Medicine, Central South University, Changsha, 410013, China
| | - Changbei Ma
- School of Life Sciences, Central South University, Changsha, 410013, China.
| | - Zekun Li
- School of Life Sciences, Central South University, Changsha, 410013, China; XiangYa School of Medicine, Central South University, Changsha, 410013, China
| | - Kefeng Wu
- School of Life Sciences, Central South University, Changsha, 410013, China
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