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1.
Analyst ; 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31820746

RESUMO

Owing to its high sensitivity, a solution-gated graphene transistor has rapidly emerged as a cutting edge technology in electrochemical sensing. In this work, composites of gold nanoparticles and reduced graphene oxide were synthesized on a glassy carbon electrode by using the electrodeposition method. A modified glassy carbon electrode was used as the gate electrode and assembled into the solution-gated graphene transistor device along with the graphene channel for a non-invasive glucose detection. The sensing mechanism was based on the change in current in the channel of the device caused by the addition of glucose, of which electro-oxidation on the surface of the gold nanoparticles and reduced graphene oxide led to a change in equivalent gate voltage, and consequently, affected the channel carrier concentration. The self-amplification effect of transistors was utilized in our sensors, which resulted in a detection limit that was 10 times lower than those of conventional electrochemical sensors. Compared to traditional enzymatic transistor sensors, the novel solution-gated graphene transistor nonenzymatic sensors based on gold nanoparticles and reduced graphene oxide demonstrated significant sensing advantages, such as a simple structure, wide linear range from 10 µM to 400 µM and 400 µM to 31 mM, and low detection limit down to 4 µM. The chemicals coexisting in human sweat e.g. sodium chloride, urea, and lactic acid imposed no distinct interference for the glucose detection. Therefore, we achieved a non-invasive detection of glucose in the artificial sweat samples with satisfactory sensing results. This work demonstrates an effective route for non-invasive glucose testing in practical clinical diagnosis by using nonenzymatic, solution-gated graphene transistor devices.

2.
Biosens Bioelectron ; 146: 111751, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31605988

RESUMO

Detection of nitrite is important for environmental safety and human health, and the development of high-performance sensors for accurate detection of nitrite is highly desirable. Herein, a highly sensitive graphene electrochemical transistor (GECT) nitrite sensor was designed and fabricated for the first time. A single layer of graphene was placed between the source and drain electrodes by the wetting transfer method to act as channel for the transistor. Au nanoparticles modified reduced graphene oxide nanocomposites (AuNPs/RGO) were electrodeposited at the transistor gate to improve its catalytic oxidation performance of nitrite with optimized electrodeposition conditions. The sensing principle was attributed to changes in effective gate voltage applied to GECT induced by electrooxidation of nitrite at gate electrodes. Due to the high carrier mobility of graphene in the channel and the excellent electrocatalytical activity of AuNPs/RGO on the gate, the obtained sensor device exhibited an exceedingly low detection limit (0.1 nM nitrite) and ultra-wide linear range from 0.1 nM to 7 µM and from 7 to 1000 µM, which are comparable or superior to the performance of large-scale instruments (e.g. chromatography, spectrophotometry, and spectrofluorimetry etc.). The GECT device also showed good anti-interference performance toward common interfering ions and stable performances. Nitrite in natural lake water has been proven to be monitored by our devices. Therefore, the present novel GECT sensor could act as a desirable practical platform for highly sensitive detection of nitrite in the food and environmental fields.

3.
Mikrochim Acta ; 186(11): 722, 2019 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-31655901

RESUMO

A nanocomposite was prepared from gold and graphene oxide via one-step electrodeposition and used to modify the surface of a gold electrode (Au-Gr/GE) that was then applied to non-enzymatic determination of glucose. The effects of deposition time and supporting substrate on the morphology, structure, and electrochemical properties of the nanocomposite were optimized. The morphologies and crystal structures were characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The results indicate that gold nanoparticles grew on the surface of two-dimensional graphene oxide. The electrocatalytic activity of the modified electrode towards glucose oxidation was evaluated by cyclic voltammetry and amperometric methods at pH 7.4. The Au-Gr/GE, typically operated at a potential of 0.00 V (vs. Ag/AgCl), has a linear response in the 0.05-14 mM and 14-42 mM glucose concentration range, high sensitivity (604 and 267 µA cm-2 mM-1) and a low detection limit (12 µM). The modified GE was applied to quantify glucose in sweat where it exhibited excellent sensitivity and accuracy. Graphical abstract The gold electrode modified with a gold-graphene (Au-Gr/GE) is prepared via a direct electrodeposition. The Au-Gr/GE is used for glucose detection in the neutral solution and it can achieve the effect of non-intrusive detection.

4.
Biosens Bioelectron ; 142: 111537, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31376709

RESUMO

Electrochemical detection of specific nucleic acid sequence remains a hot topic in current bioanalytical research. Here, a novel ratiometric electrochemical biosensor based on Exo III-assisted recycling amplification and graphene-modified electrode was fabricated for quantitative detection of trinucleotide repeat sequence d(CAG)n. The double-signals used are the hairpin DNAs labeled with ferrocene and methylene blue respectively as report DNAs, which can hybridize to target DNA. The hybridized DNA was digested by Exo III, resulting in the release of target and report fragments. The graphene-modified electrode can selectively adsorb the released report fragments to generate double electrochemical signals. The signal ratio (F/M) of ferrocene and methylene blue was used to determine the repeat length accurately: a linear relationship was found between F/M and numbers of repeats (n), F/M = 0.061 n + 1.97, with a correlation coefficient of 0.992. Moreover, any electrochemical signal can be used to test repeat concentration with detection limit of 0.22 pM. Therefore, this novel ratiometric electrochemical biosensor provided a reliable and efficient method for the analysis of d(CAG)n trinucleotide repeat and a potential simplified clinical tool for neurodegenerative diseases.

5.
Biosens Bioelectron ; 118: 174-180, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30077131

RESUMO

In the paper, a triple-amplified biosensor was built for the purpose of ultrasensitive methyltransferase (Dam MTase) activity detection and inhibitor screening based on in-situ synthesized silver nanoclusters (AgNCs) as signal probes to provide amplified current signal coupling with gold nanoparticles/electrochemical reduced graphene oxide (AuNPs/ERGO) hybrids and hybridization chain reactions (HCR) amplification strategy. For biosensor preparation, the AuNPs/ERGO hybrids were firstly generated on the electrode surface by electrochemical co-reduction method, then the ds-DNA structures which comprised the specific recognition sequences (5'-G-A-T-C-3') of the Dam MTase and the restrictive endonuclease DpnI were formed on the electrode by the hybridization of the assistant DNA with the capture DNA. The presence of Dam MTase methylated partial ds-DNA structures on the electrode which could be digested by DpnI and could not undergo HCR process. The unmethylated ds-DNA structures underwent HCR process to further hybridize with DNA1 and DNA2 to form ds-DNA superstructures as effective template for AgNCs in-situ synthesis. Oxidation peak current of silver was obtained as signal output for Dam MTase detection. Integrated synthesis and detection in one as well as combined metal nanocluster with DNA superstructures, this biosensor showed a good performance for Dam MTase activity detection with a detection limit of 0.0073 U/mL. Compared with reported biosensor, the designed biosensor showed high sensitivity and had potential in clinical diagnosis as well as inhibitor screening.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas , Nanopartículas Metálicas/química , Metiltransferases/metabolismo , Técnicas Biossensoriais/instrumentação , Ouro/química , Prata/química
6.
ACS Appl Mater Interfaces ; 9(50): 44231-44240, 2017 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-29155546

RESUMO

Electrochemical sensors now play an important role in analysis and detection of nucleic acids. In this work, we present a novel double-signal technique for electrochemically measuring the sequence and length of the d(CAG)n repeat. The double-signal technique used an electrochemical molecular beacon (a hairpin DNA labeled with ferrocene), which was directly modified on the surface of a gold electrode, while a reporter probe (a DNA sequence labeled with horseradish peroxidase) was hybridized to the target DNA. First a simple single-signal sensor was characterized in which d(CAG)n repeats were detected using a short reporter DNA strand labeled with horseradish peroxidase. To obtain a reliable signal that was dependent on repeat number, a double-signal biosensor was created in which the single strand capture DNA in single-signal sensor was replaced by an electrochemical molecular beacon labeled with ferrocene. When the hairpin DNA hybridized to the target-reporter DNA complex, it opened, resulting in a decreased ferrocene current. Both electrochemical biosensors exhibited high selectivity and sensitivity with low detection limits of 0.21 and 0.15 pM, respectively, for the detection of d(CAG)n repeats. The double-signal sensor was more accurate for the determination of repeat length, which was measured from the ratio of signals for HRP and ferrocene (H/F). A linear relationship was found between H/F and the number of repeats (n), H/F = 0.1398n + 9.89788, with a correlation coefficient of 0.974. Only 10 nM of target DNA was required for measurements based on the value of H/F in the double-signal technique. These results indicated that this new double-signal electrochemical sensor provided a reliable method for the analysis of CAG trinucleotide repeats.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Eletrodos , Ouro , Repetições de Trinucleotídeos
7.
Anal Sci ; 33(5): 585-590, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28496062

RESUMO

In this paper, a novel electrochemical sensor was developed for the rapid detection of G-G mismatched DNA based on hexaammineruthenium(III) chloride ([Ru(NH3)6]Cl3) as a redox indicator. The sensor platform was constructed by immobilizing small molecules (NC-linker) on the gold electrode via amide bonds. The as-prepared NC-linker as the nucleic acids recognition molecule can interact with the G base of DNA. After the sensor was incubated with G-G mismatched DNA, the double-stranded DNA (dsDNA) acted as carriers of the signal tags-[Ru(NH3)6]Cl3, which resulted in a remarkable electrochemical signal. More binding of [Ru(NH3)6]Cl3 led to increases of the electrochemical signal. Other mismatched DNA produced only a low response, as well as complementary DNA. Thus G-G mismatched DNA can be easily discriminated from other mismatched and complementary DNA based on the sensor. Furthermore, the method was simple, rapid and repeatable for the detection of G-G mismatched DNA. The selective detection of target dsDNA was achieved by a relative current ratio of the target and control DNA. These results demonstrated that this strategy could provide great promise for the rapid and specific detection of other sequence-specific DNA.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/análise , Técnicas Eletroquímicas/métodos , Compostos de Rutênio/química , Pareamento Incorreto de Bases , DNA de Cadeia Simples/genética , Oxirredução
8.
J Fluoresc ; 27(4): 1405-1411, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28391542

RESUMO

In this paper, a new type of ratiometric fluorescent probe HBT-TCF with large emission shift (up to 200 nm) has been developed for sensing HSO3- based on Michael-type addition reaction. The probe could fast recognize of HSO3- within 3 min in PBS buffer solution. The detection limit of the probe for HSO3- is as low as 101 nM. Meanwhile, the sensing mechanism is confirmed by NMR, LCMS. In addition, the probe can be applied to detect HSO3- in living cells.


Assuntos
Benzotiazóis/química , Colorimetria/métodos , Corantes Fluorescentes/química , Fenóis/química , Espectrometria de Fluorescência/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Sulfitos/análise , Humanos , Limite de Detecção , Células MCF-7
9.
Medicine (Baltimore) ; 95(40): e5077, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27749580

RESUMO

INTRODUCTION: Currently, the options are limited for the treatment of patients who have failed 2 lines of chemotherapy for advanced lung squamous cell carcinoma (SCC). Recently, nivolumab, a fully human IgG4 programmed death 1 immune checkpoint inhibitor antibody, was approved to treat patients with advanced stage, relapsed/refractory lung SCC. Although nivolumab has demonstrated antitumor activity with survival benefit in Caucasian patients, its efficacy in Asian patients is unknown. CASE REPORT: In this report, we describe a Chinese patient with relapsed advanced stage lung SCC who had an excellent response to nivolumab after only 2 doses without any adverse effects. Immunohistochemical analysis indicated the tumor was stained positive for programmed death-ligand 1. CONCLUSION: To our knowledge, this is the first report of satisfactory efficacy of short-term nivolumab treatment in a Chinese patient with relapsed advanced-stage lung SCC. Further clinical trials in Asian countries are needed to test whether nivolumab immunotherapy is a safe and effective treatment for Asian patients with lung SCC.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Estadiamento de Neoplasias , Antineoplásicos/administração & dosagem , Carcinoma de Células Escamosas/diagnóstico , China , Relação Dose-Resposta a Droga , Evolução Fatal , Seguimentos , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Nivolumabe , Fatores de Tempo , Tomografia Computadorizada por Raios X
10.
Chem Asian J ; 11(13): 1971-81, 2016 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-27146450

RESUMO

The expansion of CAG repeats in the human genome causes the neurological disorder Huntington's disease. The small-molecule naphthyridine-azaquinolone NA we reported earlier bound to the CAG/CAG motif in the hairpin structure of the CAG repeat DNA. In order to investigate and improve NA-binding to the CAG repeat DNA and RNA, we conducted systematic structure-binding studies of NA to CAG repeats. Among the five new NA derivatives we synthesized, surface plasmon resonance (SPR) assay showed that all of the derivatives modified from amide linkages in NA to a carbamate linkage failed to bind to CAG repeat DNA and RNA. One derivative, NBzA, modified by incorporating an additional ring to the azaquinolone was found to bind to both d(CAG)9 and r(CAG)9 . NBzA binding to d(CAG)9 was similar to NA binding in terms of large changes in the SPR assay and circular dichroism (CD) as well as pairwise binding, as assessed by electron spray ionization time-of-flight (ESI-TOF) mass spectrometry. For the binding to r(CAG)9 , both NA and NBzA showed stepwise binding in ESI-TOF MS, and NBzA-binding to r(CAG)9 induced more extensive conformational change than NA-binding. The tricyclic system in NBzA did not show significant effects on the binding, selectivity, and translation, but provides a large chemical space for further modification to gain higher affinity and selectivity. These studies revealed that the linker structure in NA and NBzA was suitable for the binding to CAG DNA and RNA, and that the tricyclic benzoazaquinolone did not interfere with the binding.


Assuntos
DNA/metabolismo , Naftiridinas/química , Naftiridinas/farmacologia , Quinolonas/química , Quinolonas/farmacologia , RNA/metabolismo , Sequência de Bases , Sítios de Ligação , DNA/química , Humanos , Naftiridinas/síntese química , Conformação de Ácido Nucleico/efeitos dos fármacos , Quinolonas/síntese química , RNA/química
11.
Anal Sci ; 31(7): 663-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26165289

RESUMO

A bifunctional probe (FecNC), containing a recognition part and an electrochemical active center, was applied to electrochemical detection of GG mismatch duplexes. The preparation of gold electrodes modified by mismatch and complementatry duplexes was characterized by electrochemical impedance spectroscopy (EIS) and optimized for better detection in terms of self-assembly time, hybridization time, and incubation time. The interaction between FecNC and DNA duplexes modified on the surface of a gold electrode was explored by square wave voltammetry (SWV) and EIS. The results showed that the DNA duplexes with GG mismatch on the surface of a gold electrode was easily detected by the largest electrochemical signal of the bifunctional probe because of its selective binding to GG mismatches. The bifunctional probe could offer a simple, effective electrochemical detection of GG mismatches, and theoretical bases for development of electrochemical biosensors. Further, the method would be favorable for diagnosis of genetic diseases.


Assuntos
Pareamento Incorreto de Bases , Eletroquímica/métodos , Sondas Moleculares/química , Sequência de Bases , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , Eletrodos , Ouro/química , Hibridização de Ácido Nucleico , Propriedades de Superfície
12.
Biosens Bioelectron ; 74: 113-33, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26134290

RESUMO

In the diagnosis of genetic diseases and disorders, nanomaterials-based gene detection systems have significant advantages over conventional diagnostic systems in terms of simplicity, sensitivity, specificity, and portability. In this review, we describe the application of nanomaterials for disease-related genes detection in different methods excluding PCR-related method, such as colorimetry, fluorescence-based methods, electrochemistry, microarray methods, surface-enhanced Raman spectroscopy (SERS), quartz crystal microbalance (QCM) methods, and dynamic light scattering (DLS). The most commonly used nanomaterials are gold, silver, carbon and semiconducting nanoparticles. Various nanomaterials-based gene detection methods are introduced, their respective advantages are discussed, and selected examples are provided to illustrate the properties of these nanomaterials and their emerging applications for the detection of specific nucleic acid sequences.


Assuntos
Técnicas Biossensoriais/métodos , Testes Genéticos/métodos , Nanoestruturas/química , Nanotecnologia/métodos , Animais , Técnicas Biossensoriais/instrumentação , Colorimetria/instrumentação , Colorimetria/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Testes Genéticos/instrumentação , Humanos , Nanotecnologia/instrumentação , Espectrometria de Fluorescência/instrumentação , Espectrometria de Fluorescência/métodos , Análise Espectral Raman/instrumentação , Análise Espectral Raman/métodos
13.
Analyst ; 139(21): 5482-7, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25181952

RESUMO

A small molecule modified sensor was developed for the detection of XGG trinucleotide repeats (X = C, T) by electrochemical impedance spectroscopy. The sensor (NCD/MPA/Au) was fabricated by immobilizing the nucleic acid recognition molecule (NCD) on the surface of a gold electrode through a condensation reaction between the amino-terminal end of the NCD linker and carboxylic groups in 3-mercaptopropionic acid that were self-assembled on the electrode surface. After the sensor was incubated with trinucleotide repeats, electrochemical impedance spectroscopy was performed using [Fe(CN)6](3-/4-) as redox marker ions. XGG repeats (X = C, T) could be selectively detected based on the differences in charge transfer resistance (ΔRct) even in the presence of other trinucleotide repeats. The relationship between ΔRct and lg [concentration of CGG repeats] for the sensor was linear from 1 nM to 1 µM, enabling the quantification of the number of repeats. The electrochemical impedance sensor provides a simple and rapid method to detect trinucleotide repeats without requiring labelling and immobilizations of DNA, making it promising for the early diagnosis of neurodegenerative diseases; the sensor may be further extended to the detection of other special sequences of DNA.


Assuntos
Espectroscopia Dielétrica/instrumentação , Eletrodos , Ouro/química , Repetições de Trinucleotídeos , Limite de Detecção
14.
Biosens Bioelectron ; 49: 282-9, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-23774165

RESUMO

We have developed a simple and label-free electrochemical assay to detect CGG trinucleotide repeat. For this purpose, a new bifunctional probe (FecNCD2) was developed, in which a recognition part (naphthyridine carbamate dimmer, NCD) was connected with an electro-active part (ferrocenyl group) using a chain of -CO-NH-CH2-CH2-. The results of circular dichroismic measurements indicated that FecNCD2 exhibited a superior performance for selective binding to CGG trinucleotide repeats compared to a previous bifunctional electrochemical probe connected with shorter linker -CH2- (FecNCD1). Then, the electrochemical properties of FecNCD2 were evaluated and were found to show a good redox response due to the ferrocene moiety. Owing to the high performances of FecNCD2, the label-free electrochemical biosensor for CGG repeats was constructed by immobilizing them onto gold disk electrode and by using FecNCD2 as an electrochemical probe in solution. Further CGG repeats in solution were confirmed to be detectable using the CGG modified biosensor in competitive experiments, i.e., by treating it in test solutions containing FecNCD2 and d(CGG)10 or others. No interference of ct-DNA on the CGG detection was also confirmed with this approach. The strategy should have significant potential for the development of versatile and low-cost biosensor for early diagnosis and treatment of neurodegenerative diseases associated with trinucleotide repeats.


Assuntos
Técnicas Biossensoriais/métodos , DNA/análise , Técnicas Eletroquímicas/métodos , Repetições de Trinucleotídeos , Animais , Bovinos , Compostos Ferrosos/química , Metalocenos , Naftiridinas/química , Oxirredução , Sensibilidade e Especificidade
15.
Bioorg Med Chem Lett ; 23(2): 558-61, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23245513

RESUMO

A dimeric form of N-methoxycarbonyl-2-amino-1,8-naphthyridine (MCND) connected at the C2 position with a three-atom linker was examined for the binding to mismatches in double stranded RNA. Despite the fully complementary hydrogen bonding groups to guanine, MCND did not bind to guanine-guanine mismatch but did to adenine-adenine mismatch. The base pairs flanking the mismatch had weak effect on the binding, with showing the strongest binding to the A-A mismatch in the CAG/CAG sequence. The A-A mismatch in the GAC/GAC sequence was a poor substrate for the MCND binding. A monomeric derivative of MCND and another derivative lacking a methylcarbamate group showed negligilble binding to the A-A mismatch and the sequence selectivity. These results are important clues for the better molecular design of RNA binding small molecules.


Assuntos
Adenina/química , Pareamento Incorreto de Bases , Naftiridinas/química , RNA de Cadeia Dupla/metabolismo , Dimerização , Ligações de Hidrogênio , Modelos Moleculares , Naftiridinas/metabolismo , Compostos Organofosforados/química , Compostos Organofosforados/metabolismo , RNA de Cadeia Dupla/química
16.
Biosens Bioelectron ; 42: 36-40, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23202327

RESUMO

A new electrochemical assaying approach with label-free to identify GG mismatch in DNA duplexes was developed by applying a new double functional probe (FecNC), ferrocenyl modified naphthyridine derivative, which contain recognition domain (naphthyridine derivative) and electroactive center (ferrocenyl group). The double functional probe exhibited not only the excellent electrochemical response devoted from ferrocenyl but also high selective electrochemical signal "off" for G-G mismatch duplex. The interaction was also verified by melting temperature and circular dichroismic spectra (CD). The electrochemical investigation showed that the redox of FecNC was a diffusion-controlled process and the diffusion coefficient of bound-FecNC was much smaller than free FecNC. The correlation between the current of FecNC and concentration of GG mismatch duplex indicated that the bind saturation point was about at a 1:1 mole ratio. The novel double functional electrochemical probe might provide a versatile and low-cost way to detect single nucleotide polymorphisms, which could be found extensive applications in the diagnosis of the genetic diseases.


Assuntos
Pareamento Incorreto de Bases/genética , DNA/química , Compostos Ferrosos/química , Naftiridinas/química , Técnicas Biossensoriais , Dicroísmo Circular , Técnicas Eletroquímicas , Humanos , Polimorfismo de Nucleotídeo Único/genética
17.
Bioorg Med Chem Lett ; 22(5): 2000-3, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22326165

RESUMO

Unusual expansion of trinucleotide repeats has been identified as a common mechanism of hereditary neurodegenerative diseases. Although the actual mechanism of repeat expansion remains uncertain, trinucleotide repeat instability may be related to the increased stability of an alternative DNA hairpin structure formed in the repeat sequences. Here we report that a synthetic ligand naphthyridine carbamate dimer (NCD) selectively bound to and stabilized an intra-stranded hairpin structure in CGG repeat sequences. The NCD-CGG hairpin complex was a stable structure that efficiently interfered with DNA replication by Taq DNA polymerase. Considering the sequence preference of NCD, the use of NCD would be valuable to investigate the genetic instabilities of CGG/CCG repeat sequences in human genomes.


Assuntos
DNA/química , Naftiridinas/química , Naftiridinas/farmacologia , Conformação de Ácido Nucleico/efeitos dos fármacos , Repetições de Trinucleotídeos/efeitos dos fármacos , Sequência de Bases , Carbamatos/química , Carbamatos/farmacologia , Replicação do DNA/efeitos dos fármacos , Dimerização , Humanos , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia
19.
Chemistry ; 15(40): 10641-8, 2009 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-19718722

RESUMO

A newly designed ligand, methylcarbamoylnaphthyridine dimer (MCND), was synthesized and characterized. Ligand binding to d(GAA)(10) was investigated by UV thermal denaturation, circular dichroism spectroscopy, surface plasmon resonance, and cold-spray-ionization time-of-flight mass spectrometry. The results indicated that MCND bound to the d(GAA)(n) repeat to form a stable hairpin structure with a major binding stoichiometry of 3:1. The most likely binding site was identified as the G-G mismatch in the AGA/AGA triad. The polymerase stop assay showed that MCND binding to the d(GAA)(n) repeat effectively interfered with the extension of the primer at the first two GAA sites on the template with both prokaryotic Taq DNA polymerase and human DNA polymerase alpha.


Assuntos
Replicação do DNA , Modelos Moleculares , Repetições de Trinucleotídeos/efeitos dos fármacos , Sequência de Bases , DNA Polimerase I/metabolismo , Humanos , Estrutura Molecular , Taq Polimerase/metabolismo
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