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1.
Zhongguo Zhong Yao Za Zhi ; 48(22): 6075-6081, 2023 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-38114214

RESUMO

With the continuous exploration of microemulsions as solvents for traditional Chinese medicine extraction, polyoxyethy-lene(35) castor oil(CrEL), a commonly used surfactant, is being utilized by researchers. However, the problem of detecting residues of this surfactant in microemulsion extracts has greatly hampered the further development of microemulsion solvents. Based on the chemical structures of the components in CrEL and the content determination method of castor oil in the 2020 edition of the Chinese Pharmacopoeia(Vol. Ⅳ), this study employed gas chromatography(GC) and single-factor experiments to optimize the preparation method of methyl ricinoleate from CrEL. The conversion coefficient between the two was validated, and the optimal sample preparation method was used to process microemulsion extracts of Zexie Decoction from three batches. The content of methyl ricinoleate generated was determined, and the content of CrEL in the microemulsion extracts of Zexie Decoction was calculated using the above conversion coefficient. The results showed that the optimal preparation method for CrEL was determined. Specifically, 10 mL of 1 mol·L~(-1) KOH-methanol solution was heated at 60 ℃ for 15 min in a water bath. Subsequently, 10 mL of boron trifluoride etherate-methanol(1∶3) solution was heated at 60 ℃ for 15 min in a water bath, followed by extraction with n-hexane twice. CrEL could stably produce 20.84% methyl ricinoleate. According to this conversion coefficient, the average mass concentration of CrEL in the three batches of Zexie Decoction microemulsion extracts was 11.94 mg·mL~(-1), which was not significantly different from the CrEL mass concentration of 11.57 mg·mL~(-1) during microemulsion formulation, indicating that the established content determination method of this study was highly accurate, sensitive, and repeatable. It can be used for subsequent research on microemulsion extracts of Zexie Decoction and provide a reference for quality control of other drug formulations containing CrEL.


Assuntos
Óleo de Rícino , Polietilenoglicóis , Polietilenoglicóis/química , Metanol , Tensoativos/química , Solventes , Água/química , Emulsões/química
3.
ACS Omega ; 8(13): 12259-12267, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37033822

RESUMO

Glioblastoma is considered the most fatal malignant brain tumor that starts from the central nervous system (CNS), where the blood-brain barrier (BBB) remains the biggest challenge for active targeting of drugs in malignant brain tumor. Thereby, we have designed a paclitaxel PTX@ANG/FA-NPs hybrid novel nanodrug delivery system that can overcome the clinical BBB. The structural and morphological characterization of PTX@ANG/FA-NPs confirmed successful synthesis of nanomicelles with the size range of about 160 to 170 nm. The overall repressive effect of PTX@ANG/FA-NPs on human glioblastoma U251 cells was 1.2-times that of PTX alone. In vitro cellular uptake assay also demonstrated that the dual-targeted nanoparticles (NPs) were more easily taken up by glioblastoma U251 cells. Although the antiglioblastoma activity was confirmed by cell migration assay, apoptosis assay, and cellular uptake assay, the absorption was studied by in vivo fluorescence imaging and brain distribution. The synthesized PTX@ANG/FA-NPs probe significantly inhibited the migration of U251 within the cells and promoted the apoptosis process. Moreover, the RhB@ANG/FA-NPs and PTX@ANG/FA-NPs showed higher accumulating potential at sites of tumor BBB disruption. The novel nanodrug delivery system mediated enhanced distribution of drugs at the targeted site for therapeutics efficacies against glioblastomas across the BBB.

4.
Zhongguo Zhong Yao Za Zhi ; 46(10): 2481-2488, 2021 May.
Artigo em Chinês | MEDLINE | ID: mdl-34047094

RESUMO

The paclitaxel-loaded and folic acid-modified poly(lactic-co-glycolic acid) nano-micelles(PTX@FA-PLGA-NMs) were prepared by the emulsion solvent evaporation method, and the parameters of paclitaxel-loaded nano-micelles were optimized with the particle size and PDI as evaluation indexes. The morphology of the nano-micelles was observed by transmission electron microscopy(TEM), and the stability, drug loading and encapsulation efficiency were systematically investigated. In vitro experiments were performed to study the cytotoxic effects of nano-micelles, apoptosis, and cellular uptake. Under the optimal parameters, the nano-micelles showed the particle size of(125.3±1.2) nm, the PDI of 0.086±0.026, the zeta potential of(-20.0±3.8) mV, the drug loading of 7.2%±0.75%, and the encapsulation efficiency of 50.7%±1.0%. The nano-micelles were in regular spherical shape as observed by TEM. The blank FA-PLGA-NMs exhibited almost no inhibitory effect on the proliferation and growth of tumor cells, while the drug-loaded nano-micelles and free PTX exhibited significant inhibitory effects. The IC_(50) of PTX@FA-PLGA-NMs and PTX was 0.56 µg·mL~(-1) and 0.66 µg·mL~(-1), respectively. The paclitaxel-loaded nano-micelles were potent in inhibiting cell migration as assessed by the scratch assay. PTX@FA-PLGA-NMs had good pro-apoptotic effect on cervical cancer HeLa cells and significantly promoted the uptake of HeLa cells. The results of in vitro experiments suggested that PTX@FA-PLGA-NMs could target and treat cervical cancer HeLa cells. Therefore, as nanodrug carriers, PTX@FA-PLGA-NMs with anti-cancer activity are a promising nano-system for improving the-rapeutic effects on tumors.


Assuntos
Antineoplásicos Fitogênicos , Neoplasias do Colo do Útero , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Portadores de Fármacos , Feminino , Ácido Fólico , Glicolatos , Células HeLa , Humanos , Micelas , Paclitaxel , Tamanho da Partícula , Neoplasias do Colo do Útero/tratamento farmacológico
5.
Acta Biomater ; 127: 287-297, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33831570

RESUMO

Organic fluorophores/photosensitizers have been widely used in biological imaging and photodynamic and photothermal combination therapy in the first near-infrared (NIR-I) window. However, their applications in the second near-infrared (NIR-II) window are still limited primarily due to low fluorescence quantum yields (QYs). Here, a boron dipyrromethene (BDP) is created as a molecularly engineered thiophene donor unit with high QYs to the redshift. Thiophene insertion initiates substantial redshifts of the absorbance as compared to its counterparts in which iodine is introduced. The fluorescent molecule can be triggered by an NIR laser with a single wavelength, thereby producing emission in the NIR-II windows. Single NIR laser-triggered phototherapeutic nanoparticles (NPs) are developed by encapsulating the BDP and the chemotherapeutic drug docetaxel (DTX) by using a synthetic amphiphilic poly(styrene-co-chloromethyl styrene)-graft-poly(ethylene glycol) functionalized with folic acid (FA). These BDP-T-N-DTX-FA NPs not only show superior solubility and high singlet oxygen QY (ΦΔ=62%) but also demonstrate single NIR laser-triggered multifunctional characteristics. After intravenous administration of the NPs into 4T1 tumor-bearing mice, the accumulation of the NPs in the tumor showed a high signal-to-background ratio (11.8). Furthermore, 4T1 tumors in mice were almost eradicated by DTX released from the BDP-T-N-DTX-FA NPs under single NIR laser excitation and the combination of photodynamic therapy (PDT) and photothermic therapy (PTT). STATEMENT OF SIGNIFICANCE: The application of organic photosensitizers is still limited primarily due to low fluorescence quantum yields (QYs) in the second near-infrared (NIR-II) window. Here, a boron dipyrromethene (BDP) as a molecularly engineered thiophene donor unit with high QYs to the redshift is created. Phototherapeutic nanoparticles (NPs) are developed by encapsulating the BDP and docetaxel (DTX) using a synthetic amphiphilic poly(styrene-co-chloromethyl styrene)-graft-poly(ethylene glycol) functionalized with folic acid (FA). These BDP-T-N-DTX-FA NPs not only show high singlet oxygen QY (ΦΔ=62%) but also demonstrate single NIR laser-triggered multifunctional characteristics and a high signal-to-background ratio (11.8). Furthermore, 4T1 tumors in mice were almost eradicated by DTX released from the BDP-T-N-DTX-FA NPs under single NIR laser excitation and the PDT/PTT combination therapy.


Assuntos
Nanopartículas , Fotoquimioterapia , Animais , Linhagem Celular Tumoral , Camundongos , Imagem Óptica , Fármacos Fotossensibilizantes/farmacologia , Tiofenos/farmacologia
6.
Front Pharmacol ; 11: 898, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612532

RESUMO

PHARMACOLOGICAL RELEVANCE: Paclitaxel (PTX) is currently the only botanical drug that can control the growth of cancer cells. Paclitaxel is widely used in the treatment of breast cancer, ovarian cancer, uterine cancer, non-small cell lung cancer and other cancers. AIM: Folate receptor and integrin α v ß 3 are highly expressed on the surface of human breast cancer cells MCF-7. Folic acid and arginine-glycine-aspartate (Arg-Gly-Asp, RGD) tripeptide sequence have a high affinity for folate receptor and integrin α v ß 3, respectively. To enhance the effect on breast cancer, we constructed the folate acid and RGD peptide dual-targeted (MSNs-NH2-FA-RGD) drug-carrier based on mesoporous silica nanoparticles. METHODS: The structure of mesoporous nanocarriers was characterized by Fourier transform infrared spectroscopy, nitrogen adsorption-desorption analysis, transmission electron microscopy, laser particle size analyzer, and thermogravimetric analysis. Paclitaxel was chosen as the model drug. The targeting-ability was verified by observing the uptake of mesoporous carriers loaded with rhodamine in MCF-7, MCF-10A, and HeLa cells using a fluorescence microscope. The cytotoxicity of the blank carrier MSNs-NH2-FA-RGD and the efficacy of the drug carrier PTX@MSNs-NH2-FA-RGD were assessed by cell experiments. RESULTS: The characterization showed successful construction of a dual-targeted mesoporous silica nanocarrier. Obvious differences were detected in the fluorescence intensity of the three cell lines. The results of the pharmacological tests indicated that the blank nanoparticles do not cause any apparent toxicity on these cells. The IC50 of free PTX and PTX@MSNs-NH2-FA-RGD on MCF-7 cells line treated for 48 h were 35.25±2.57 ng·ml-1 and 22.21±3.4 ng·ml-1 respectively, which indicated that the inhibitory efficacy of PTX@MSNs-NH2-FA-RGD on MCF-7 was 1.6 times than that of free PTX. CONCLUSIONS: The dual-targeted nanocarrier MSNs-NH2-FA-RGD could target breast cancer cells, and sever as a potential candidate in future of drug development.

7.
Sci Rep ; 10(1): 5994, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32265463

RESUMO

Two rare N-ß-D-glucopyranosyl-1H-indole-3-acetic acid conjugates, N-[2-(1-ß-D-glucopyranosyl)-1H-indol-3-yl)acetyl]-L-glutamic acid (1) and N-[2-(1-ß-D-glucopyranosyl)-1H-indol-3-yl)acetyl]-L-aspartic acid (2) were isolated from Ginkgo biloba. The structures were elucidated by analyses of HRMS and NMR spectroscopic data. In addition, a simplified and efficient synthetic route for compounds 1 and 2 is also disclosed to determine the absolute configurations of them. This concise syntheses of compounds 1 and 2 may facilitate studies of the biology of this type alkaloids. Compounds 1 and 2 were also tested for their cytotoxic and anti-inflammatory activities. The biological evaluation showed that compounds 1 and 2 led to the decrease of interleukin (IL)-6, nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 at mRNA level in lipopolysaccharide (LPS)-stimulated murine macrophage RAW264.7 cells.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Ginkgo biloba/química , Glicosídeos/química , Glicosídeos/farmacologia , Animais , Anti-Inflamatórios/isolamento & purificação , Glicosídeos/isolamento & purificação , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Interleucina-6/antagonistas & inibidores , Interleucina-6/metabolismo , Lipopolissacarídeos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/metabolismo , Células RAW 264.7
8.
J Pharm Pharm Sci ; 22(1): 424-439, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31509503

RESUMO

Traditional Chinese Medicines (TCMs) have been used for more than 3,000 years. However, most TCMs are used based on previous experience, and their exact mechanisms are still unclear. Proteomics, as a major component of systems biology, is an appropriate tool that could bring breakthroughs in the study of pharmacological mechanisms of TCMs. Researchers made substantial progress by using the proteomics approach to investigate the mechanism of TCMs. In this review, we summarize the current applications of proteomics in the mechanistic study of TCMs. Proteomics technologies and strategies that might be used in the future to enhance the study of TCMs are also discussed.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Neoplasias/tratamento farmacológico , Proteômica , Animais , Doenças Cardiovasculares/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Inflamação/tratamento farmacológico , Hepatopatias/tratamento farmacológico , Medicina Tradicional Chinesa , Doenças do Sistema Nervoso/tratamento farmacológico
9.
Molecules ; 24(14)2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31336730

RESUMO

To explore the optimum conditions for the extraction of anthocyanins and flavonols from bog bilberry (Vaccinium uliginosum L.) marc on a single-factor experimental basis, a response surface methodology was adopted for this intensive study. The extraction procedure was carried out in a Waring blender and followed an ultrasonic bath, and the natural antioxidant carnosic acid was added to inhibit oxidation. The optimum extraction conditions were as follows: a volume fraction of ethanol of 70%, an antioxidant content of 0.02% (the mass of sample) carnosic acid, a liquid-solid ratio of 16 mL/g, a homogenization time of 3 min, a reaction temperature of 55 °C, an ultrasound irradiation frequency of 80 kHz, an ultrasound irradiation power of 200 W, and an ultrasound irradiation time of 40 min. Satisfactory yields of anthocyanins (13.95 ± 0.37 mg/g) and flavonols (3.51 ± 0.16 mg/g) were obtained. The experimental results showed that the carnosic acid played an effective antioxidant role in the extraction process of anthocyanins and flavonols with a green and safety guarantee.


Assuntos
Antocianinas/isolamento & purificação , Antocianinas/farmacologia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Mirtilos Azuis (Planta)/química , Extração Líquido-Líquido , Ondas Ultrassônicas , Abietanos , Antocianinas/química , Antioxidantes/química , Cromatografia Líquida de Alta Pressão , Flavonóis/química , Flavonóis/isolamento & purificação , Flavonóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Solventes , Temperatura
10.
J Zhejiang Univ Sci B ; 20(1): 84-94, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30614232

RESUMO

Peach brown rot, caused by Monilinia fructicola, is one of the most serious peach diseases. A strain belonging to the Actinomycetales, named Streptomyces blastmyceticus JZB130180, was found to have a strong inhibitory effect on M. fructicola in confrontation culture. Following the inoculation of peaches in vitro, it was revealed that the fermentation broth of S. blastmyceticus JZB130180 had a significant inhibitory effect on disease development by M. fructicola. The fermentation broth of S. blastmyceticus JZB130180 had an EC50 (concentration for 50% of maximal effect) of 38.3 µg/mL against M. fructicola, as determined in an indoor toxicity test. Analysis of the physicochemical properties of the fermentation broth revealed that it was tolerant of acid and alkaline conditions, temperature, and ultraviolet radiation. In addition, chitinase, cellulase, and protease were also found to be secreted by the strain. The results of this study suggest that S. blastmyceticus JZB130180 may be used for the biocontrol of peach brown rot.


Assuntos
Ascomicetos/patogenicidade , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Prunus persica/microbiologia , Streptomyces/fisiologia , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Celulase/metabolismo , Quitinases/metabolismo , Fermentação , Frutas/microbiologia , Controle Biológico de Vetores/métodos , Filogenia , Sideróforos/metabolismo , Streptomyces/classificação , Streptomyces/genética
11.
Eur J Pharmacol ; 842: 10-19, 2019 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-30355510

RESUMO

Jolkinolide B (JB), which is isolated from the dried root of Euphorbia fischeriana Steud., has been reported to possess various therapeutic effects, such as treatment of edema and abdominal distention and protection against acute lung injury, and it has also been reported to have anti-inflammatory even antitumor properties. Thus, JB has always been considered a promising anticancer drug candidate. In the current work, a cellular metabolomics evaluation based on the nuclear magnetic resonance (NMR) approach was applied to investigate the mechanism of JB in HepG2 cells. In addition, biological assays such as the MTT assay, DAPI staining and the Annexin V-FITC/PI assay were implemented to evaluate cell viability and apoptosis in JB-treated cells. Subsequently, we used multivariate statistical analyses, such as principal component analysis (PCA) and orthogonal projection to latent structure with discriminant analysis (OPLS-DA) to identify metabolic biomarkers. In total, 36 metabolites in the cell extract samples and 30 metabolites in the cell culture media samples were clearly identified to be altered after the treatment. Variations in the specific metabolites suggested that HepG2 cells that were exposed to JB displayed the disordered effects in multiple metabolic pathways, such as the tricarboxylic acid cycle, amino acid metabolism, GSH synthesis and pyruvate metabolism. NMR-based cell metabolomics provided a holistic method for the identification of JB's antitumor mechanisms and the exploration of its potential applications in preclinical and clinical studies.


Assuntos
Antineoplásicos/farmacologia , Diterpenos/farmacologia , Metabolômica , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Espectroscopia de Ressonância Magnética
12.
Asian-Australas J Anim Sci ; 30(12): 1724-1732, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28427255

RESUMO

OBJECTIVE: The objective of this experiment was to determine apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of crude protein (CP) and amino acid (AA) in 15 sources of soybean meal (SBM) produced from soybeans from different countries and subsequently to establish equations for predicting the AID and SID in SBM based on their chemical composition. METHODS: Eighteen barrows (57.9±6.1 kg) fitted with a simple T-cannula were allotted into three 6×6 Latin square designs. Each period comprised a 6-d adaption period followed by a 2-d collection of ileal digesta. The 15 test diets included SBM as a sole source of AA in the diet. Another nitrogen-free diet was used to measure basal endogenous losses of CP and AA. Chromic oxide (0.3%) was used as an inert marker in each diet. RESULTS: The AID of lysine in SBM from China and USA tended to be greater than in SBM from Brazil (p<0.10). The SID of valine and proline in SBM from China was greater than in SBM from Brazil (p<0.05). The SID of lysine, threonine, cysteine and glycine in SBM from China tended to be greater than in SBM from Brazil (p<0.10). From a stepwise regression analysis, a series of AID and SID prediction equations were generated. The best fit equations for lysine in SBM were: AID lysine = 1.16 sucrose-1.81 raffinose+82.10 (R2 = 0.69, p<0.01) and SID lysine = 1.14 sucrose-1.93 raffinose-0.99 ether extract (EE)+85.26 (R2 = 0.77, p<0.01). CONCLUSION: It was concluded that under the conditions of this experiment, the oligosaccharides (such as sucrose and raffinose) can be used to predict the AID and SID of AA in SBM with reasonable accuracy.

13.
Arch Anim Nutr ; 69(1): 30-45, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25608731

RESUMO

The objective of this study was to evaluate the effects of particle size and drying methods of corn on growth performance of weaned piglets. Crossbreed weaned piglets (n = 192; Duroc × Landrace × Large White) were assigned to one of four treatments (2 × 2 factorial arrangement). All piglets were fed corn-soybean meal diets and treatments were (1) hot air-dried and coarsely ground corn, (2) hot air-dried and finely ground corn, (3) sun-dried and coarsely ground corn and (4) sun-dried and finely ground corn. The results showed that finely ground corn (FGC) improved the performance of piglets. Additionally, the apparent total tract digestibility (ATTD) of gross energy (GE) and ether extract (EE) were increased by FGC, but the drying methods did not affect the performance of piglets or ATTD. Furthermore, smaller particle size significantly decreased the intestinal permeability, which was also not influenced by drying methods. FGC increased the total number of white blood cells, but not other blood parameters. Finally, the level of serum interleukin-1 was decreased by fine grinding and that of serum tumour necrosis factor α was decreased by sun drying. Conversely, these characteristics of weaned piglets can hardly have been affected either by the corn drying method or its interaction with grinding methods.


Assuntos
Ração Animal/análise , Dieta/veterinária , Digestão/fisiologia , Suínos/crescimento & desenvolvimento , Zea mays/química , Fenômenos Fisiológicos da Nutrição Animal , Animais , Feminino , Intestinos/efeitos dos fármacos , Intestinos/fisiologia , Masculino , Suínos/sangue , Suínos/imunologia
14.
J Am Chem Soc ; 135(10): 3748-51, 2013 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-23339662

RESUMO

Portable devices with the advantages of rapid, on-site, user-friendly, and cost-effective assessment are widely applied in daily life. However, only a limited number of quantitative portable devices are commercially available, among which the personal glucose meter (PGM) is the most successful example and has been the most widely used. However, PGMs can detect only blood glucose as the unique target. Here we describe a novel design that combines a glucoamylase-trapped aptamer-cross-linked hydrogel with a PGM for portable and quantitative detection of non-glucose targets. Upon target introduction, the hydrogel collapses to release glucoamylase, which catalyzes the hydrolysis of amylose to produce a large amount of glucose for quantitative readout by the PGM. With the advantages of low cost, rapidity, portability, and ease of use, the method reported here has the potential to be used by the public for portable and quantitative detection of a wide range of non-glucose targets.


Assuntos
Trifosfato de Adenosina/análise , Aptâmeros de Nucleotídeos/química , Automonitorização da Glicemia , Cocaína/análise , Hidrogel de Polietilenoglicol-Dimetacrilato/química , alfa-Glucosidases/química , Trifosfato de Adenosina/metabolismo , Amilose/química , Amilose/metabolismo , Aptâmeros de Nucleotídeos/metabolismo , Biocatálise , Cocaína/metabolismo , Glucose/análise , Glucose/biossíntese , Humanos , Hidrogel de Polietilenoglicol-Dimetacrilato/metabolismo , Hidrólise , alfa-Glucosidases/metabolismo
15.
Anal Chem ; 84(19): 8383-90, 2012 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-22954361

RESUMO

Because of their ability to greatly enhance the low natural peroxidase activity of hemin, G-quadruplex-based DNAzymes have been widely used as an alternative to peroxidases for many colorimetric, chemiluminescent, or visual detections of metal ions, small molecules, nucleic acids, proteins, and cancer cells. To obtain G-quadruplex-based DNAzymes with better peroxidase activity, we designed three 81-nt ssDNA libraries containing 25%, 35%, and 45% guanine bases, respectively, at the 45-nt random regions to evolve hemin-binding DNA aptamers using hemin-agarose beads by SELEX (systematic evolution of ligands by exponential enrichment). Some G-rich sequences were obtained after 6 rounds of selection and optimized for stronger binding affinity to hemin and higher peroxidase activity. Our results show that the truncated aptamer [B7]-3-0 folds into compact parallel G-quadruplex structure and exhibits the highest peroxidase activity and strong binding affinity to hemin with 29 ± 4 nM of K(d). It was found that the core G-motifs sequences with 5'-flanking nucleotides exhibit higher peroxidase activity than those with 3'-flanking nucleotides. The numbers of 5'-flanking nucleotides also influence peroxidase activity. In addition, 2'-O-methyl modification facilitates the self-assembly of parallel G-quadruplex [B7]-3-0 and significantly promotes peroxidase activity. This study identifies a G-quadruplex sequence with peroxidase-like activity higher than any other sequences reported so far, which could be potentially used to improve the analytical performance of a wide variety of peroxidase-based bioassays.


Assuntos
Quadruplex G , Peroxidases/química , Técnica de Seleção de Aptâmeros , Aptâmeros de Nucleotídeos/química , Guanina/química , Hemina/química , Peroxidases/metabolismo , Sefarose/química
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