MICROBIAL PATHOGENESIS
·
2018
·
IF 2.332
Tengteng Lv,Tongxiang Song,Huijie Liu,Ruibing Peng,Xiamin Jiang,Weiwei Zhang,Qingxi Han
Vibrio alginolyticus is a ubiquitous marine opportunistic pathogen that can infect various hosts in marine environment. In the present study, V. alginolyticus strain Wz11 was isolated from diseased cuttlefish , Sepia pharaonis , with 20% of promoted death and high survival capacity in skin mucus and tissue liquid. Its growth, siderophore production, and expressions of haemolysin and swarming related genes were characterized under iron limited conditions. The minimal inhibitory concentration (MIC) of 2,2′-dipyridyl (DP) to V. alginolyticus strain Wz11 was 640 μM. While growth of V. alginolyticus strain Wz11 was inhibited by DP , production of iron-seizing substances, haemolytic activity and swarming motility were increased. Moreover, expressions of haemolysin related genes tlh , tdh and vah and flagellar related genes flgH , fliC , fliD and fliS were also characterized using real-time reverse transcriptase PCR. Expression of tdh was up-regulated to 7.7-fold, while expressions of tlh and vah were down-regulated to 0.016-fold and 0.03-fold, respectively. The expression of fliC , flgH , fliD and fliS was up-regulated to 4.9-, 3.8-, 8.6- and 4.5-fold, respectively. Concluded from our results suggested that V. alginolyticus strain Wz11 was considered as a potential pathogen of S. pharaonis , and iron level played an important role in the production of iron-seizing substances, and activities of haemolysin and bacterial swarming as well as their related gene expressions.
研究领域:
微生物学
·
海洋生物学
·
水产养殖学
✓ 已验证
DOI
PubMed
高影响因子
Infection and Drug Resistance
·
2018
·
IF 3.443
Yufeng Du,Li Liu,Chunping Zhang,Yani Zhang
Staphylococcus aureus is becoming increasingly intractable because of its ability to acquire antimicrobial resistance and secrete numerous virulence factors that can exacerbate inflammation. Alpha-hemolysin (Hla) is a pore-forming virulence factor produced by S. aureus that can self-assemble into heptameric mushroom-structured pores in target cell membranes, leading to cell lysis and death. In the present study, we sought to better understand the mechanism underlying hemolysis and the oligomerization of Hla by creating nine mutants with single amino acid changes in different positions of the Hla protein: N17C, T18C, P103C, N105C, M113C, T117C, N121C, D128C, and T129C. The results showed that the P103C and N105C mutations, which are located in the triangle region, significantly diminished hemolysis and heptamer formation when compared with the wild-type Hla protein. This suggests that the P103 and N105 residues play key roles in the assembly of the Hla pore. These results improve our understanding of the mechanism underlying the pore-forming ability of Hla.
研究领域:
微生物学
·
分子生物学
·
感染与免疫
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2010
·Vol. 7
·期 1
·87-94
·
IF 6.171
Yi-Lun Ying,Hai-Yan Wang,Todd C. Sutherland,Yi-Tao Long
An aptamer is a specific oligonucleotide sequence that spontaneously forms a secondary structure capable of selectively binding an analyte. An aptamer’s conformation is the key to specific binding of a target molecule, even in the case of very closely related targets. Nanopores are a sensitive tool for the single-molecule analysis of DNA, peptides, and proteins transporting through the pore. Herein, a single α -hemolysin natural nanopore is utilized to sense the conformational changes of an adenosine 5’-triphosphate (ATP)-binding aptamer (ABA). The known DNA sequence of the ABA is used as a model to develop real-time monitoring of molecular conformational changes that occur by binding targets. The native, folded ABA structure has a nanopore unfolding time of 4.17 ms, compared with 0.29 ms for the ABA:ATP complex. A complementary 14-mer strand, which binds the ABA sequence in the key nucleic acids responsible for folding, forms linear duplex DNA, resulting in a nanopore transit time of 0.50 ms and a higher capture probability than that of the folded ABA oligomer. Competition assays between the ABA:ATP and ABA:reporter complexes are carried out, and the results suggest that the ABA:ATP complex is formed preferentially. The nanopore allows for the detection of an ABA in its folded, ATP-bound, and linear conformations.
研究领域:
分子生物学
·
生物传感器
·
核酸化学
·
单分子检测
·
转化医学
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Rikun Cui,Linna Li,Lili Liu,Zhen Li,Zhenzhao Wang,Xingtong Liu,Lei Tian,Fujun Yao,Xiaofeng Kang,Yanli Guo
Nucleic acid aptamers, which are short single-stranded RNA or DNA molecules, undergo conformational changes upon recognizing small molecules. However, their structural characterization is challenging due to the flexibility of single-stranded oligonucleotides. Nanopores provide a sensitive method for single-molecule analysis of molecular conformational changes as they transport through the pore. In this study, we employed α-hemolysin (α-HL) nanopore with high spatiotemporal resolution to investigate the conformational changes of DNA aptamer (ADO-23) upon binding to adenosine (Ado) molecules. Unlike the events generated by the aptamer alone, the DNA-Ado complex produced two distinct new characteristic events, indicating the formation of two unique secondary structures. By analyzing current events, the structures formed by the DNA-Ado complex were speculated to be hairpin DNA and G-quadruplex (G4) DNA. Furthermore, we demonstrated the potential of the aptamer as a chiral selector within the nanopore. The results showed that the aptamer specifically bound to D-Ado and not to L-Ado. Finally, we realized specific and sensitive detection of small molecule Ado by α-HL pore, with a detection limit as low as 10.5 nM, and successfully applied it to the detection of real human serum samples. The nanopore platform provides a powerful tool for studying small molecule-biomolecule conformational changes, and we constructed sensors for detecting adenosine through the aptamer. This work also offers a promising new approach to the recognition of enantiomers at the single-molecule level.
研究领域:
生物物理学
·
分子生物学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ANALYST
·
2019
·Vol. 144
·期 13
·4081-4085
·
IF 4.019
Yuan-Min Liu,Xiu-Yu Fang,Fang Fang,Zhi-Yong Wu
Chelerythrine (CHE) is one of the potential drugs for cancer treatments. The interaction between hairpin DNA and CHE has been investigated by spectral and mass spectrometry methods. In this paper, the stability of hairpin DNA with different loop bases and its interaction with CHE were explored with a single α-hemolysin (α-HL) nanopore sensing interface. The results showed that the characteristic current pulses not only relate to the loop composition changes of the hairpin DNA, but also provide interaction information between CHE and the hairpin DNA molecules. The dwell time of current pulses for hairpin DNA was significantly increased (hundreds of ms) due to the addition of CHE, and two characteristic current distributions were recognized for the hairpin with T3 and C3 loops. The two characteristic current groups could be ascribed to the hairpin DNA and the ones with CHE. This study indicates that it is possible to study the interaction between single CHE and single hairpin DNA molecules by the single-nanopore sensing interface as an alternative method to conventional spectrometric methods for therapeutic mechanism and drug screening purposes.
研究领域:
生物物理
·
分子生物学
·
纳米技术
·
癌症研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Yun-Dong Yin,Lei Yang,Xi-Tong Song,Jun Hu,Fang-Fang Chen,Ming Xu,Zhi-Yuan Gu
The high expression of Spermidine/spermine N1-acetyltransferase (SSAT-1) is an important indicator in early cancer diagnosis. Here, we developed a nanopore-based methodology with γ-cyclodextrin as an adaptor to detect and quantify acetylamantadine, the specific SSAT-1-catalyzed product from amantadine, to accordingly reflect the activity of SSAT-1. We employ γ-cyclodextrin and report that amantadine cannot cause any secondary signals in γ-cyclodextrin-assisted α-HL nanopore, while its acetylation product, acetylamantadine, does. This allows γ-cyclodextrin to practically detect acetylamantadine in the interference of excessive amantadine, superior to the previously reported β-cyclodextrin. The quantification of acetylamantadine was not interfered with even a 50-fold amantadine and displayed no interference in artificial urine sample analysis, which indicates the good feasibility of this nanopore-based methodology in painless cancer prediagnosis. In addition, the discrimination mechanism is also explored by 2-D nuclear magnetic resonance (NMR) and nanopore experiments with a series of adamantane derivatives with different hydrophilic and hydrophobic groups. We found that both the hydrophobic region matching effect and hydrophilic interactions play a synergistic effect in forming a host–guest complex to further generate the characteristic signals, which may provide insights for the subsequent design and study of drug-cyclodextrin complexes.
研究领域:
生物化学
·
医学诊断
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROBIAL PATHOGENESIS
·
2024
·
IF 3.3
Peng Guo,Zhenye Li,Ting Cai,Du Guo,Baowei Yang,Chunling Zhang,Zhongguo Shan,Xin Wang,Xiaoli Peng,Guorong Liu,Chao Shi,Metab Alharbi,Abdullah F Alasmari
Listeria monocytogenes ( L. monocytogenes ) is a prevalent foodborne pathogen with a remarkable capacity to form biofilms on utensil surfaces. The Listeriolysin O (LLO) exhibits hemolytic activity, which is responsible for causing human infections. In this study, we investigated the inhibitory effect and mechanism of oregano essential oil (OEO) on L. monocytogenes , evaluated the effects on its biofilm removal and hemolytic activity. The minimum inhibitory concentration (MIC) of OEO against L. monocytogenes was 0.03 % ( v / v ). L. monocytogenes was treated with OEO at 3/2 MIC for 30 min the bacteria was decreased below the detection limit (10 CFU/mL) in PBS and TSB (the initial bacterial load was about 6.5 log CFU/mL). The level of L . monocytogenes in minced pork co-cultured with OEO (15 MIC) about 2.5 log CFU/g lower than that in the untreated group. The inhibitory mechanisms of OEO against planktonic L. monocytogenes encompassed perturbation of cellular morphology, elevation in reactive oxygen species levels, augmentation of lipid oxidation extent, hyperpolarization of membrane potential, and reduction in intracellular ATP concentration. In addition, OEO reduced biofilm coverage on the surface of glass slides by 62.03 % compared with the untreated group. Meanwhile, OEO (1/8 MIC) treatment reduced the hemolytic activity of L. monocytogenes to 24.6 % compared with the positive control. Molecular docking suggested carvacrol and thymol might reduce the hemolytic activity of L. monocytogenes . The results of this study demonstrate that OEO exhibits inhibitory effects against L. monocytogenes , biofilms and LLO, which had potential as natural antimicrobial for the inhibition of L. monocytogenes .
研究领域:
食品安全
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Foodborne Pathogens and Disease
·
2024
·
IF 1.9
Xu Xu,Pengfei Zhang,Fuqian Ruan,Guanhong Chang,Ting Zhou,DiShi Chen,Li Li,Xin Wang
Alpha-hemolysin (Hla) is a major virulence factor secreted by Staphylococcus aureus (S. aureus), which can lyse a variety of mammalian cells and help bacteria evade the host immune system or antibiotics, posing a safety hazard to human health. Therefore, it is critical to establish a quick-responsive and sensitive method for Hla detection to ensure food safety. In this work, a dual-mode immunoassay was developed with both colorimetric and fluorescent readouts for discriminative detection of Hla. The proposed sensing system consists of p-phenylenediamine (PPD) and fluorescein, where fluorescein functions as a fluorescent reporter, and PPD serves a dual function as a colorimetric reporter and fluorescence quencher. Subsequently, the reaction system of this method was optimized, and the detection limit, sensitivity, and specificity were evaluated. Under optimal conditions, the proposed method possesses excellent analytical performance in the range from 0.5 to 500 ng/mL with a limit of detection as low as 0.5 ng/mL. Noteworthy, this method was successfully employed for the detection of Hla in milk with good selectivity and high accuracy. Overall, the dual-mode immunoassay provides a superior platform for the on-site, quantitative, and accurate detection of Hla in food samples.
研究领域:
分析化学
·
食品科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Yaping Li,Yongqi Yang,Chunmeng Zhong,Dan Xiao,Cuisong Zhou
Sensitive detection of resistance mutation T790 M is of great significance for early diagnosis and prognostic monitoring of non-small-cell lung cancer (NSCLC). In this paper, we showed a highly sensitive detection strategy for T790 M using a three-level characteristic current signal pattern in an α-hemolysin nanopore. A probe was designed that formed a C–T mismatched base pair with wild-type/P and a T–T mismatched with the T790M/P. The T790M/P produced a unique three-level characteristic current signal in the presence of mercury ions(II): first, T790M–Hg2+–P entering the vestibule of α-HL under the transmembrane potential and overhang of probe occupying the β-barrel, then probe unzipping from the T790M/P, T790 M temporally residing inside the nanocavity due to the interaction with Hg(II), and finally T790 M passing through the β-barrel. The blocking current distribution was concentrated with a small relative standard deviation of about 3%, and the signal peaks of T790 M and wild-type can be completely separated with a high separation resolution of more than 2.5, which achieved the highly sensitive detection of T790 M down to 0.001 pM (confidence level P 95%) with a linear range from 0.001 pM to 1 nM in human serum samples. This highly sensitive recognition strategy enables the detection of low abundance T790 M and provides a method for prognostic monitoring in NSCLC patients.
研究领域:
生物物理学
·
医学诊断
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2023
·
IF 7.4
Ting Li,Wei Lu,Hui Tian,Yu Cao,Qianqian He,Xia Chen,Hailong Wang
The antitumor effect of Pt-based drugs is determined by their binding activity with deoxyribonucleic acid (DNA), and understanding the reaction process in a systematic manner is crucial. However, existing assays used for DNA–Pt research suffer from several issues, such as complicated sample preparation, preamplification, and expensive instruments, which dramatically limit their practical application. In this study, a novel method was presented to investigate the adducts of DNA and oxaliplatin using an α-hemolysin nanopore sensor. This approach allows for real-time monitoring of the DNA–oxaliplatin condensation process through the detection of nanopore events associated with DNA–oxaliplatin adducts. Specifically, type I and II signals exhibiting specific current characteristics were observed during the process. Typical signals with high frequency were obtained by recording the designed DNA sequence. Furthermore, the production of these signals was confirmed to be independent of homologous adducts. This finding suggests that the DNA–oxaliplatin adduct can serve as a potential sensor for detecting oxaliplatin lesions and multiple types of molecules.
研究领域:
生物物理学
·
纳米技术
·
癌症研究
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Chemistry Frontiers
·
2021
·Vol. 5
·期 18
·7032-7040
·
IF 6.482
Xiaojia Jiang,Mingsong Zang,Fei Li,Chunxi Hou,Quan Luo,Jiayun Xu,Junqiu Liu
Recently, biological nanopore-based techniques have attracted more and more attention in the field of single-molecule detection because they allow real-time, sensitive, high-throughput analysis. Herein, we report an engineered biological nanopore sensor by introducing a macrocyclic host molecule carboxylatopillar[5]arene (CP[5]A) that acts as an aptamer into the lumen of a mutant (E111R/K147R)7 αHL nanopore for detecting highly toxic paraquat (PQ) via host–guest interactions at the single-molecule level. By taking advantage of introducing positively charged arginine (Arg) into the lumen of the αHL nanopore, our engineered nanopore sensor exhibits higher stability. More importantly, this nanopore sensor shows high sensitivity, and the limit of detection (LOD) for PQ can reach a nanomolar level of 0.37 ppb. The CP[5]A-based nanopore sensing strategy developed in this work may bring inspiration for single-molecule detection and hold great potential in public health applications.
研究领域:
纳米技术
·
分析化学
·
生物技术
·
毒理学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Zhuoqun Su,Youlin Kong,Tong Li,Yan Zhao,Xue Zhang,Di Wu,Yongning Wu,Guoliang Li
Biological nanopore refers to a type of pore-forming membrane proteins, providing a unique platform for single molecule detection of DNA, RNA, peptide, etc. The direct detection of small molecules, especially of food chemical contaminants by biological nanopore, remains challenging due to their fast translocation dynamics, trace amount, and the interference from the complex food matrix. The effective recognition and signal conversion methods need to be developed. Herein, we employ an aptamer-triggered hybridization chain reaction (AtHCR) strategy for the detection of a mycotoxin, aflatoxin B1 (AFB1) by an α -hemolysin nanopore. In the absence of AFB1, the formed dsDNA polymers in HCR show a low frequency of long-time blockage signals. The presence of AFB1 can inhibit the hybridization chain reaction through the interaction between AFB1 and its aptamer, so the remaining hairpins can easily block the nanopore and induce frequent long-time blockage signals. The results show that the event frequency of long-blockage has a linear relationship with the AFB1 concentration in the range of 6.6 × 10 −1 –6.6 × 10 2 pmol/L. The recognition and amplification effect of AtHCR allows nanopore to detect AFB1 at a detection limit of 0.54 pmol/L. Furthermore, the developed AtHCR strategy can help biological nanopore to detect AFB1 in corn sample with satisfactory accuracy. The recognition and amplification effect achieved by coupling AtHCR to biological nanopore offers an enzyme-free single-molecule technology for the rapid detection of food chemical contaminants.
研究领域:
纳米技术
·
分析化学
·
食品安全
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）