PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2012
·Vol. 14
·期 47
·16258-16266
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IF 3.573
Yonghai Song,Dan Luo,Shuhong Ye,Mei Huang,Dandan Zhong,Zhenzhong Huang,Haoqing Hou,Li Wang
Water-soluble fluorescent quantum dots (QDs) have been widely used in biological and biomedical fields, and the interaction between QDs and proteins and the conformational structure of the protein in the bioconjugate has attracted increasing attention. In this study, UV-Vis spectroscopy, fluorescence quenching, CD spectra, gel electrophoresis and Fourier transform infrared (FTIR) spectroscopic techniques were used to systematically investigate the interaction between type II restriction endonuclease (EcoRI) and CdS QDs and the conformational structure of EcoRI in the EcoRI-CdS QDs bioconjugates. The results indicated that electrostatic interactions played a major role in the binding reaction at pH 6.0, and the nature of quenching was static, resulting in forming CdS QDs–EcoRI bioconjugates. FTIR and CD spectra studies indicated a decrease of α-helical and turn structures accompanied by the increase of β-sheet structures of EcoRI in the bioconjugates. This study showed that the interaction between EcoRI and CdS QDs resulted in a change in the secondary structure of EcoRI after it was conjugated with CdS QDs, but the enzyme activity was maintained.
研究领域:
生物物理
·
生物化学
·
纳米生物技术
·
分子生物学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2013
·
IF 3.554
Yonghai Song,Dandan Zhong,Dan Luo,Mei Huang,Zhenzhong Huang,Hongliang Tan,Lanlan Sun,Li Wang
Better understanding of the interaction between nanoparticles (NPs) and protein is the basis for biological and biomedical applications of NPs. Water-soluble fluorescent CdS NPs have been widely used in the biological and biomedical fields and the study on effect of CdS NPs size on conformation and enzymatic activity of protein might be very important in its application. In this work, the interaction of CdS NPs with different size with type II restriction endonuclease (EcoRI) were investigated by atomic force microscopy, transmission electron microscopy, UV–vis spectroscopy, fluorescence quenching method, CD spectra, laser scanning confocal microscopy and gel electrophoresis. It was found that the equilibrium constant ( k D ) as well as the cooperativity degree of CdS NPs-EcoRI binding (Hill constant, n ) strongly depended on the CdS NPs size. The different curvature of CdS NPs surface could result in different changes of EcoRI conformation. The gel electrophoresis indicated that the decrease in α-helix content more or less affected the activity of EcoRI.
研究领域:
纳米技术
·
生物化学
·
分子生物学
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2014
·
IF 2.354
Yonghai Song,Mei Huang,Dan Luo,Dandan Zhong,Haoqing Hou,Fugang Xu
In this study, we investigated the interaction between EcoRI and CdS QDs modified with different functional groups as well as the conformational changes of EcoRI in the process. MUD capped (CdS–OH QDs) and UDT capped (CdS–CH 3 QDs) CdS QDs were separately prepared and used to react with EcoRI, respectively. The interaction was characterized by various spectroscopic techniques including UV–vis absorption, fluorescence and Fourier transform infrared (FTIR) spectroscopy, together with electrophoresis methods. The strength of interaction for EcoRI with CdS–OH QDs and CdS–CH 3 QDs was evaluated and analysed. Relevant thermodynamic parameters such as Δ H , Δ G and Δ S were calculated and a static quenching interaction process was proposed. The conformational change of EcoRI interacted with CdS–OH QDs or CdS–CH 3 QDs was also measured and compared. Finally agarose electrophoresis assay was performed and revealed that the enzyme activity of EcoRI was somewhat conserved after interaction with CdS QDs. This study contributed to a better understanding of protein-NPs interaction and created a framework for applications of nanomaterial-biomolecule conjugation in some fields such as nanobiology and nanomedicine.
研究领域:
纳米生物技术
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生物化学
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分子生物学
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纳米医学
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产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2016
·
IF 7.476
Yingjie Li,Yuqin Li,Yaoyu Wu,Fushen Lu,Yaowen Chen,Wenhua Gao
Endonucleases cleavage of DNA plays an important role in biological and medicinal chemistry . This work was going to develop a reliable and sensitive electrochemiluminescent (ECL) biosensor for detecting endonucleases by using gold nanoparticles graphene composite (GNPs-graphene) as a signal amplifier. Firstly, the GNPs and graphene were simultaneously deposited on the glassy carbon electrode (GCE) by cyclic voltammetry . Then a stem DNA was anchored on the surface of GCE. And with a modifying DNA introduced into the electrode by DNA assembly, a strong ECL signal was obtained. After a DNA modified with ferrocene assembly to the stem DNA, the ECL signal had a sharp decrease due to the quench effect of ferrocene to and the biosensor comes into being a “off” state. With the effect of endonuclease, the ECL signal had a recovery because of the ferrocene being released and the biosensor formed a “on” state. Moreover, the recovery of ECL signal was related to the concentration of endonucleases. Combining specific defined DNA and endonuclease, this method has a potential to detect different endonucleases. In this work, we took the EcoRI as an example to identify the feasibility of ECL biosensor in applying in sensitive detection of endonucleases using a GNPs-graphene signal amplifier. Under optimal condition, the proposed biosensor obtained a low limit of detection (LOD) 5.6×10 −5 U mL −1 . And the stability, selectivity and reproducibility of the biosensor also were researched.
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DOI
PubMed
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 45
·28008-28013
·
IF 3.361
Congcong Gao,Baoquan Che,Hong Dai
EcoRI is an important biomacromolecule in live cells and protects bacterial cells against foreign DNA. In this work, we developed a simple and convenient G-triplex (G3) (5′-TGGGAAGGGAGGGAATTCCCT-3′)-based colorimetric assay for the rapid and selective detection of EcoRI activity and inhibition. The sequence specifically responds to EcoRI in the presence of K+ and hemin to form a G-triplex/hemin complex. Taking advantage of G-triplex, EcoRI activity was investigated under the optimized conditions. The absorption intensity ratio displayed a linear relationship against the concentration of EcoRI in the range 0 to 100 U mL−1, and the detection limit was 5.7 U mL−1. Furthermore, G3 showed good selectivity, and the ability to be used to screen for EcoRI inhibitors, indicating its potential in detection and analysis applications.
研究领域:
分子生物学
·
生物化学
·
分析化学
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DOI
PubMed
高影响因子
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