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Abstract
Nanozymes have the potential to replace natural enzymes, so they are widely used in energy conversion technologies such as biosensors and signal transduction (converting biological signals of a target into optical, electrical, or metabolic signals). The participation of nucleic acids leads nanozymes to produce richer interface effects and gives energy conversion events more attractive characteristics, creating what are called “functional nanozymes”. Since different nanozymes have different internal structures and external morphological characteristics, functional modulation needs to be compatible with these properties, and attention needs to be paid to the influence of nucleic acids on nanozyme activity. In this review, “functional nanozymes” are divided into three categories, (nanozyme precursor ion)/ (nucleic acid) self-assembly, nanozyme-nucleic acid irreversible binding, and nanozyme-nucleic acid reversible binding, and the effects of nucleic acids on modulation principles are summarized. Then, the latest developments of nucleic acid-modulated nanozymes are reviewed in terms of their use in energy conversion technology, and their conversion mechanisms are critically discussed. Finally, we outline the advantages and limitations of “functional nanozymes” and discuss the future development prospects and challenges in this field.
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Label-free fluorescent and electrochemical biosensors based on defective G-quadruplexes. Biosens Bioelectron 2018; 118:1-8. [DOI: 10.1016/j.bios.2018.07.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 12/14/2022]
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Cai N, Tan L, Li Y, Xia T, Hu T, Su X. Biosensing platform for the detection of uric acid based on graphene quantum dots and G-quadruplex/hemin DNAzyme. Anal Chim Acta 2017; 965:96-102. [DOI: 10.1016/j.aca.2017.01.067] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/27/2017] [Accepted: 01/31/2017] [Indexed: 12/22/2022]
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Cai N, Li Y, Chen S, Su X. A fluorometric assay platform for caffeic acid detection based on the G-quadruplex/hemin DNAzyme. Analyst 2016; 141:4456-62. [DOI: 10.1039/c6an00543h] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A fluorometric assay platform based on GQDs is designed for biochemical detection of caffeic acid.
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Affiliation(s)
- Nan Cai
- Department of Analytical Chemistry
- College of Chemistry
- Jilin University
- Changchun 130012
- P.R. China
| | - Yan Li
- Department of Analytical Chemistry
- College of Chemistry
- Jilin University
- Changchun 130012
- P.R. China
| | - Shufan Chen
- Department of Analytical Chemistry
- College of Chemistry
- Jilin University
- Changchun 130012
- P.R. China
| | - Xingguang Su
- Department of Analytical Chemistry
- College of Chemistry
- Jilin University
- Changchun 130012
- P.R. China
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Wang G, Chen L, Zhu Y, Wang L, Zhang X. Adenosine Triphosphate Sensing by Electrocatalysis with DNAzyme. ELECTROANAL 2013. [DOI: 10.1002/elan.201300425] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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6
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Dong XY, Mi XN, Zhang L, Liang TM, Xu JJ, Chen HY. DNAzyme-functionalized Pt nanoparticles/carbon nanotubes for amplified sandwich electrochemical DNA analysis. Biosens Bioelectron 2012; 38:337-41. [DOI: 10.1016/j.bios.2012.06.015] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 06/11/2012] [Accepted: 06/12/2012] [Indexed: 12/14/2022]
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Zhang Y, Li B, Jin Y. Label-free fluorescent detection of thrombin using G-quadruplex-based DNAzyme as sensing platform. Analyst 2011; 136:3268-73. [PMID: 21725571 DOI: 10.1039/c1an00002k] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report herein a label-free and sensitive fluorescent method for detection of thrombin using a G-quadruplex-based DNAzyme as the sensing platform. The thrombin-binding aptamer (TBA) is able to bind hemin to form the G-quadruplex-based DNAzyme, and thrombin can significantly enhance the activity of the G-quadruplex-based DNAzyme. The G-quadruplex-based DNAzyme is found to effectively catalyze the H(2)O(2)-mediated oxidation of thiamine, giving rise to fluorescence emission. This allows us to utilize the H(2)O(2)-thiamine fluorescent system for the quantitative analysis of thrombin. The assay shows a linear toward thrombin concentration in the range of 0.01-0.12 nM. The present limit of detection for thrombin is 1 pM, and the sensitivity for analyzing thrombin is improved by about 10,000-fold as compared with the reported colorimetric counterpart. The work also demonstrates that thiamine is an excellent substrate for the fluorescence assay using the G-quadruplex-based DNAzyme as the sensing platform.
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Affiliation(s)
- Yuanfu Zhang
- Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an, 710062, PR China
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Zhang J, Gao Q, Chen P, Chen J, Chen G, Fu F. A novel Tb3+-promoted G-quadruplex-hemin DNAzyme for the development of label-free visual biosensors. Biosens Bioelectron 2011; 26:4053-7. [DOI: 10.1016/j.bios.2011.03.029] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2010] [Revised: 03/20/2011] [Accepted: 03/27/2011] [Indexed: 11/29/2022]
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Li CL, Liu KT, Lin YW, Chang HT. Fluorescence detection of lead(II) ions through their induced catalytic activity of DNAzymes. Anal Chem 2010; 83:225-30. [PMID: 21141923 DOI: 10.1021/ac1028787] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We have developed a fluorescence approach for the highly selective and sensitive detection of Pb(2+) ions using AGRO100, a G-quadruplex DNAzyme. The sensing strategy is based on Pb(2+) ions inducing increased DNAzyme activity of AGRO100 in the presence of hemin, which acts as a cofactor to catalyze H(2)O(2)-mediated oxidation of Amplex UltraRed (AUR). A test of eight aptamers of various sequences for the detection of Pb(2+) ions revealed that AGRO100 performed the best in terms of sensitivity. The AGRO100-AUR probe exhibited high selectivity (>100-fold) toward Pb(2+) ions over other tested metal ions. The fluorescence intensity (excitation/emission maxima, ca. 561/592 nm) of the AUR product was proportional to the concentration of Pb(2+) ions over the range 0-1000 nM, with a linear correlation (R(2) = 0.98). For 5 mM Tris-acetate (pH 7.4) solutions in the presence and absence of 100 mM NaCl, the AGRO100-AUR probe provided limits of detection (signal-to-noise ratio = 3) for Pb(2+) ions of 1.0 and 0.4 nM, respectively. We validated the practicality of the use of the AGRO100-AUR probe for the determination of the concentrations of Pb(2+) ions in soil samples. This approach allows the determination of the concentrations of Pb(2+) ions with simplicity, selectivity, and sensitivity.
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Affiliation(s)
- Chi-Lin Li
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
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Kong DM, Cai LL, Shen HX. Quantitative detection of Ag(+) and cysteine using G-quadruplex-hemin DNAzymes. Analyst 2010; 135:1253-8. [PMID: 20390219 DOI: 10.1039/b925168e] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A highly sensitive and selective Ag(+) detection method was developed based on the Ag(+)-mediated formation of G-quadruplex-hemin DNAzymes. In this method, two unlabelled oligonucleotides with different lengths are used. In the absence of Ag(+), the two oligonucleotides hybridize to each other to form an intermolecular duplex. The addition of Ag(+) can disrupt the intermolecular duplex and promote a part of the sequence of the longer oligonucleotide to fold into an intramolecular duplex, in which cytosine-cytosine (C-C) mismatches are stabilized by C-Ag(+)-C base pairs. As a result, the G-rich sequence of the same oligonucleotide can fold into a G-quadruplex, which is able to bind hemin to form a catalytically active G-quadruplex-hemin DNAzyme. This can be reflected by an absorbance increase when monitored in the H(2)O(2)-ABTS (2,2'-azinobis(3-ethylbenzothiozoline)-6-sulfonic acid) reaction system by using UV-vis absorption spectroscopy. This 'turn-on' process allows the detection of aqueous Ag(+) at concentrations as low as 20 nM using a simple colorimetric technique. Considering that Cysteine (Cys) is a strong binder of Ag(+), the presence of Cys may disrupt the C-Ag(+)-C base pairs in the intramolecular duplex, resulting in the reformation of the intermolecular duplex and the decrease of the catalytic activity of the sensing system. Therefore, the Ag(+)-sensing system can be further developed as a Cys-sensing system. This method allows the detection of Cys with a detection limit of 25 nM. With the development of the studies on DNA-metal base pairs, this Ag(+)-sensing method can be easily extended to the analysis of other metal ions.
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Affiliation(s)
- De-Ming Kong
- Key Laboratory of Functional Polymer Materials, Ministry of Education, Nankai University, Tianjin, 300071, People's Republic of China.
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Higuchi A, Yang ST, Siao YD, Hsieh PV, Fukushima H, Chang Y, Chen WY. Peroxidase activity of DNA aptamer-pt complexes prepared with cisplatin. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2010; 21:67-82. [PMID: 20040154 DOI: 10.1163/156856209x410238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DNA aptamers carrying Pt nanoparticles prepared with cisplatin showed peroxidase enzymatic activity while retaining the specific binding ability of the aptamers. Optimal preparation conditions of DNA-Pt complex prepared with cisplatin were investigated on the synthesis at pH 7-11, a reaction time of 1-18 h and 90 degrees C. The enzymatic reaction of DNA-Pt complex obeyed Michaelis-Menten kinetics. K(M) for the DNA-Pt complex was found to be of the same order as K(M) for hemin and hemin-DNA complex, but one order of magnitude higher than that of horseradish peroxidase. A sandwich type of DNA enzyme-linked aptamer assay (DLAA) using DNA-Pt complex successively detected target protein of thrombin. DLAA using DNA-Pt complex fractioned by ultrafiltration membranes having a molecular weight cut-off of 30 000 and 300 000 showed 1.9-times higher sensitivity than DLAA using DNA-Pt complex without fraction. The DNA-Pt complex having specific size was effective for the sensitive detection of thrombin in DLAA.
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Affiliation(s)
- Akon Higuchi
- Department of Chemical and Materials Engineering, National Central University, 300 Jhongda Road, Jhongli, Taoyuan 32001, Taiwan.
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Wang J, Cao Y, Chen G, Li G. Regulation of thrombin activity with a bifunctional aptamer and hemin: development of a new anticoagulant and antidote pair. Chembiochem 2009; 10:2171-6. [PMID: 19650102 DOI: 10.1002/cbic.200900408] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jing Wang
- Department of Biochemistry and National Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210093, China
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Kong DM, Yang W, Wu J, Li CX, Shen HX. Structure-function study of peroxidase-like G-quadruplex-hemin complexes. Analyst 2009; 135:321-6. [PMID: 20098765 DOI: 10.1039/b920293e] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure-function relationship of G-quadruplex-hemin complexes with peroxidase activity was studied by comparing peroxidase activity and circular dichroism (CD) spectra of 22 oligonucleotides with the sequence of d(G(2)T(n))(3)G(2), d(G(3)T(n))(3)G(3) (n = 1-4) and dG(3)T(i)G(3)T(j)G(3)T(k)G(3). According to the experimental results, some conclusions can be drawn, such as the addition of hemin may promote the conversion of some G-quadruplexes from antiparallel structures to parallel structures; the formation of G-quadruplexes is a crucial factor in determining the peroxidase activity of G-quadruplex-hemin complexes; and the complexes formed by hemin and parallel G-quadruplexes have much higher peroxidase activity than those formed by hemin and antiparallel G-quadruplexes.
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Affiliation(s)
- De-Ming Kong
- Key Laboratory of Functional Polymer Materials, Ministry of Education, Nankai University, Tianjin, 300071, People's Republic of China.
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Chemiluminescence flow biosensor for hydrogen peroxide using DNAzyme immobilized on eggshell membrane as a thermally stable biocatalyst. Biosens Bioelectron 2009; 24:2534-40. [DOI: 10.1016/j.bios.2009.01.010] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2008] [Revised: 12/30/2008] [Accepted: 01/05/2009] [Indexed: 11/17/2022]
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Liu M, Kagahara T, Abe H, Ito Y. In vitro selection of hemin-binding catalytic RNA. Bioorg Med Chem Lett 2009; 19:1484-7. [DOI: 10.1016/j.bmcl.2009.01.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 12/25/2008] [Accepted: 01/08/2009] [Indexed: 12/14/2022]
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Higuchi A, Yang ST, Siao YD, Hsieh PV, Fukushima H, Chang Y, Chen WY. Preparation of fractioned DNA aptamer–Pt complex through ultrafiltration and the colorimetric sensing of thrombin. J Memb Sci 2009. [DOI: 10.1016/j.memsci.2008.11.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Higuchi A, Siao YD, Yang ST, Hsieh PV, Fukushima H, Chang Y, Ruaan RC, Chen WY. Preparation of a DNA aptamer-Pt complex and its use in the colorimetric sensing of thrombin and anti-thrombin antibodies. Anal Chem 2008; 80:6580-6. [PMID: 18665606 DOI: 10.1021/ac8006957] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DNA aptamers carrying Pt nanoparticles were prepared by the reaction of DNA aptamers (without functionalization with biotin, thiol, or other reactive groups) with K 2[PtCl 4] in solution at 60-90 degrees C. The DNA-Pt complexes possessed peroxidase enzymatic activity while retaining the specific binding ability of the aptamers. The enzymatic reaction of these complexes obeyed Michaelis-Menten kinetics. K M for the DNA-Pt complex was found to be on the same order as K M for hemin and hemin-DNA complex but 1 or 2 orders of magnitude higher than that of horseradish peroxidase. The rate of the reaction catalyzed by the DNA-Pt complex, k cat, was found to be on the same order as that of hemin and hemin-DNA complex but 2 or 3 orders of magnitude lower than that of horseradish peroxidase. Two types of DNAzyme-linked aptamer assays (DLAAs) were developed using these complexes, which successfully detected target proteins, with the sandwich type of DLAA targeting thrombin and the competitive type of DLAA targeting anti-thrombin IgA/G/M in serum. The DNA-Pt complexes retained their peroxidase enzymatic activity even after heat treatment. DLAAs having high thermal stability were developed using these complexes, which were free of animal and plant matter because neither antibodies nor horseradish peroxidase were used in their synthesis.
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Affiliation(s)
- Akon Higuchi
- Department of Chemical and Materials Engineering, National Central University, Jhongli, Taoyuan, 32001 Taiwan.
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Enzymatic activity of immobilized enzyme determined by isothermal titration calorimetry. Anal Biochem 2008; 378:184-9. [DOI: 10.1016/j.ab.2008.04.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 04/03/2008] [Accepted: 04/05/2008] [Indexed: 11/19/2022]
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Matsuoka Y, Onodera T, Kojima T, Chang Y, Chen WY, Imanaka T, Fukushima H, Higuchi A. Novel Enzymatic Properties of DNA−Pt Complexes. Biomacromolecules 2007; 8:2684-8. [PMID: 17676798 DOI: 10.1021/bm070137i] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DNA-Pt complexes have shown novel enzymatic activity as a peroxidase similar to that of horseradish peroxidase in the colorimetric reaction with its substrate. The enzymatic activity of these complexes increased with increasing reaction time and pH in reaction solutions of DNA and K2[PtCl4]. This enhanced enzymatic activity was attributed to the increase in Pt conjugated to DNA in the complex. The enzymatic activity per unit mole of the DNA-Pt complex was significantly higher for complexes prepared with high molecular weight DNA because the enzymatic activity of the complex per repeat unit of DNA was almost constant for these complexes prepared under the same reaction conditions. All the DNA-Pt complexes in this study prepared with different DNA sequences (i.e., [A]20, [G]20, [C]20, [T]20, and [AG]10) exhibited peroxidase enzymatic activity. These complexes showed good thermal stability as compared to native horseradish peroxidase.
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Affiliation(s)
- Yuki Matsuoka
- Department of Materials and Life Science, Seikei University, 3-3-1 Kichijoji Kitamachi, Musashino, Tokyo 180-8633, Japan
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Li T, Li B, Dong S. Aptamer-based label-free method for hemin recognition and DNA assay by capillary electrophoresis with chemiluminescence detection. Anal Bioanal Chem 2007; 389:887-93. [PMID: 17641877 DOI: 10.1007/s00216-007-1487-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 06/28/2007] [Accepted: 06/29/2007] [Indexed: 11/29/2022]
Abstract
An aptamer-based label-free approach to hemin recognition and DNA assay using capillary electrophoresis with chemiluminescence detection is introduced here. Two guanine-rich DNA aptamers were used as the recognition element and target DNA, respectively. In the presence of potassium ions, the two aptamers folded into the G-quartet structures, binding hemin with high specificity and affinity. Based on the G-quartet-hemin interactions, the ligand molecule was specifically recognized with a Kd approximately 73 nM, and the target DNA could be detected at 0.1 microM. In phosphate buffer of pH 11.0, hemin catalyzed the H2O2-mediated oxidation of luminol to generate strong chemiluminescence signal; thus the target molecule itself served as an indicator for the molecule-aptamer interaction, which made the labeling and/or modification of aptamers or target molecules unnecessary. This label-free method for molecular recognition and DNA detection is therefore simple, easy, and effective.
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Affiliation(s)
- Tao Li
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China
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Wang ZG, Ke BB, Xu ZK. Covalent immobilization of redox enzyme on electrospun nonwoven poly(acrylonitrile-co-acrylic acid) nanofiber mesh filled with carbon nanotubes: A comprehensive study. Biotechnol Bioeng 2006; 97:708-20. [PMID: 17171660 DOI: 10.1002/bit.21280] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In this work, novel conductive composite nanofiber mesh possessing reactive groups was electrospun from solutions containing poly(acrylonitrile-co-acrylic acid) (PANCAA) and multi-walled carbon nanotubes (MWCNTs) for redoxase immobilization, assuming that the incorporated MWCNTs could behave as electrons transferor during enzyme catalysis. The covalent immobilization of catalase from bovine liver on the neat PANCAA nanofiber mesh or the composite one was processed in the presence of EDC/NHS. Results indicated that both the amount and activity retention of bound catalase on the composite nanofiber mesh were higher than those on the neat PANCAA nanofiber mesh, and the activity increased up to 42%. Kinetic parameters, K(m) and V(max), for the catalases immobilized on the composite nanofiber mesh were lower and higher than those on the neat one, respectively. This enhanced activity might be ascribed to either promoted electron transfer through charge-transfer complexes and the pi system of carbon nanotubes or rendered biocompatibility by modified MWCNTs. Furthermore, the immobilized catalases revealed much more stability after MWCNTs were incorporated into the polymer nanofiber mesh. However, there was no significant difference in optimum pH value and temperature, thermal stability and operational stability between these two immobilized preparations, while the two ones appeared more advantageous than the free in these properties. The effect of MWCNTs incorporation on another redox enzyme, peroxidase, was also studied and it was found that the activity increased by 68% in comparison of composite one with neat preparation.
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Affiliation(s)
- Zhen-Gang Wang
- Institute of Polymer Science, and Key Laboratory of Macromolecular Synthesis and Functionalization (Ministry of Education), Zhejiang University, Hangzhou 310027, PR China
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Travascio P, Sen D, Bennet AJ. DNA and RNA enzymes with peroxidase activity An investigation into the mechanism of action. CAN J CHEM 2006. [DOI: 10.1139/v06-057] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A DNAhemin complex (PS2.Mhemin), and its RNA counterpart (rPS2.Mhemin), have previously been reported, in the presence of nitrogenous buffers such as HEPES, to show enhanced peroxidative activity relative to both uncomplexed hemin and a control DNAhemin complex (Chem. Biol. 5, 505, 1998). A kinetic analysis of these two hemin-utilizing nucleic acid enzymes provides key insights into the mechanisms for their catalyzed peroxidation reactions. First, control experiments indicate that charge on the added detergent, required for solubility reasons, has little effect on the efficiency of the nucleic-acid-catalyzed reactions. Second, the key functional impact of the two nucleic acid frameworks, either DNA or RNA, appears to be a reduction in the acidity of a water molecule coordinated to the iron atom of the hemin that is bound to the ribozyme and DNAzyme scaffolds. This effect could result from a polar environment and possibly hydrogen bond(s) at the axial position of the hemin, along with favourable hydrophobic interactions for the periphery of the porphyrin ring. Third, the basic component of the buffer enhances the activities; this likely results from a general-base-catalyzed process. Cumulatively, these data supply important clues as to how biopolymers other than a protein can complex with hemin to form productive peroxidase enzymes.Key words: ribozyme, DNAzyme, hemin, peroxidase, mechanism, guanine quadruplex.
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Special-Purpose Modifications and Immobilized Functional Nucleic Acids for Biomolecular Interactions. Top Curr Chem (Cham) 2005. [DOI: 10.1007/b136673] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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