Hemin/G-Quadruplex Horseradish Peroxidase-Mimicking DNAzyme: Principle and Biosensing Application

2017 ◽  
pp. 85-106 ◽  
Author(s):  
Negar Alizadeh ◽  
Abdollah Salimi ◽  
Rahman Hallaj
Keyword(s):  
Horseradish Peroxidase ◽  
G Quadruplex

Metalloporphyrin/G-quadruplexes: From basic properties to practical applications

2015 ◽  
Vol 19 (01-03) ◽  
pp. 65-91 ◽  
Author(s):  
Eyal Golub ◽  
Chun-Hua Lu ◽  
Itamar Willner
Keyword(s):  
Quantum Dots ◽  
Horseradish Peroxidase ◽  
Protoporphyrin Ix ◽  
Semiconductor Quantum Dots ◽  
Fluorescence Properties ◽  
Chemical Transformations ◽  
Fluorescence Sensing ◽  
Practical Applications ◽  
Sensing Platforms ◽  
G Quadruplex

Guanine-rich single-stranded nucleic acids self-assemble into G-quadruplex nanostructures (predominately in the presence of K +-ions). Metalloporphyrins bind to the G-quadruplex nanostructures to form supramolecular assemblies exhibiting unique catalytic, electrocatalytic and photophysical properties. This paper addresses the advances in the characterization and the implementation of the metalloporphyrin/G-quadruplexes complexes for various applications. Out of the different complexes, the most extensively studied complexes are the hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme and the Zn(II) -protoporphyrin IX-functionalized G-quadruplex. Specifically, the hemin/G-quadruplex was found to act as a catalyst for driving different chemical transformations that mimic the native horseradish peroxidase enzyme, and, also, to function as an electrocatalyst for the reduction of H 2 O 2. Also, the hemin/G-quadruplex stimulates interesting photophysical and photocatalytic processes such as the electron-transfer quenching of semiconductor quantum dots or the chemiluminescence resonance energy transfer to semiconductor quantum dots. Alternatively, Zn(II) -protoporphyrin IX associated with G-quadruplexes exhibit intensified fluorescence properties. Beyond the straight forward application of the metalloporphyrin/G-quadruplexes as catalysts that stimulate different chemical transformations, the specific catalytic, electrocatalytic and photocatalytic functions of hemin/G-quadruplexes are heavily implemented to develop sophisticated colorimetric, electrochemical, and optical sensing platforms. Also, the unique fluorescence properties of Zn(II) -protoporphyrin IX-functionalized G-quadruplexes are applied to develop fluorescence sensing platforms. The article exemplifies different sensing assays for analyzing DNA, ligand-aptamer complexes and telomerase activity using the metalloporphyrins/G-quadruplexes as transducing labels. Also, the use of the hemin/G-quadruplex as a probe to follow the operations of DNA machines is discussed.

Detection of breast cancer-derived exosomes using the horseradish peroxidase-mimicking DNAzyme as an aptasensor

The Analyst ◽  
2020 ◽  
Vol 145 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Yu Zhou ◽  
Huiying Xu ◽  
Hua Wang ◽  
Bang-Ce Ye
Keyword(s):  
Breast Cancer ◽  
Horseradish Peroxidase ◽  
G Quadruplex ◽  
Muc1 Aptamer

A hairpin-like aptasensor combining the specific MUC1 aptamer with a hemin/G-quadruplex is developed for the detection of breast cancer exosomes.

Colorimetric Detection of Copper(II) Ion Using Click Chemistry and Hemin/G-Quadruplex Horseradish Peroxidase-Mimicking DNAzyme

2014 ◽  
Vol 86 (13) ◽  
pp. 6387-6392 ◽  
Author(s):  
Chenchen Ge ◽  
Quan Luo ◽  
Dou Wang ◽  
Shiming Zhao ◽  
Xiaoling Liang ◽  
...  
Keyword(s):  
Horseradish Peroxidase ◽  
Click Chemistry ◽  
Colorimetric Detection ◽  
G Quadruplex

Effects of Vincristine on Endothelial Microtubules in the Spinal Cord

1976 ◽  
Vol 34 ◽  
pp. 58-59
Author(s):  
John L. Beggs ◽  
John D. Waggener ◽  
Wanda Miller
Keyword(s):  
Spinal Cord ◽  
Biological Activity ◽  
Horseradish Peroxidase ◽  
Transport Mechanism ◽  
Vasogenic Edema ◽  
Vesicular Transport ◽  
Close Proximity

Microtubules (MT) are versatile organelles participating in a wide variety of biological activity. MT involvement in the movement and transport of cytoplasmic components has been well documented. In the course of our study on trauma-induced vasogenic edema in the spinal cord we have concluded that endothelial vesicles contribute to the edema process. Using horseradish peroxidase as a vascular tracer, labeled endothelial vesicles were present in all situations expected if a vesicular transport mechanism was in operation. Frequently,labeled vesicles coalesced to form channels that appeared to traverse the endothelium. The presence of MT in close proximity to labeled vesicles sugg ested that MT may play a role in vesicular activity.

Comparative strengths and weaknesses of peroxidase and colloidal gold in pre- and post-embedding immunolabeling techniques

1987 ◽  
Vol 45 ◽  
pp. 1002-1005
Author(s):  
D. R. Abrahamson ◽  
P. L. St.John ◽  
E. W. Perry
Keyword(s):  
Electron Microscopy ◽  
Horseradish Peroxidase ◽  
Light Microscopy ◽  
Colloidal Gold ◽  
Light Microscope ◽  
Ultrastructural Localization ◽  
The Other ◽  
Quantitative Studies ◽  
Dense Suspension ◽  
Antigen Localization

Antibodies coupled to tracers for electron microscopy have been instrumental in the ultrastructural localization of antigens within cells and tissues. Among the most popular tracers are horseradish peroxidase (HRP), an enzyme that yields an osmiophilic reaction product, and colloidal gold, an electron dense suspension of particles. Some advantages of IgG-HRP conjugates are that they are readily synthesized, relatively small, and the immunolabeling obtained in a given experiment can be evaluated in the light microscope. In contrast, colloidal gold conjugates are available in different size ranges and multiple labeling as well as quantitative studies can therefore be undertaken through particle counting. On the other hand, gold conjugates are generally larger than those of HRP but usually can not be visualized with light microscopy. Concern has been raised, however, that HRP reaction product, which is exquisitely sensitive when generated properly, may in some cases distribute to sites distant from the original binding of the conjugate and therefore result in spurious antigen localization.

Unlabeled Antibody Immunocytochemistry Applied to Murine Mammary Tumor Cells

1975 ◽  
Vol 33 ◽  
pp. 390-391
Author(s):  
Wm. J. Arnold ◽  
J. Russo ◽  
H. D. Soule ◽  
M. A. Rich
Keyword(s):  
Horseradish Peroxidase ◽  
Mammary Tumor ◽  
Covalent Binding ◽  
Petri Dish ◽  
Gamma Chain ◽  
Mammary Tumor Virus ◽  
Mammary Tumor Cells ◽  
Murine Mammary Tumor ◽  
Tumor Virus ◽  
Unlabeled Antibody

Our studies of mammary tumor virus have included the application of the unlabeled antibody enzyme method of Sternberger to mammary tumor derived mouse cells in culture and observation with an electron microscope. The method avoids the extravagance of covalent binding of indicator molecules (horseradish peroxidase) with precious antibody locator molecules by relying instead upon specific antibody-antigen linkages. Our reagents included: Primary Antibody, rabbit anti-murine mammary tumor virus (MuMTV) which was antiserum 113 AV-2; Secondary Antibody, goat anti-rabbit IgG gamma chain (Cappel Laboratories); andthe Indicator, rabbit anti-horseradish peroxidase - horseradish peroxidase complex (PAP) (Cappel Labs.). Dilutions and washes were made in 0.05 M Tris 0.15 M saline buffered to pH 7.4. Cell monolayers, after light fixation in glutaraldehyde, were incubated in place by a protocol adapted from Sternberger and Graham and Karnovsky, then embedded by our usual method for monolayers. Reagents were confined to specific areas by neoprene 0-rings (Parker Seal Co.) reducing the amount of reagent needed to 50 microliters, 1/6th of that required to wet a 35 mm petri dish.

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