Fingerprinting branches on supercoiled plasmid DNA using quartz nanocapillaries

Nanoscale ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 320-331
Author(s):  
Sumanth Kumar Maheshwaram ◽  
Koushik Sreenivasa ◽  
Gautam Vivek Soni
Keyword(s):  
Quantitative Analysis ◽  
Plasmid Dna ◽  
Structural Changes ◽  
Supercoiled Dna ◽  
Detailed Understanding ◽  
Supercoiled Plasmid

We show detailed understanding of enzyme dependent structural changes in supercoiled DNA along with a quantitative analysis of its branches using nanopores.

Quantitative Analysis of Micro-structural Changes in a Bituminous Coal After Exposure to Supercritical CO2 and Water

2019 ◽  
Vol 28 (4) ◽  
pp. 1639-1660 ◽  
Author(s):  
Guanglei Zhang ◽  
P. G. Ranjith ◽  
M. S. A. Perera ◽  
Yiyu Lu ◽  
Xavier Choi
Keyword(s):  
Quantitative Analysis ◽  
Supercritical Co2 ◽  
Bituminous Coal ◽  
Structural Changes

Adenovirus 2 peptide IX gene is expressed only on replicated DNA molecules

1986 ◽  
Vol 6 (12) ◽  
pp. 4149-4154
Author(s):  
T Matsui ◽  
M Murayama ◽  
T Mita
Keyword(s):  
Quantitative Analysis ◽  
Cytosine Arabinoside ◽  
Plasmid Dna ◽  
Adenovirus Type ◽  
Plasmid Replication ◽  
Gene Transcript ◽  
Dna Molecules ◽  
Transfected Cells ◽  
Active Transcription

Transcription of the adenovirus type 2 peptide IX (pIX) gene was examined in transient expression assays. When a nonreplicating plasmid DNA containing the pIX gene was introduced into HeLa cells by the DEAE-dextran method, no pIX gene transcript was detected. In contrast, efficient transcription was observed in the cells transfected with a replicating plasmid containing the pIX gene. Adenovirus early genes did not affect the level of transcription of the pIX gene on either a nonreplicating or a replicating plasmid. Inhibition of plasmid replication with cytosine arabinoside prevented transcription of the pIX gene. By quantitative analysis of the amount of the pIX gene and its transcript in transfected cells, it was concluded that active transcription of the pIX gene occurred only on DNA molecules replicated in the cell.

scholarly journals Effect of Chromatographic Conditions on Supercoiled Plasmid DNA Stability and Bioactivity

2019 ◽  
Vol 9 (23) ◽  
pp. 5170 ◽  
Author(s):  
G.M. Azevedo ◽  
J.F.A. Valente ◽  
A. Sousa ◽  
A.Q. Pedro ◽  
P. Pereira ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Plasmid Dna ◽  
P53 Protein ◽  
Metabolic Stress ◽  
Suppressor Gene ◽  
Experimental Conditions ◽  
P53 Expression ◽  
Supercoiled Plasmid ◽  
Protein P53

The dysfunction of the tumor suppressor gene TP53 has been associated with the pathogenesis of the majority of the cases of cancer reported to date, leading the cell to acquire different features known as the cancer hallmarks. In normal situations, the protein p53 protects the cells against tumorigenesis. By detecting metabolic stress or DNA damage in response to stress, p53 can lead the cell to senescence, autophagy, cell cycle arrest, DNA repair, and apoptosis. Thus, in the case of p53 mutations, it is reasonable to assume that the reestablishment of its function, may restrain the proliferation of cancer cells. The concept of cancer gene therapy can be based on this assumption, and suitable biotechnological approaches must be explored to assure the preparation of gene-based biopharmaceuticals. Although numerous procedures have already been established to purify supercoiled plasmid DNA (sc pDNA), the therapeutic application is highly dependent on the biopharmaceutical’s activity, which can be affected by the chromatographic conditions used. Thus, the present work aims at comparing quality and in vitro activity of the supercoiled (sc) isoform of the p53 encoding plasmid purified by three different amino acids-based chromatographic strategies, involving histidine–agarose, arginine–macroporous, and histidine–monolith supports. The B-DNA topology was maintained in all purified pDNA samples, but their bioactivity, related to the induction of protein p53 expression and apoptosis in cancer cells, was higher with arginine–macroporous support, followed by histidine–monolith and histidine–agarose. Despite the purity degree of 92% and recovery yield of 43% obtained with arginine–macroporous, the sc pDNA sample led to a higher expression level of the therapeutic p53 protein (58%) and, consequently, induced a slightly higher apoptotic effect (27%) compared with sc pDNA samples obtained with histidine–monolithic support (26%) and histidine–agarose support (24%). This behavior can be related to the mild chromatographic conditions used with arginine–macroporous support, which includes the use of low salt concentrations, at neutral pH and lower temperatures, when compared to the high ionic strength of ammonium sulfate and acidic pH used with histidine-based supports. These results can contribute to field of biopharmaceutical preparation, emphasizing the need to control several experimental conditions while adapting and selecting the methodologies that enable the use of milder conditions as this can have a significant impact on pDNA stability and biological activity.

A quantitative analysis of the supercontraction-induced molecular disorientation of major ampullate spider silk

2017 ◽  
Vol 19 (46) ◽  
pp. 31487-31498 ◽  
Author(s):  
J. Dionne ◽  
T. Lefèvre ◽  
P. Bilodeau ◽  
M. Lamarre ◽  
M. Auger
Keyword(s):  
Quantitative Analysis ◽  
Spider Silk ◽  
Structural Changes

Quantitative analysis of the molecular disorientation and structural changes of major ampullate spider silk upon water-induced supercontraction.

Degradation of supercoiled plasmid DNA within a capillary device

2007 ◽  
Vol 97 (5) ◽  
pp. 1148-1157 ◽  
Author(s):  
F.J. Meacle ◽  
H. Zhang ◽  
I. Papantoniou ◽  
J.M. Ward ◽  
N.J. Titchener-Hooker ◽  
...  
Keyword(s):  
Plasmid Dna ◽  
Supercoiled Plasmid
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