scholarly journals Cationic Single-Chained Surfactants with a Functional Group at the End of the Hydrophobic Tail DNA Compacting Efficiency

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 589
Author(s):  
José Antonio Lebrón ◽  
Pilar López-Cornejo ◽  
Elena García-Dionisio ◽  
Pablo Huertas ◽  
Margarita García-Calderón ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Functional Group ◽  
Transfection Efficiency ◽  
Constitutive Expression ◽  
Regulatory Elements ◽  
Ammonium Bromide ◽  
Calf Thymus ◽  
Key Factor ◽  
Hydrophobic Tail ◽  
Self Aggregation

The interaction between calf-thymus DNA, ctDNA, and various single-chained surfactants with different functional groups at the end of hydrophobic tail was studied with the goal of investigating the influence of the functional group nature on surfactant DNA compacting efficiency. The surfactants investigated were dodecyltriethylammonium bromide (DTEABr), triethyl(1-phenoxydodecyl)ammonium bromide (12PhBr), triethyl(2-naphthoxydodecyl)ammonium bromide (12NBr) and 11-(isonicotinoyloxy)-N,N,N-triethyl-1-undecanaminium bromide (11PyBr). Results made evident that the surfactants’ tendencies to self-aggregation is the key factor determining their efficiency to compact the nucleic acid. Subsequently, DOPE/12NBr/pEGFP-C1 lipoplexes, with different cationic surfactant molar fractions (α) and mass ratios (L/D), were prepared and characterized. DOPE is a zwitterionic phospholipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine, and the plasmid pEGFP-C1 carries a GFP coding sequence with the necessary regulatory elements for constitutive expression of the gene in human cells. 12NBr was chosen because it was the most efficient DNA compacting agent among the surfactants investigated. Finally, the cytotoxicity and transfection efficiency (TE) of DOPE/12NBr/pDNA lipoplexes, with different compositions, were investigated.

scholarly journals Evolution of a cis-acting SNP that controls Type VI Secretion in Vibrio cholerae

2022 ◽  
Author(s):  
Siu Lung Ng ◽  
Sophia A. Kammann ◽  
Gabi Steinbach ◽  
Tobias Hoffmann ◽  
Peter J. Yunker ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Phenotypic Diversity ◽  
Constitutive Expression ◽  
Regulatory Elements ◽  
Regulatory Control ◽  
Type Vi Secretion System ◽  
Type Vi Secretion ◽  
Intergenic Regions

Mutations in regulatory mechanisms that control gene expression contribute to phenotypic diversity and thus facilitate the adaptation of microbes to new niches. Regulatory architecture is often inferred from transcription factor identification and genome analysis using purely computational approaches. However, there are few examples of phenotypic divergence that arise from the rewiring of bacterial regulatory circuity by mutations in intergenic regions, because locating regulatory elements within regions of DNA that do not code for protein requires genomic and experimental data. We identify a single cis-acting single nucleotide polymorphism (SNP) dramatically alters control of the type VI secretion system (T6), a common weapon for inter-bacterial competition. Tight T6 regulatory control is necessary for adaptation of the waterborne pathogen Vibrio cholerae to in vivo conditions within the human gut, which we show can be altered by this single non-coding SNP that results in constitutive expression in vitro. Our results support a model of pathogen evolution through cis-regulatory mutation and preexisting, active transcription factors, thus conferring different fitness advantages to tightly regulated strains inside a human host and unfettered strains adapted to environmental niches.

scholarly journals Abundant constitutive expression of the immediate-early 94K protein from cytomegalovirus (Colburn) in a DNA-transfected mouse cell line.

1984 ◽  
Vol 4 (10) ◽  
pp. 2214-2223 ◽  
Author(s):  
K T Jeang ◽  
M S Cho ◽  
G S Hayward
Keyword(s):  
Cell Line ◽  
Mammalian Cells ◽  
Regulatory Region ◽  
Constitutive Expression ◽  
Regulatory Elements ◽  
Mouse Cell ◽  
Cellular Protein ◽  
Immediate Early ◽  
Early Protein ◽  
Infected Cells

A 94-kilodalton phosphoprotein known as IE94 is the only viral polypeptide synthesized in abundance under immediate-early conditions after infection by cytomegalovirus (CMV) strain Colburn in either permissive primate or nonpermissive rodent cells. The IE94 gene, which maps at coordinates 0.71 to 0.73 in the viral genome, contains a large intron in the 5' leader sequence, and its promoter regulatory region contains novel, multiple-palindromic, repeated elements. Two recombinant plasmids (pTJ148 and pTJ198) containing the 10.5-kilobase-pair HindIII-H DNA fragment from CMV (Colburn) were transfected into mouse Ltk- cells, by either linked or unlinked coselection in hypoxanthine-aminopterin-thymidine medium, together with herpes simplex virus thymidine kinase genes. With both procedures, constitutive synthesis of the IE94 immediate-early protein was detected in pools of Ltk+ cells by immunoprecipitation. Subsequently, we isolated a clonal Ltk+ cell line which expressed the [35S]methionine-labeled IE94 polypeptide in sufficient abundance to be visualized directly in autoradiographs after gel electrophoresis of total-cell-culture protein extracts. The IE94 polypeptide synthesized in the transfected cells was indistinguishable in size and overall net charge from that produced in virus-infected cells. In addition, the IE94 protein expressed in LH2p198-3 cells was phosphorylated (presumably by a cellular protein kinase) and generated similar phosphopeptide patterns after partial tryptic digestion to those obtained with the CMV IE94 protein from infected cells. The cell line contained two to four stably integrated copies of the IE94 gene and synthesized a single virus-specific mRNA of 2.5 kilobases detectable on Northern blots. A new antigen, detectable by indirect anticomplement immunofluorescence with monoclonal antibody against the human CMV IE68 protein, was present in the nuclei of more than 95% of the LH2p198-3 cells. This evidence suggests that (unlike most herpesvirus genes) the CMV IE94 gene, together with its complex promoter and spliced mRNA structure, may contain all of the regulatory elements necessary for strong constitutive expression in mammalian cells in the absence of other viral factors.

PROPERTIES OF CALF THYMUS HISTONE ISOLATED BY THREE DIFFERENT METHODS

1958 ◽  
Vol 36 (1) ◽  
pp. 1-13 ◽  
Author(s):  
L. B. Smillie ◽  
G. C. Butler ◽  
David B. Smith
Keyword(s):  
Nucleic Acid ◽  
Hydrochloric Acid ◽  
Aqueous Solutions ◽  
Sedimentation Rate ◽  
Principal Components ◽  
Dilute Hydrochloric Acid ◽  
Original Material ◽  
Salting Out ◽  
Calf Thymus ◽  
Two Stages

Histone of calf thymus deoxyribonucleoprotein was isolated by three different methods: (1) Extraction from nucleoprotein solutions with dilute hydrochloric acid. (2) Extraction from cold saline nucleoprotein solutions with ethanol. (3) Salting out part of the histone, followed by removal of the nucleic acid from the remainder as an insoluble lanthanum salt. Similar yields were obtained in all cases. Measurements of fractional solubility, electrophoretic mobility, and sedimentation rate disclosed the presence of two principal components corresponding roughly to those obtained in the two stages of method (3). Alterations of one component were found to take place in aqueous solutions more alkaline than pH 4.0, resulting in the appearance of artifacts some of which sedimented more rapidly, while others sedimented more slowly, than the original material.

THE SEPARATION OF CALF THYMUS NUCLEIC ACID AND HISTONE BY ALCOHOL–SALT PRECIPITATION

1955 ◽  
Vol 33 (1) ◽  
pp. 263-271 ◽  
Author(s):  
L. B. Smillie ◽  
A. M. Marko ◽  
G. C. Butler
Keyword(s):  
Sodium Chloride ◽  
Nucleic Acid ◽  
Aqueous Solutions ◽  
Distilled Water ◽  
Salt Precipitation ◽  
Salt Solutions ◽  
Desoxyribonucleic Acid ◽  
Concentrated Aqueous Solutions ◽  
Calf Thymus ◽  
Quantitative Separation

Extraction of the histone of thymonucleoprotein with alcohol and salt has been studied with varying concentrations of alcohol, sodium chloride, and nucleoprotein and with varying pH and temperature. The addition of 0.5–1.0 volumes of ethanol to a solution of nucleoprotein (approximately 1 mgm. N/ml.) in 3 M sodium chloride has been found to effect an almost quantitative separation of desoxyribonucleic acid and protein. It has proved feasible to prepare concentrated aqueous solutions of the extracted protein by successive dialysis against strong salt solutions at −10 °C. and against distilled water at 5 °C. followed by pervaporation at 5 °C. The properties of the isolated nucleate have indicated a highly polymerized product.

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