Nonaqueous solutions of DNA. Denaturation in methanol and ethanol

Interaction of nucleic acids with carbon nanotubes and dendrimers

“…The transition from the stable B-DNA form to other forms such as A-DNA or Z-DNA can be triggered by protein binding or by changing the solvent conditions (Herskovits and Singer 1961;Ivanov et al 1974;Zimmerman and Pheiffer 1979;Calladine and Drew 1984;Jovin et al 1987;Dickerson 1992 ethanol-water mixture solution. In the presence of water, the formation of hydration shells around Na + counterions partially inhibits the strong counterion condensation around the negatively charged phosphate atoms that increases electrostatic repulsion between phosphate atoms.…”

PM6 quantum chemical study of the H-bonded and stacked associates of the adenine and thymine DNA bases: The nature of base stacking

“…∆E form = ∆E bb (gas) + ∆E dc (wat) + ∆E wb + ∆E ww (6) Here, the distortion cost, ∆E dc (wat), defined as the internal energy difference between the paired and isolated bases caused by the presence of the water cluster and by geometric changes during the base association reaction, is given by:…”

“…In contrast, thermodynamic and spectroscopic studies on nucleic acid bases, nucleosides and nucleotides in aqueous solution have shown the formation of exclusively stacked associates [5]. The underlying physical forces that lead to base stacking are, however, not well understood and, indeed, the phenomenon has been attributed alternatively to the hydrophobic effect [6], dispersion interactions [7] and electrostatic interactions [8].…”

An Introduction to Transcription and Gene Regulation

“…Finding that DNA denatures and collapses when water is substituted by ethanol (6) led to a wider exploration of DNA denaturation by other non-aqueous solvents. Ted Herskovits took up this subject for his Ph.D. thesis (at Yale) (7).…”

“…My prior experience with the apparent transcriptional fidelity of crude bacterial extracts (47) led me to expect that the functions of the gene 55 and gene 33 products might be manifested in a straightforward way in in vitro transcription experiments. 7 Accordingly, essentially repeating Khesin's prior work, I prepared a crude extract from wild-type phage T4-infected cells, used that material to transcribe T4 DNA, and analyzed the labeled RNA product by hybridization-competition against RNA extracted from wildtype phage-infected bacteria at early and late times of the multiplication cycle. My results merely confirmed what Khesin's group already had seen: I also failed to detect the synthesis of late RNA in anything like the proportions in which it was being produced in the phage-infected cells from which the extracts were made.…”