Cooperativity or phase transition? Unfolding transition of DNA cationic surfactant complex

Autor:	Kenichi Yoshikawa, Sergey M. Mel'nikov, Hiroshi Takahashi, Vladimir G. Sergeyev, Ichiro Hatta
Rok vydání:	1997
Předmět:	Phase transition Chemistry digestive oral and skin physiology Cationic polymerization General Physics and Astronomy Cooperativity chemistry.chemical_compound Crystallography Sodium bromide Pulmonary surfactant Bromide Molecule Physical and Theoretical Chemistry DNA
Zdroj:	Scopus-Elsevier
ISSN:	1089-7690 0021-9606
DOI:	10.1063/1.474932
Popis:	We recently reported that single duplex DNA, with the size above the order of several tens kilobase pairs, undergoes a large discrete transition from an elongated coil into a collapsed globule with the addition of a cationic surfactant. In the present article, we describe the manner of the unfolding transition of compact long DNA, or globule DNA, complexed with cationic surfactants, cetyltrimethylammonium bromide (CTAB) and distearyldimethylammonium bromide (D18DAB), as is induced by the addition of sodium bromide. The conformational dynamics of individual single duplex T4DNA molecules was directly observed with the use of fluorescence microscopy. We found that on the level of individual DNAs, the salt-induced unfolding transition of the globules is largely discrete, or first-order phase transition for the both complexes with CTAB and D18DAB. On the other hand, for the ensemble average of the DNAs, the transition is discrete with CTAB but is continuous (sigmoidal) with D18DAB. The discreteness for the coi...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::988b35801efc8e74c797f12d640f78de https://doi.org/10.1063/1.474932 Zobrazit plný text záznamu