title: Compaction and multiple chain assembly of DNA with the cationic polymer poly(aluminum chloride) (PAC).
abstract: Assembly of DNA molecules by the addition of poly(aluminum chloride) (PAC) was studied. In the absence of PAC, electron microscopy indicated the formation of elongated coiled DNA molecules. In the presence of PAC, multiple doughnut-like structures, 8-15 nm thick, formed and fused together. When salt was added, the doughnut-like structures tended to be thinner and the morphology of the fused doughnuts became irregular. We obtained a view of a single DNA structure by fluorescent microscopy, which revealed that individual DNA molecules undergo a discrete transition from an elongated to compacted state with an increase in PAC concentration. Electron microscopic observation showed that a regular doughnut is the typical structure seen under low salt conditions. At high salt concentrations, the doughnut shape deformed, yielding results similar to those produced by the salt effect on DNA assembly at high DNA concentrations.
authors.affiliation: Department of Ecological Engineering, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Matsuzawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Kanbe
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yoshikawa
mesh_terms: D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D008968:Molecular Conformation; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013499:Surface Properties
chemical_list: D017607:Aluminum Compounds; D002412:Cations; D002712:Chlorides; D011108:Polymers; D000077410:Aluminum Chloride; D012965:Sodium Chloride; D004247:DNA