title: Alpha-particle-induced changes in the stability and size of DNA.
abstract: The effect of alpha-particle radiation on the thermal stability and size of calf thymus DNA molecules in deoxygenated aqueous solutions was investigated by thermal transition spectrophotometry, pulsed-field gel electrophoresis, and standard agarose gel electrophoresis. The thermal transition of DNA from helix to coil was studied through analysis of the UV A(260) absorbance. The results obtained for alpha particles of mean LET of 128 keV microm(-1) reveal a dual dose response: a tendency for thermal stability of the DNA helix at "low" doses, followed by an increasing instability at higher doses. The same phenomenon was observed for the mean molecular weight of DNA molecules exposed to alpha particles. The results reported here for alpha particles in the low-dose region of 0-16 Gy are consistent with our previous hypothesis of inter- and intramolecular interactions of a covalent character in gamma-irradiated DNA molecules in the dose region of 0-4 Gy.
authors.affiliation: Institute of Biology, National Center for Scientific Research "DEMOKRITOS", Agia Paraskevi, 153 10 Athens, Greece.
authors.forename: A G
authors.initials: AG
authors.lastname: Georgakilas
authors.forename: K S
authors.initials: KS
authors.lastname: Haveles
authors.forename: V
authors.initials: V
authors.lastname: Sophianopoulou
authors.forename: L
authors.initials: L
authors.lastname: Sakelliou
authors.forename: G
authors.initials: G
authors.lastname: Zarris
authors.forename: E G
authors.initials: EG
authors.lastname: Sideris
mesh_terms: D000512:Alpha Particles; D000818:Animals; D002417:Cattle; D004247:DNA / Q000737:chemistry / Q000528:radiation effects*; D053938:DNA Fragmentation; D009691:Nucleic Acid Denaturation; D009695:Nucleic Acid Renaturation
chemical_list: D004247:DNA