title: [Molecular mechanisms of the damaging effect of laser radiation on DNA].
abstract: The effects of DNA photoscission were studied in the presence of ethidium bromide (EB) and riboflavin (RF) (vitamin B2). Laser irradiation (337 nm) of DNA in the presence of EB and RF induces single- and double-strand scissions in the superhelical form of DNA pBR322 (registered as increasing content of its nicked and linear forms). Possibility of DNA scission by energy absorbed by a nonintercalating chromophore (riboflavin) was demonstrated for the first time. The dependence of DNA photoscission in complex with riboflavin on the energy density in the pulse suggests a nonlinear (two-quantum) character of the photoscission process. It was shown that for riboflavin the quantum yield of DNA photoscission exceeds several times the one for ethidium bromide.
authors.forename: A I
authors.initials: AI
authors.lastname: Dragan
authors.forename: S N
authors.initials: SN
authors.lastname: Khrapunov
mesh_terms: D004249:DNA Damage; D004274:DNA, Recombinant / Q000737:chemistry / Q000528:radiation effects*; D004996:Ethidium / Q000737:chemistry; D007834:Lasers; D010957:Plasmids; D012256:Riboflavin / Q000737:chemistry
chemical_list: D004274:DNA, Recombinant; D004996:Ethidium; D012256:Riboflavin
vernacular_title: Molekuliarnye mekhanizmy povrezhdaiushchego deĭstviia lazernogo izlucheniia na DNK.