Studies of a specific association between acriflavine and DNA in intact cells

Abstract

SynopsisThe nature of a specific association between acriflavine and cellular DNA was investigated by subjecting the DNA of intact cells to denaturation, ultraviolet radiation, and base analog substitution. The predictable modifications of DNA structure were then correlated with the quantitative alterations in dye adsorption by the cells. It was concluded that, under experimental conditions of limited dye availability, the bonding of dye was restricted to sites of highest bonding affinity. These were shown to be situated between adjacent thymine molecules on a single strand of DNA. The bmethyl groups of thymine may endow the bond with its specificity.The high bonding affinity between diaminoacridines and nucleic acids is demonstrable intracellularly as well as in purified reaction systems. 1-- 8 We have conducted studies of the bonding of acriflavine and the DNA of intact cells in the hope that, by keeping the ordered structure of the nucleoprotein-cation complex as intact as possible, additional information about this affinity might be gained. By the term "specific association" we refer to the selective and near-stoichiometric adsorption of acriflavine to cellular DNA as previously ascertained and r e p~r t e d .~. '~ The conditions for this were met by limiting amounts of dye in a standardized experimental model which restricts the association of dye and cellular anions to sites of highest bonding affinity.We are now reporting some changes in this bond produced by modifying cellular DNA with heat, ultraviolet radiation, and base analog substitution. We interpret the data as support for the concepts recently advanced by several a~t h o r s '~-'~ which, in their aggregate, point away from the complete intercalation model proposed by Lermanl8 and toward one in which diaminoacridines associate preferentially with adjacent thymine-containin.g base pairs in a strong bond which is disposed toward one of the DNA strands. Our data further suggest that the preferred binding site is situated between two adjacent thymine molecules whose 5-methyl groups endow the interaction with its specificity. 695

Local acriflavine: A new therapy for rhinoscleroma

“…In addition to its use as a dye, it has an active antibacterial action against most gram-positive and negative organisms, and it is a valuable drug in Giardiasis (Albert, 1951);Culbertson, 1941). Acriflavine is also used as a mutigenic agent, and this effect has been applied for the production of several mutants of many organisms (Freese, 1959;Brenner,efa/., 1961;Roth and Manjon, 1969). Acriflavine has also been reported to produce-in vitro-a lethal action on K. Rhinoscleromatis bacilli cultured on nutrient agar plates (Rizk, 1977).…”

Protection of Normal, Lysogenic, and Pyocinogenic Strains Against Ultraviolet Radiation by Bound Acriflavine

“…Effect of acriflavine remaining bound after the washing of acriflavine-treated suspensions. It has been observed that acridines bind firmly to nucleic acid (12,16,22), and acriflavine remained protective, though to a reduced extent, when bacterial suspensions were washed after acriflavine treatment (Fig. 8).…”

“…Although agreement is lacking on the precise mode of binding of acridine molecules to nucleic acid (12,16), it is well established that the presence of these dyes reduces the yield of thymine dimers in ultraviolet (UV)-irradiated deoxyribonucleic acid (DNA) (6,20,21). Setlow and Carrier (20) presented dose-effect curves for the inhibition of thymine-thymine and cytosine-thymine dimers in Escherichia coli DNA by proflavine at 1.5 x 10-5 M. Their data suggest that the reduction factor was constant for doses of UV at 280 nm up to about 104 ergs/mm2, in which range dimer formation proceeds linearly with dose, and preliminary measurements of our own for irradiation at 254 nm, with acriflavine as protective agent, likewise demonstrate a factor for reduction which is constant up to doses much larger than any we used in the biological experiments to be reported.…”