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Updated: Jun 4, 2026

In vitro Assembly of Semi-artificial Molecular Machine and its Use for Detection of DNA Damage
Published on: January 11, 2012
Melting of DNA-actinomycin clusters
1Institute of Cell Biophysics of Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia. nvekshin@rambler.ru
Abstract:
Differential methods of scanning micro-calorimetry and UV spectrophotometry were used for understanding the interaction of natural anti-tumour antibiotic actinomycin D with cluster sites of native and fragmented DNA during thermal melting. At low (micro-molar) concentrations, the actinomycin molecules penetrate into unwound regions of DNA, but not into the double helix. Moreover, they stabilize the fragmented DNA and increase a total melting point. Actinomycin D interacts with fractions of native DNA even at very low concentrations (at the antibiotic/nucleotide ratio of 1:868) and stabilizes the most loose clusters. At high concentrations, it destabilizes the double helix.
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