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Updated: Aug 18, 2026

Combining Single-molecule Manipulation and Imaging for the Study of Protein-DNA Interactions
Published on: August 27, 2014
Studies on the interaction between steffimycins and DNA
Abstract:
The complexes formed between steffimycins and DNA were studied using various physicochemical techniques. The binding process has been followed spectrophotometrically or fluorimetrically. The binding parameters n and K, evaluated according to McGhee and Von Hippel, show a good affinity of these antibiotics for the macromolecule. Flow dichroism measurements showed that in the complex with DNA, the antracycline moiety of the steffimycins is intercalated between two base pairs of the macromolecule. The binding experiments with various polydeoxyribonucleotides and with various DNA samples, having different base pair compositions, suggest that an alternate sequence of A-T, such as that of poly[d(A-T)] . poly[d(A-T)], represents a good receptor site for the binding of steffimycins to DNA. The lack of in vivo activity of these antibiotics is discussed.
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