title: Interaction of anthracycline antibiotics with biopolymers: comparative studies of DNA binding and antimicrobial activity of rhodomycin-type anthracycline antibiotics.
abstract: The binding of the anthracyclines beta-rhodomycin-I and beta-rhodomycin-II to calf thymus DNA was investigated by both equilibrium and kinetic methods taking into account ligand dimerization (ionic strength I = 0.2 M, pH 6.0). The analysis was based upon a cooperative single-step binding mechanism with overlapping of potential binding sites on a linear homogeneous lattice. Equilibrium binding parameters were estimated from spectrophotometric titration experiments by means of a nonlinear fitting program. The results were compared with those obtained previously for the related antibiotic iremycin and were complemented by kinetic parameters determined from temperature-jump experiments at high binding ratio. The binding constants and the mean attachment times of the drugs were found to increase in the serial order iremycin, beta-rhodomycin-I and beta-rhodomycin-II, which is in line with their increasing antimicrobial activity on Bacillus subtilis ATCC 6633.
mesh_terms: D018943:Anthracyclines; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D000903:Antibiotics, Antineoplastic; D001412:Bacillus subtilis / Q000187:drug effects*; D004247:DNA / Q000378:metabolism*; D007700:Kinetics; D009279:Naphthacenes / Q000378:metabolism / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D018943:Anthracyclines; D000900:Anti-Bacterial Agents; D000903:Antibiotics, Antineoplastic; D009279:Naphthacenes; C004977:rhodomycin; D004247:DNA