title: Dimerization kinetics of violamycin BI anthracycline--the influence of ionic strength.
abstract: Violamycin BI is an anthracycline derivative with two sugars hanging on, each of them carries one positive charge. It dimerizes under conditions, which depend on the concentration of the antibiotic, pH and the ionic strength of the solution. By keeping a constant pH in a phosphate-EDTA buffer, the rate constants of violamycin BI dimerization were determined at various ionic strengths by temperature jump method. The dimerization constant Kd, resulting from the ratio of these rate constants, confirmed the values obtained spectrophotometrically in this study or elsewhere. The influence of ionic strength (0.02-0.2 M) on the rate constant values suggested to us some speculations on the reaction mechanism of the dimerization, in which, the specific mutual orientation of the monomers in the encounter, and perhaps a specific conformation of their side groups is required before a stabilizing action of the binding forces sets in.
authors.forename: T
authors.initials: T
authors.lastname: Oncescu
authors.forename: S
authors.initials: S
authors.lastname: Memedula
authors.forename: L C
authors.initials: LC
authors.lastname: De Maeyer
mesh_terms: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D019281:Dimerization; D004492:Edetic Acid; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008956:Models, Chemical; D009994:Osmolar Concentration
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; C022171:violamycin BI; D004492:Edetic Acid