Binding of platinum(II) intercalation reagents to deoxyribnonucleic acid. Dependence on base-pair composition, nature of the intercalator, and ionic strength
Autor: | Mary Howe-Grant, Stephen J. Lippard |
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Rok vydání: | 1979 |
Předmět: |
DNA
Bacterial Base (chemistry) Chemical Phenomena Base pair Clostridium perfringens Inorganic chemistry Intercalation (chemistry) chemistry.chemical_element Salt (chemistry) Thymus Gland Biochemistry Micrococcus Structure-Activity Relationship Escherichia coli Animals Platinum chemistry.chemical_classification Base Composition Chemistry Osmolar Concentration DNA Solvent Crystallography Kinetics Ionic strength Reagent Cattle |
Zdroj: | Biochemistry. 18(26) |
ISSN: | 0006-2960 |
Popis: | The DNA binding of three platinum(II) intercalation reagents has been studied and found to depend upon base composition, the nature of the intercalator, and the ionic strength of the solvent medium. In 0.2 M NaCl, binding data for calf thymus DNA show the association constants to be approximately 10(4) M-1. The binding constants decrease in the order [(o-phen)Pt(en)]2+ greater than or equal to [(terpy)Pt(HET)]+ greater than [(bipy)Pt(en)]2+. The number of available intercalation sites for the doubly charged intercalators is only 70% of the number expected from the nearest-neighbor exclusion model. Binding of [(o-phen)Pt(en)]2+ and [(terpy)Pt(HET)]+ to various DNAs depends linearly on G.C content. Both reagents exhibit essentially the same degree of G.C specificity. Intercalative binding is a function of ionic strength. Increasing the salt concentration minimizes the importance of metallointercalator charge, and extrapolation to 1 M salt reveals the intercalative abilities, as reflected in binding constants, to be equivalent for [(terpy)Pt(HET)]+ and [o-phen)Pt(en)]2+ and about 1 order of magnitude less than that of ethidium. |
Databáze: | OpenAIRE |
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