Calorimetric studies of the interaction between DNA and poly-L-lysine.
The transition enthalpy deltaH of the helix-random coil transition of the DNA-polylysine complex was measured as a function of the peptide:nucleotide ratio by the help of an adiabatic scanning differential calorimeter. Furthermore the transition enthalpy of a complex with a specific peptide:nucleotide ratio was determined as a function of the cation concentration of the solution. Finally the reaction enthalpy of the interaction of polylysine with native and denatured DNA was measured with the help of a LKB batch calorimeter. From the results of the calorimetric measurements one can conclude that the transition enthalpy of the DNA-polylysine complexes is linearly dependent on the nucleotide: peptide ratio. The extrapolated value for the 1:1 complex is 14.4 kcal per mole base pairs.
D000818:Animals; D002151:Calorimetry; D002417:Cattle; D004247:DNA; D046911:Macromolecular Substances; D009690:Nucleic Acid Conformation; D010455:Peptides; D011107:Polylysine; D011485:Protein Binding; D011487:Protein Conformation; D013696:Temperature; D013816:Thermodynamics; D013950:Thymus Gland
D046911:Macromolecular Substances; D010455:Peptides; D011107:Polylysine; D004247:DNA