Interaction of spermine and DNA

✍ Scribed by Shalom Z. Hirschman; Marc Leng; Gary Felsenfeld

• Publisher: Wiley (John Wiley & Sons)
• Year: 1967
• Tongue: English
• Weight: 360 KB
• Volume: 5
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1967.360050209

✦ Synopsis

The effect of spermine upon the denaturation temperatuie (Tm) of DNA's of various base compositions has been found to depend upon both the base composition of the DNA and the pH of the solution. Measurement of the hydrogen ion titration curve of spermine as a function of temperature reveals that the net charge of the spermine molecule is undergoing a rapid change with temperature in the range of temperatuies a t which DNA denatures. Since the value of Tm depends upon base composition, the correlation of the effect of spermine upon Tm with the base composition of the DNA used may be explainable in terms of the changing degree of ionization of spermine. The binding of spermine to native DNA has also been studied by dialysis equilibrium. There is no significant vaiiation either in the number of strongly binding sites or strength of binding with base composition. It is concluded that there is no evidence of correlation between the binding of spermine and the base composition of DNA.