INTERACTION OF SULFUR-CONTAINING RADIOPROTECTORS WITH DNA - A SPECTROPHOTOMETRIC STUDY

  • 1 January 1980
    • journal article
    • research article
    • Vol. 12  (1) , 51-55
Abstract
The interaction between Na-compensated DNA [from Escherichia coli] and several aminothiol radioprotectors [cysteamine; methyl-2-cysteamine; cysteamine phosphorothioate; N-(2-mercaptoethyl)1,2-diaminoethane; N-(2-mercaptoethyl)-1,3-diaminopropane; N-(3-aminopropyl)-2-aminoethyl phosphorothioic acid] were studied by spectrophotometry. Elevation of the melting point (Tm) of the DNA-radioprotector complex was observed in all cases. The interaction of these ionized aminothiols with phosphate groups of DNA is essentially electrostatic, similar to that for metallic cations, and is expressed by the Schildkraut-Lifson equation Tm = a log Cradio + b, where a and b are adjustable parameters and Cradio is the concentration of the radioprotectors.