The influence of $\mathrm{pH}$ on interaction of $\mathrm{CuTOEPyP4}$ with $\mathrm{DNA}$

The interaction of $\mathrm{Cu(II)}$-meso-tetra-($\mathrm{4N}$-hydroxyethylpyridyl)porphyrim ($\mathrm{CuTOEPyP4}$) with $\mathrm{DNA}$ at different $\mathrm{pH}$ was studied by methods of spectrophotometry and circular dichroism. It was shown that these porphyrins bind to $\mathrm{DNA}$ preferably via intercalation. The calculations show that the constant of binding of $\mathrm{CuTOEPyP4}$ with $\mathrm{DNA}$ strongly depend upon the $\mathrm{pH}$.