pH-dependent complex formation of Zn-meso-tetra(4-N-hydroxyethylpyridyl) porphyrin with cancer DNA

Abstract

The complex formation between the synthetic water-soluble Zn-meso-tetra(4-N-hydroxyethylpyridyl) porphyrin (ZnTOEPyP4) and cancer DNA in comparison to healthy DNA was investigated using the UV/VIS spectrophotometry method in phosphate-buffered saline at different pHs. The increasing of DNA/porphyrin ratio leads to hypochromicity and red shift in the Soret band, which indicate the complexation of the ZnTOEPyP4 with DNA. The results show that the binding constant ($K_b$) and the exclusion parameter ($n$) of ZnTOEPyP4 with DNA strongly depend upon the pH. The $K_b$of ZnTOEPyP4 with cancer DNA is higher than with normal DNA.

Communicated by Ramaswamy H. Sarma

Keywords:

• cancer DNA
• porphyrin
• spectrophotometry
• binding parameters

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Committee of Science Republic of Armenia (grant no. 18T-1F055).