• Ternary complexes of cobalt cysteinylglycine with histidylserine and histidylphenylalanine-stabilities and DNA cleavage properties

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      https://www.ias.ac.in/article/fulltext/jcsc/119/06/0603-0612

    • Keywords

       

      Cobalt(II); dipeptides; 1H and C13 NMR; DNA binding; DNA hydrolytic cleavage; kinetics.

    • Abstract

       

      Interaction of cobalt cysteinylglycine with histidylserine and histidylphenylalanine was investigated in a 1 : 1 : 1 ratio at 35°C and 0.10 mol dm-3 ionic strength. Their stabilities and geometries were determined. Their DNA binding and cleavage properties were investigated. The intrinsic binding constants ($K_b$) for DNA bound 1 and 2 ($3.03 \times 10^3$ M-1 for 1 and $3.87 \times 10^3$ M-1 for 2) were determined. Even though the negative charge on the complexes reduced their affinity for DNA, there was an enhancement of binding through specificity. The degradation of plasmid DNA was achieved by cobalt dipeptide complexes [CoII(CysGly)(HisSer)] (1) and [CoII(CysGly)(HisPhe)] (2). Cleavage experiments revealed that 1 and 2 cleave supercoiled DNA (form I) to nicked circular (form II) through hydrolytic pathway at physiological 𝑝H. The DNA hydrolytic cleavage rate constants for complexes 1 and 2 were determined to be 0.62 h-1, for 1 and 0.38 h-1 for 2 respectively.

    • Author Affiliations

       

      Pulimamidi R Reddy1 Pallerla Manjula1

      1. Department of Chemistry, Osmania University, Hyderabad 500 007
    • Dates

       
  • Journal of Chemical Sciences | News

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