The Effect of an Amino‐Acid Bridge on Binding Affinity and Cleavage Efficiency of Pyrenyl‐Macrocyclic Polyamine Conjugates toward DNA

Abstract

A series of pyrenyl-macrocyclic polyamines 5a-5c have been prepared and characterized. Their DNA-cleavage properties were examined under physiological conditions. Without the presence of other additives, the DNA cleavage ability of 5a-5c showed the order of 5c>5a>5b. Absorption and fluorescence experiments showed the binding affinity of 5a-5c to DNA. The interactions of 5a-5c with CT-DNA indicated that the DNA binding ability followed an order according to their cleavage efficiency. All the results indicated that the structures of amino-acid bridge in the ligands may affect the DNA binding and cleavage ability. The cleavage-mechanism studies indicated that singlet oxygen and superoxide free radicals were involved in the catalytic DNA cleavage process.

Polyamine–Oligonucleotide Conjugates: 2′-OMe-Triazole-Linked 1,4,7,10-Tetraazacyclododecane and Intercalating Dyes and Their Effect on the Thermal Stability of DNA Duplexes

“…Steward et al demonstrated a four-arm, lattice-bearing, single-stranded DNA bound to the central Ni(II)-cyclen complex, which improves self-assembly at the supramolecular level, but its effect on duplexes is also unknown [4]. On the other hand, it is known that macrocyclic polyamines such as 1,4,7,10tetraazacyclododecane (cyclen) are potential artificial nucleases, and their derivatives can cleave double-stranded DNA (dsDNA), even without metal ions, through hydrolysis or oxidative cleavage [5][6][7][8][9]. Thus, covalent attachment of a macrocyclic amine to ssDNA may provide new and useful models for studying the function and in vitro use of artificial nucleic acid-based nucleases.…”