Structure–function study of peroxidase-like G-quadruplex-hemin complexes

Abstract

The structure–function relationship of G-quadruplex-hemin complexes with peroxidase activity was studied by comparing peroxidase activity and circular dichroism (CD) spectra of 22 oligonucleotides with the sequence of d(G₂T_n)₃G₂, d(G₃T_n)₃G₃ (n = 1–4) and dG₃T_iG₃T_jG₃T_kG₃. According to the experimental results, some conclusions can be drawn, such as the addition of hemin may promote the conversion of some G-quadruplexes from antiparallel structures to parallel structures; the formation of G-quadruplexes is a crucial factor in determining the peroxidase activity of G-quadruplex-hemin complexes; and the complexes formed by hemin and parallel G-quadruplexes have much higher peroxidase activity than those formed by hemin and antiparallel G-quadruplexes.