Octameric G8 c-di-GMP is an efficient peroxidase and this suggests that an open G-tetrad site can effectively enhance hemin peroxidation reactions

Abstract

G-Quadruplex forming structures continue to be utilized for many biotechnological applications. Many parallel and mixed topology G-quadruplexes enhance the catalytic proficiency of hemin and there is an increasing trend to use these as non-protein-based peroxidase. Until now, the most proficient of nucleotide-based peroxidases have been oligonucleotides (DNA/RNA) that contain two or more G-tetrad planes and loop sequences. Herein we present a new “loopless” small molecule-based peroxidase, comprised of bis-(3′,5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) octamer, capable of enhancing hemin peroxidation to the same extent as other well-known DNA peroxidases. Secondly, we reveal that the carboxylate moieties of hemin, the co-factor for nucleic acid-based catalysts, are important for catalysis because the replacement of the anionic carboxylate groups of hemin with ammonium moieties results in a decrease in peroxidation.