Conjugation of hemin to G-quadruplex forming oligonucleotide using click chemistry

July 28, 2017

Title

Conjugation of hemin to G-quadruplex forming oligonucleotide using click chemistry

Author

J. Kosman, A. Stanislawska, A. Gluszynska, B. Juskowiak

Year

2017

Journal

International Journal of Biological Macromolecules

Abstract

Peroxidase-mimicking DNAzyme is one of the systems that recently gained a great interest. It has been successfully applied for designing numerous bioassays. The success of this system is connected to its advantages over a protein enzyme, horseradish peroxidase. Promising strategy for further improvement of performance of DNAzyme with peroxidase-like activity was proposed recently. It was based on the covalent attachment of hemin moiety to the G-quadruplex scaffold. We report here the first attempt of conjugating hemin to the G-quadruplex DNA using click chemistry approach. We modified hemin molecule through attachment of an azide-terminated linker to the porphyrin carboxylic group. Two click chemistry approaches were examined to conjugate the azide-modified hemin to a G-quadruplex oligonucleotide: copper-catalyzed and Cu-free cycloaddition reactions. Using Cu-free click reaction, we successfully synthesized G-quadruplex-hemin conjugate that exhibited promising peroxidase activity.

Instrument

J-1500

Keywords

Circular dichroism, DNA structure, Ligand binding, Thermal stability, Thermodynamics, Biochemistry