Biomimetic Iron Complex Achieves TET Enzyme Reactivity*

Area of Science:

• Biochemistry
• Organic Chemistry
• Epigenetics

Background:

• 5-methyl-2'-deoxycytidine (5mdC) is a prevalent DNA epigenetic marker.
• Active DNA demethylation involves oxidation by Ten-Eleven Translocation (TET) enzymes.
• Synthetic iron(IV)-oxo complexes can model TET activity.

Purpose of the Study:

• To investigate the biomimetic activity of a synthetic iron(IV)-oxo complex ([FeIV(O)(Py5Me2H)]2+) as a TET enzyme model.
• To determine the reactivity of the complex towards 5-methyl cytosine (5mC) in nucleosides and oligonucleotides.
• To identify preferred oxidation sites and potential side reactions.

Main Methods:

• High-performance liquid chromatography (HPLC) and mass spectrometry (MS) techniques.
• Oxidation reactions using the synthetic iron(IV)-oxo complex.
• Analysis of reaction products from nucleosides and oligonucleotide strands.

Main Results:

• The iron complex selectively oxidized the 5-position of 5-methyl cytosine (5mC).
• Nucleosides and short oligonucleotide strands were confirmed as substrates.
• Side reactions, primarily at the anomeric center (1'), were observed but were minimal, especially in oligonucleotides.

Conclusions:

• The synthetic iron complex effectively biomimics TET enzyme activity on 5-methyl cytosine.
• The complex shows high selectivity for the target 5mC modification in DNA building blocks.
• This biomimetic approach offers insights into DNA demethylation mechanisms.