How Proximal Nucleobases Regulate the Catalytic Activity of G-Quadruplex/Hemin DNAzymes

0501656 - BFÚ 2019 RIV US eng J - Journal Article
Chen, J. - Zhang, Y. - Cheng, M. - Guo, Y. - Šponer, Jiří - Monchaud, D. - Mergny, Jean-Louis - Ju, H. - Zhou, J.
How Proximal Nucleobases Regulate the Catalytic Activity of G-Quadruplex/Hemin DNAzymes.
ACS Catalysis. Roč. 8, č. 12 (2018), s. 11352-11361. ISSN 2155-5435. E-ISSN 2155-5435
R&D Projects: GA ČR(CZ) GA16-13721S; GA MŠMT EF15_003/0000477
Institutional support: RVO:68081707
Keywords : repair thymine dimers * peroxidase-activity * activity enhancement * binding-site
OECD category: Physical chemistry
Impact factor: 12.221, year: 2018

G-quadruplexes (G4s) are versatile catalytic DNAs when combined with hemin. Despite the repertoire of catalytically competent G4/hemin complexes studied so far, little is known about the detailed catalytic mechanism of these biocatalysts. Herein, we have carried out an in-depth analysis of the hemin binding site within the G4/hemin catalysts, providing the porphyrinic cofactor with a controlled nucleotidic environment. We intensively assessed the position-dependent catalytic enhancement in model reactions and found that proximal nucleobases enhance the catalytic ability of the G4/hemin complexes. Our results allow for revisiting the mechanism of the G4/hemin-based catalysis, especially gaining insights into the rate-limiting step, demonstrating how both the G4 core and the proximal nucleotides dA and/or dC concomitantly activate the Compound 0> 0* prototropic cleavage of H2O2 to foster Compound 1 formation. These results provide mechanistic clues as to how the properties of G4-based catalysts can be improved to ultimately make them competitive with proteinaceous enzymes.
Permanent Link: http://hdl.handle.net/11104/0293649