Volumetric analysis of formation of the complex of G-quadruplex DNA with hemin using high pressure.

Volumetric analysis of formation of the complex of G-quadruplex DNA with hemin using high pressure. J Inorg Biochem. 2016 Sep 2; Authors: Takahashi S, Bhowmik S, Sugimoto N Abstract DNA guanine-quadruplexes (G-quadruplexes) complexed with the Fe-containing porphyrin, hemin (iron(III)-protoporphyrin IX), can catalyze oxidation reactions. This so-called DNAzyme has been widely used in the field of DNA nanotechnology. To improve DNAzyme properties, we sought to elucidate the interaction mechanism between G-quadruplex DNA and hemin. Here, we performed volumetric analyses of formation of the complex between an oligonucleotide with the sequence of human telomeric DNA (h-telo) and hemin. The G-quadruplex DNA alone and the G-quadruplex DNA-hemin complex were destabilized with increasing pressure in Na(+) buffer. The pressure required to destabilize the h-telo-hemin complex was less in K(+)-containing buffer than in buffer with Na(+), which indicates that there was a smaller volumetric change upon h-telo formation in K(+) buffer than in Na(+) buffer. The calculated change in h-telo-hemin binding volume (∆Vb) in the Na(+) buffer was 2.5mLmol(-1), whereas it was -41.7 in mLmol(-1) the K(+) buffer. The DNAzyme activity in the K(+) buffer was higher than that in the Na(+) buffer at atmospheric pressure. Interestingly, the pressure effect on the destabilization of the h-telo-hemin complex in the presence of poly(ethylene glycol)200 (PEG200) was ...
Source: Journal of Inorganic Biochemistry - Category: Biochemistry Authors: Tags: J Inorg Biochem Source Type: research