Hsa‐miR‐1587 G‐quadruplex formation and dimerization induced by NH4+, molecular crowding environment and jatrorrhizine derivatives

Publication date: 1 March 2018
Source:Talanta, Volume 179
Author(s): Wei Tan, Long Yi, Zhentao Zhu, Lulu Zhang, Jiang Zhou, Gu Yuan
A guanine-rich human mature microRNA, miR-1587, was discovered to form stable intramolecular G-quadruplexes in the presence of K⁺, Na⁺ and low concentration of NH4⁺ (25mM) by electrospray ionization mass spectrometry (ESI-MS) combined with circular dichroism (CD) spectroscopy. Furthermore, under high concentration of NH4⁺ (100mM) or molecular crowding environments, miR-1587 formed a dimeric G-quadruplex through 3′-to-3′ stacking of two monomeric G-quadruplex subunits with one ammonium ion sandwiched between the interfaces. Specifically, two synthesized jatrorrhizine derivatives with terminal amine groups could also induce the dimerization of miR‐1587 G‐quadruplex and formed 1:1 and 2:1 complexes with the dimeric G-quadruplex. In contrast, jatrorrhizine could bind with the dimeric miR‐1587 G‐quadruplex, but could not induce dimerization of miR‐1587 G‐quadruplex. These results provide a new strategy to regulate the functions of miR-1587 through induction of G-quadruplex formation and dimerization.

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