Guanidinium‐Modified Phthalocyanines as High‐Affinity G‐Quadruplex Fluorescent Probes and Transcriptional Regulators

Abstract

Fluorescence is ON and transcriptional control is OFF when the guanidinium-modified zinc phthalocyanine Zn-DIGP binds a G-quadruplex DNA from the c-Myc promoter. With an equilibrium dissociation constant Kd of less than 2 nM, this interaction is the strongest binding interaction between a G-quadruplex structure and a small molecule reported to date.