Poly(G)

Poly (G) (Polyguanylic acid) is a high-molecular-weight synthetic ribopolynucleotide. In the presence of Na⁺ or K⁺ ions, Poly (G) undergoes time-dependent structural modification, gradually self-assembling from a single strand into large G-quadruplex aggregates. Poly (G) undergoes cooperative secondary structure dissociation under alkaline conditions, but its secondary structure can withstand high temperatures up to 100°C and is resistant to snake venom diesterase at low Na⁺ concentrations. Poly (G) forms stable 1:1 complexes with polycytidylic acid or poly 5-bromocytidylic acid, but does not bind to polyinosinic acid or polyadenylic acid. Poly (G) can be applied to studies on the interactions between drugs and G-rich DNA fragments in electrochemical biosensors^[1][2].