Kinetic and thermodynamic control of g-quadruplex folding

A matter of speed: When allowed to fold in a K(+) /poly(ethylene glycol) solution, the guanine?(G)-rich strand of vertebrate telomere DNA forms a parallel/antiparallel G-quadruplex, which is a (3+1) hybrid, within microseconds before slowly transforming into the parallel one within hours. Thus, the conformation that a G-quadruplex initially adopts under physiological conditions may not be the one it adopts at the equilibrium state.