Cover Story 2015, Volume 6 Issue 6
G-quadruplex is a significant drug target for inhibiting telomerase maintenance of telomeres in cancer, and metal cations play important roles in stabilizing G-quadruplex. To investigate the detailed binding procedures, molecular dynamics simulations were conducted on the hybrid [3+1] form-one human telomeric intra-molecular G-quadruplex. We show here that the binding of a potassium ion to a G-tetrad core is mediated by two alternative pathways. Principal component analysis illustrated the dominant concerted motions of G-quadruplex occurred at the loop domains. MM-PBSA calculations revealed that binding was energetically favorable and driven by the electrostatic interactions. The lower binding site was found more constructive favorable for binding. Our data provide useful information on a potassium-mediated stable structure of human telomeric intra-molecular G-quadruplex, implicating in ion disorder associated conformational changes and targeted drug design.[Detail] ...