Helix-Coil Kinetics of Individual Polyadenylic Acid Molecules in a Protein Channel

摘要

Helix-coil transition kinetics of polyadenylic acid [poly(A)] inside a small protein channel is inves-ntigated for the first time, at the single molecule level. The confinement of a RNA molecule inside thenchannel slows its kinetics by nearly 3 orders of magnitude as compared to bulk measurements of freenpoly(A). These findings are related to the interaction energy of the RNA structure with the interior of thenpore, explained by a simple two-state model. These results shed light on the way intermolecularninteractions alter nucleic acid kinetics.