Speeding up a single-molecule DNA motor with a simple catalyst

TL;DR

This paper introduces a simple catalytic method to accelerate a single-molecule DNA motor by preventing a key folding barrier, effectively doubling the restoration rate without affecting the motor's straightening process.

Contribution

The study presents a novel catalytic strand that inhibits folding of the fuel strand, significantly speeding up the DNA motor cycle and demonstrating robust, cycle-independent performance.

Findings

Catalyst doubles the restoration speed of the DNA motor.

The catalytic effect remains stable over multiple cycles.

Experimental results align with a model involving intermediate products.

Abstract

We demonstrate a catalytic control method for speeding up the single-molecule DNA motor introduced by Li and Tan [Nano Lett. {\bf 2}, 315 (2002)]. A key rate-limiting barrier in the reaction part of the cycle is the tendency for the second fuel strand $B$ to fold into the chair-like configuration of the original motor strand $M$. This seriously impedes the restoration reaction. We have designed a catalytic strand to inhibit the folding of $B$. Introduction of the catalyst speeds up the restoration reaction by roughly a factor of 2. The catalyst shows robust behavior for more than one cycle. The experimental data can be understood with a model with intermediate products. This technique provides dynamic control of the restoration rate of the motor without affecting the straightening rate.