Studying Protein-DNA Dynamics and Protein Unfolding Using a Force-Free Single-Molecule Technique

Abstract

We are using optimized variations of a force-free single-molecule technique, known as Tethered Particle Motion (TPM) to study protein-DNA dynamics and protein folding/refolding in their natural form. First we use it to quantitatively describe how HU protein alters the DNA persistence length with regard to its concentration by locally bending or unbending different regions in the DNA and hence, changing the local flexibility of the DNA chain. A second variation of the TPM method enables us to track the folding and unfolding of single polypeptide chains composed of I27 tandem repeats using either chemical denaturation (force-free) or force unfolding using flow or AFM.