NMR Titration Studies in Z-DNA Dynamics

Chemical shift perturbation (CSP) is a simple NMR technique for studying the DNA binding of proteins. Titration of the unlabeled DNA into the ¹⁵N-labeled protein is monitored by acquiring a two-dimensional (2D) heteronuclear single-quantum correlation (HSQC) spectrum at each step of the titration. CSP can also provide information on the DNA-binding dynamics of proteins, as well as protein-induced conformational changes in DNA. Here, we describe the titration of DNA for the ¹⁵N-labeled Z-DNA-binding protein, monitored via 2D HSQC spectra. NMR titration data can be analyzed with the active B-Z transition model to provide the protein-induced B-Z transition dynamics of DNA.