Figure 4: Thermal stability analysis for the Lig4 C-ter domain and XRCC4 constructs alone or in complex by Differential Scanning Fluorimetry (DSF) and analysis of the interaction of selected compounds with the Lig4-Cter domain by DSF and Saturation Transfer Difference -NMR spectroscopy.
From: Structure-Based Virtual Ligand Screening on the XRCC4/DNA Ligase IV Interface
(A). Unfolding was followed with 10X SYPRO Orange dye and between 20 and 89 °C. Fluorescence signal derivative was plotted against the temperature and Tm values were estimated from the transition midpoint of the fluorescence curves. (B) Analyis by DSF of the thermal stability of the Lig4 C-ter domain in the presence of selected compounds or DMSO, as indicated. Unfolding is followed with 10X SYPRO Orange dye and between 20 and 89 °C. Tm values are estimated from the transition midpoint of the fluorescence curve (mean ± SD, n = 3). (C,D) One-dimensional 1H (a) and 1H STD-NMR spectra of the two molecules 3101 and 231 alone (b) or in association with the Lig4 C-ter fragment (c). Protons making close contacts with the protein show significant resonance intensity enhancements. Due to baseline distortion and buffer, only the aromatic regions are represented. Each corresponding proton is assigned on the spectrum and labeled on the molecule.
