Solution NMR investigation of the response of the lactose repressor core domain dimer to hydrostatic pressure.
Related Articles Solution NMR investigation of the response of the lactose repressor core domain dimer to hydrostatic pressure.
Biophys Chem. 2017 Feb 24;:
Authors: Fuglestad B, Stetz MA, Belnavis Z, Joshua Wand A
Abstract
Previous investigations of the sensitivity of the lac repressor to high-hydrostatic pressure have led to varying conclusions. Here high-pressure solution NMR spectroscopy is used to provide an atomic level view of the pressure induced structural transition of the lactose repressor regulatory domain (LacI* RD) bound to the ligand IPTG. As the pressure is raised from ambient to 3kbar the native state of the protein is converted to a partially unfolded form. Estimates of rotational correlation times using transverse optimized relaxation indicates that a monomeric state is never reached and that the predominate form of the LacI* RD is dimeric throughout this pressure change. Spectral analysis suggests that the pressure-induced transition is localized and is associated with a volume change of approximately -115mlmol(-1) and an average pressure dependent change in compressibility of approximately 30mlmol(-1)kbar(-1). In addition, a subset of resonances emerge at high-pressures indicating the presence of a non-native but folded alternate state.
PMID: 28249763 [PubMed - as supplied by publisher]
More...