title: Pulsed pressure perturbations, an extra dimension in NMR spectroscopy of proteins.
abstract: The introduction of multidimensional NMR spectroscopy was a breakthrough in biological NMR methodology because it allowed the unequivocal correlation of different spin states of the system. The introduction of large pressure perturbations in the corresponding radio frequency (RF) pulse sequences adds an extra structural dimension into these experiments. We have developed a microprocessor-controlled pressure jump unit that is able to introduce fast, strong pressure changes at any point in the pulse sequences. Repetitive pressure changes of 80 MPa in the sample tube are thus feasible in less than 30 ms. Two general forms of these experiments are proposed here, the pressure perturbation transient state spectroscopy (PPTSS) and the pressure perturbation state correlation spectroscopy (PPSCS). PPTSS can be used to measure the rate constants and the activation energies and activation volumes for the transition between different conformational states including the folded and unfolded state of proteins, for polymerization-depolymerization processes, and for ligand binding at atomic resolution. PPSCS spectroscopy correlates the NMR parameters of different pressure-induced states of the system, thus allowing the measurement of properties of a given pressure induced state such as a folding intermediate in a different state, for example, the folded state. Selected examples for PPTSS and PPSCS spectroscopy are presented in this Article.
authors.affiliation: Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Universitätsstrasse 31, D-93047 Regensburg, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Kremer
authors.forename: Martin
authors.initials: M
authors.lastname: Arnold
authors.forename: Claudia Elisabeth
authors.initials: CE
authors.lastname: Munte
authors.forename: Rainer
authors.initials: R
authors.lastname: Hartl
authors.forename: Markus Beck
authors.initials: MB
authors.lastname: Erlach
authors.forename: Joerg
authors.initials: J
authors.lastname: Koehler
authors.forename: Alexander
authors.initials: A
authors.lastname: Meier
authors.forename: Hans Robert
authors.initials: HR
authors.lastname: Kalbitzer
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D004867:Equipment Design; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000295:instrumentation*; D011312:Pressure; D011487:Protein Conformation; D017510:Protein Folding; D013210:Staphylococcus / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins