1. SIGNAL TRANSDUCTION. Structural basis for nucleotide exchange in heterotrimeric G proteins.

    Science 348(6241):1361 (2015) PMID 26089515 PMCID PMC4968074

    G protein-coupled receptors (GPCRs) relay diverse extracellular signals into cells by catalyzing nucleotide release from heterotrimeric G proteins, but the mechanism underlying this quintessential molecular signaling event has remained unclear. Here we use atomic-level simulations to elucidate t...
  2. Structural Insights into the Dynamic Process of β2-Adrenergic Receptor Signaling.

    Cell 161(5):1101 (2015) PMID 25981665 PMCID PMC4441853

    G-protein-coupled receptors (GPCRs) transduce signals from the extracellular environment to intracellular proteins. To gain structural insight into the regulation of receptor cytoplasmic conformations by extracellular ligands during signaling, we examine the structural dynamics of the cytoplasmi...
  3. Structure-relaxation mechanism for the response of T4 lysozyme cavity mutants to hydrostatic pressure.

    PNAS 112(19):E2437 (2015) PMID 25918400 PMCID PMC4434698

    Application of hydrostatic pressure shifts protein conformational equilibria in a direction to reduce the volume of the system. A current view is that the volume reduction is dominated by elimination of voids or cavities in the protein interior via cavity hydration, although an alternative mecha...
  4. Saturation Recovery EPR and Nitroxide Spin Labeling for Exploring Structure and Dynamics in Proteins.

    Methods in Enzymology 564:3 (2015) PMID 26477246

    Experimental techniques capable of determining the structure and dynamics of proteins are continuously being developed in order to understand protein function. Among existing methods, site-directed spin labeling in combination with saturation recovery (SR) electron paramagnetic resonance spectro...
  5. High-Pressure EPR and Site-Directed Spin Labeling for Mapping Molecular Flexibility in Proteins.

    Methods in Enzymology 564:29 (2015) PMID 26477247

    High hydrostatic pressure is a powerful probe of protein conformational flexibility. Pressurization reveals regions of elevated compressibility, and thus flexibility, within individual conformational states, but also shifts conformational equilibria such that "invisible" excited states become ac...
  6. Mapping protein conformational heterogeneity under pressure with site-directed spin labeling and double electron-electron resonance.

    PNAS 111(13):E1201 (2014) PMID 24707053 PMCID PMC3977274

    The dominance of a single native state for most proteins under ambient conditions belies the functional importance of higher-energy conformational states (excited states), which often are too sparsely populated to allow spectroscopic investigation. Application of high hydrostatic pressure increa...
  7. Circular dichroism and site-directed spin labeling reveal structural and dynamical features of high-pressure states of myoglobin.

    PNAS 110(49):E4714 (2013) PMID 24248390 PMCID PMC3856799

    Excited states of proteins may play important roles in function, yet are difficult to study spectroscopically because of their sparse population. High hydrostatic pressure increases the equilibrium population of excited states, enabling their characterization [Akasaka K (2003) Biochemistry 42:10...