https://www.cell.com/cell/pdf/S0092-8674(12)01554-1.pdf

Conformational Coupling across the Plasma Membrane in Activation of the EGF Receptor.

https://carman.hms.harvard.edu/PDFs/Xu_Cell_2008.pdf

Regulation of T Cell Receptor Activation by Dynamic Membrane Binding of the CD3ɛ Cytoplasmic Tyrosine-Based Motif

The use of residual dipolar couplings (RDCs) in the analysis of biomolecular structure and dynamics has expanded rapidly since its potential as a source of structural information on proteins was demonstrated in the mid 1990s.1,2 Of course, this work on proteins rested on applications to smaller biomolecular systems that occurred much earlier,3 and even these early applications benefited from prior research on organic molecules in partially ordered liquid crystals.4 However, in the 1990s, the existence of efficient means of introducing magnetically active isotopic labels (13C and 15N) and the availability of triple resonance strategies for selective manipulation and assignment of NMR resonances made widespread application to large biomolecules possible. It was fortuitous that the 13C and 15N labels introduced had small magnetogyric ratios, allowing simple dipolar interactions with directly bonded protons to dominate RDC observations. Prior work had focused on systems with couplings coming from the much larger 1H-1H dipolar and 2H quadrupolar interactions. While large interactions and the resultant increased size of observable couplings may have seemed an advantage, these large interactions also lead to complex spectra and broader lines. In the case of 1H1H interactions, additional splittings of resonances from protons at long distances arose, and in both cases broader lines resulted from enhanced spin relaxation processes. Since the recognition of the potential of RDCs in protein structure determination, applications have spread to nucleic acid structure, carbohydrate structure, protein-ligand interactions, protein domain relationships, high-throughput strategies for structural genomics, and studies of motional amplitudes in flexible assemblies. Related pieces of data coming from interactions with paramagnetic sites and chemical shift anisotropy (CSA) offsets have also come onto the scene. Each new application demands parallel improvements in sample preparation, data acquisition, and data analysis methods. The development of RDC applications has been reviewed periodically since their introduction to the structural biology field,5-13 and the reader is referred to these reviews for a more complete description of the history and the underlying theory. Here, we will provide a brief introduction to RDCs and related data as they are used today. Advances that have been made in alignment techniques, data acquisition techniques, and analysis methods will be reviewed. In the course of this review, we will provide examples of applications that use these methods. Applications, per se, have become too numerous to attempt a comprehensive review. * To whom correspondence should be addressed. James H. Prestegard, Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA, 30602. Phone: (706) 542-6281. Fax: (706) 542-4412. E-mail: jpresteg@ccrc.uga.edu. † University of Georgia. ‡ Institut de Biologie Structurale. 3519 Chem. Rev. 2004, 104, 3519−3540

http://www.cs.duke.edu/brd/Teaching/Bio/asmb/current/2papers/NMR/Residual-dipolar-coupling/prestegard-review04.pdf

Residual Dipolar Couplings in Structure Determination of Biomolecules

Acoustically active liposomes for drug encapsulation and ultrasound-triggered release.

Surfactants are surface-active, amphiphilic compounds that are water-soluble in the micro- to millimolar range, and self-assemble to form micelles or other aggregates above a critical concentration. This definition comprises synthetic detergents as well as amphiphilic peptides and lipopeptides, bile salts and many other compounds. This paper reviews the biophysics of the interactions of surfactants with membranes of insoluble, naturally occurring lipids. It discusses structural, thermodynamic and kinetic aspects of membrane-water partitioning, changes in membrane properties induced by surfactants, membrane solubilisation to micelles and other phases formed by lipid-surfactant systems. Each section defines and derives key parameters, mentions experimental methods for their measurement and compiles and discusses published data. Additionally, a brief overview is given of surfactant-like effects in biological systems, technical applications of surfactants that involve membrane interactions, and surfactant-based protocols to study biological membranes.

Interactions of surfactants with lipid membranes.

Structural evaluation of phospholipid bicelles for solution-state studies of membrane-associated biomolecules.

Environmentally significant materials including soils, plant tissues, melanin pigments, and urban surface films possess swollen or swellable constituents that are not studied ideally using either solution- or solid-state NMR. Beginning in the 1970s and accelerating during the past 15 years, high-resolution (HR)-MAS techniques have been developed to study these challenging materials, yielding unprecedented molecular detail and informing mechanistic hypotheses. This valuable information has been forthcoming without the need for soil or tissue extraction, and without subjecting the macromolecular entities of interest to chemical degradation. In this overview, we focus on practical HR-MAS NMR strategies, including both methodological fundamentals and illustrative architectural findings for soil organic matter, plant protective polymers and biomass, and ultraviolet-resistant melanin pigments. In addition to the acquisition of one-dimensional spectra tailored for mobile or immobilized constituents of whole soils, we illustrate the use of HR-MAS in conjunction with two-dimensional NMR experiments [COSY, TOCSY, heteronuclear multiple-quantum coherence (HMQC), and heteronuclear multiple-bond correlation (HMBC)] to elucidate the macromolecular chemistry of terrestrial plant litter decomposition and environmental stress resistance at plant surfaces.

Guohua Wu

Papers

Structural evaluation of phospholipid bicelles for solution-state studies of membrane-associated biomolecules.

Environmental NMR: High‐resolution Magic‐angle Spinning