Dynamics and Control of a Quasi-1D Spin System

We study experimentally a system comprised of linear chains of spin-1/2 nuclei that provides a test-bed for multi-body dynamics and quantum information processing. This system is a paradigm for a new class of quantum information devices that can perform particular tasks even without universal control of the whole quantum system. We investigate the extent of control achievable on the system with current experimental apparatus and methods to gain information on the system state, when full tomography is not possible and in any case highly inefficient

A guide to quantifying membrane protein dynamics in lipids and other native-like environments by solution-state NMR spectroscopy

Recent biochemical and technical developments permit residue-specific solution NMR measurements of membrane protein (MP) dynamics in lipidic and chaperone-bound environments. This is possible by combinations of improved sample preparations with suitable NMR relaxation experiments to correlate protein function to backbone dynamics on timescales from picoseconds to seconds, even for large MP-lipid assemblies above 100 kDa in molecular mass. Here, we introduce the basic concepts of different NMR relaxation experiments, individually sensitive to specific timescales. We discuss the general limitations of detergent environments and highlight the importance for native-like environments when studying MPs. We then review three practical studies of fast- and slow-timescale MP dynamics in lipid environments, as well as in a natively unfolded, chaperone-bound state. These examples illustrate the new avenues solution NMR spectroscopy is taking to investigate MP dynamics in native-like environments with atomic resolution

Two-dimensional rotational spin-echo nuclear magnetic resonance in solids: correlation of chemical shift and dipolar interactions

Two-dimensional NMR techniques which sep. the chem. shift and heteronuclear dipolar interactions were applied to samples spinning at the magic angle. Because of the inhomogeneous nature of the 2 interactions, rotational echoes were obsd. in the time domain of each dimension. The corresponding Fourier transforms yield rotational sideband spectra which provide information on the principal values and relative orientations of the shift and dipolar tensors, and from the latter, internuclear distances may be calcd. The techniques therefore provide a means for obtaining structural data, for example, 13C-1H and 15N-1H distances, in powder samples. [on SciFinder (R)