An introduction to MAS NMR spectroscopy on oriented membrane proteins
✍ Scribed by Glaubitz, Clemens
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 253 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1043-7347
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✦ Synopsis
Membrane proteins are a major challenge for structural biology. The membrane adds an important constraint to their structure, which makes it necessary not only to obtain distance but also orientational information. Solid-state NMR on oriented immobile molecular systems provides information for relative orientations of labelled molecular groups within proteins and with respect to the membrane plane. If oriented samples are subject to rotation about the magic angle in the magnetic field, with rates slower than the dominating inhomogeneous, anisotropic NMR interactions, the observed spectrum will consist of a set of narrow spinning sidebands. Their intensities are orientationally dependent and thereby a tool to obtain structural information. This approach is demonstrated and explained using a deuterated methyl group in oriented bacteriorhodopsin, a membrane-bound protein acting as a light-driven proton pump. This is a typical example for an immobile distribution in a noncrystalline biological sample having cylindrical symmetry. Advantages, practical aspects, and general perspective of magic angle spinning on oriented proteins are presented.