Conformational fluctuations affect protein alignment in dilute liquid crystal media.
The discovery of dilute liquid crystalline media to align biological macromolecules has opened many new possibilities to study protein and nucleic acid structures by NMR spectroscopy. We inspect the basic alignment phenomenon for an ensemble of protein conformations to deduce relative contributions of each member to the residual dipolar coupling signals. We find that molecular fluctuations can affect the alignment and discover a resulting emphasis of certain conformations. However, the internal fluctuations are largely uncorrelated with those of the alignment, implying that proteins have liquidlike molecular surfaces. Furthermore, we consider the implications of a dynamic bias to structure determination using data from the weak alignment method.
Louhivuori
Martti
M
Department of Physical Sciences, Gustaf Hällströmin katu 2, University of Helsinki, Finland.
Otten
Renee
R
Lindorff-Larsen
Kresten
K
Annila
Arto
A
D006801:Humans; D008956:Models, Chemical; D008958:Models, Molecular; D009419:Nerve Tissue Proteins; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D013816:Thermodynamics; D019209:Troponin C / Q000737:chemistry; D025801:Ubiquitin / Q000737:chemistry
C029152:G-substrate; D009419:Nerve Tissue Proteins; D011506:Proteins; D019209:Troponin C; D025801:Ubiquitin