Protein conformation and proton nuclear-magnetic-resonance chemical shifts

Density functional calculation of nuclear magnetic resonance chemical shifts

A current-density functional theory for the calculation of nuclear magnetic resonance chemical shifts is presented. If the Kohn–Sham orbitals are expanded in a finite basis set, one of the main problems is the strong dependency of the results with respect to a shift of the gauge origin of the vector potential which describes the external magnetic field. Two computational schemes implementing bo...

Proton Nuclear Magnetic Resonance Spectroscopy

Proton nuclear magnetic resonance studies of isonitrile-heme protein complexes.

Steric interactions between bound ligand molecules and the valine E11 methyl groups of human hemoglobin and sperm whale myoglobin have been examined directly by high resolution NMR techniques. The methyl proton resonances of this amino acid are shifted markedly upfield and away from the bulk of the protein resonances by the shielding effect of circulating pi electrons in the porphyrin ring. We ...

Toward the quantum chemical calculation of nuclear magnetic resonance chemical shifts of proteins.

Despite the many protein structures solved successfully by nuclear magnetic resonance (NMR) spectroscopy, quality control of NMR structures is still by far not as well established and standardized as in crystallography. Therefore, there is still the need for new, independent, and unbiased evaluation tools to identify problematic parts and in the best case also to give guidelines that how to fix...

A proton nuclear magnetic resonance study of the conformation of bovine anaphylatoxin C5a in solution.

The solution conformation of bovine anaphylatoxin C5a has been investigated by nuclear magnetic resonance (NMR) spectroscopy. The 1H-NMR spectrum is assigned in a sequential manner using a variety of two-dimensional NMR techniques. A qualitative interpretation of the short range nuclear Overhauser enhancement data involving the NH, C alpha H and C beta H protons suggests that C5a has four helic...