Secondary structure and hydrogen bonding of crambin in solution. A two-dimensional NMR study.
The secondary structure of crambin in solution has been determined using two-dimensional NMR and is found to be essentially identical to that of the crystal structure. The H-D exchange of most amide protons can be accounted for in terms of the hydrogen bonds found in the X-ray structure. Exceptions are the amide protons of Cys-4 and Ser-6, which exchange more slowly than expected, and of Asn-46 for which the exchange is faster. These results might be explained by a slightly different conformation of the C-terminal region of the protein in solution. The slow exchange of the amides of Cys-32 and Glu-23 might be due to aggregation involving an extremely hydrophobic part of the protein in solution.
Lamerichs
R M
RM
Department of Organic Chemistry, University of Utrecht, The Netherlands.
Berliner
L J
LJ
Boelens
R
R
De Marco
A
A
Llinàs
M
M
Kaptein
R
R
D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D010940:Plant Proteins; D011487:Protein Conformation; D012996:Solutions
D010940:Plant Proteins; D012996:Solutions; C024934:crambin protein, Crambe abyssinica