ISSN:
0749-1581
Keywords:
1H NMR
;
NOESY
;
Methionine
;
Conformation
;
Cytochromes
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A complete relaxation matrix approach was used to determine the conformation of the Met ligand to the haem in Methylophilus methylotrophus cytochrome cH, including the configuration at the sulphur; the pattern of NOEs is shown to be dominated by spin diffusion at mixing times as short as 25 ms, rendering the two-spin approximation unreliable. The Met conformation, together with an analysis of aromatic proton resonances, indicates a structure almost identical with that found by x-ray crystallography for Pseudomonas aeruginosa cytochrome c551, which has a 45% similarity in sequence. The paramagnetic shifts of the haem methyl proton resonances in the oxidized protein support the view that the asymmetry in the electronic structure of the haem is dominated by the orientation of the Met ligand.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260311318
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