ISSN:
1573-5001
Keywords:
J coupling
;
113Cd
;
199Hg
;
Rubredoxin
;
Hydrogen bonding
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary A method is described for measurement of small unresolvable heteronuclear J couplings. The method is based on quantitative analysis of a phase-purged heteronuclear spin-echo difference spectrum, and is demonstrated for measuring1H-113Cd and1H-199Hg J couplings in metal-substituted rubredoxin (Mr ∼ 5.4 kDa) fromPyrococcus furiosus. Couplings from cadmium to backbone amide protons that are hydrogen bonded to the Cys-S atoms directly bonded to Cd vary from smaller than 0.3 to 1.8 Hz; a ‘through-space’ coupling between Cd and the protons of an alanine methyl group was measured to be 0.3 Hz. Couplings to199Hg are significantly larger and fall in the 0.4–4 Hz range.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02192814