ISSN:
0749-1581
Keywords:
NMR
;
1H NMR
;
113Cd NMR
;
Metallothionein Blue crab
;
Callinectes sapidus
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Metallothionein is a cysteine-rich metal-binding protein whose biosynthesis is closely regulated by the level of exposure of an organism to zinc, copper, cadmium, etc., metal salts. The metallothionein from the crab Callinectes sapidus is known to bind six divalent metal ions. The 113Cd NMR spectrum of the 113Cd—substituted protein shows six distinct 113Cd resonances spanning a chemical shift range of 620-665 ppm, indicating the presence of six distinct tetrahedrally coordinated divalent metal ion binding sites. Heteronuclear 1H—113Cd correlation experiments revealed all the metal-to-cysteine connectivities present in this protein and the 2X(2113Cd)-;filtered COSY experiment revealed that six cysteines are involved in the ligation of two Cd2+ ions. Additionally, following the complete sequential resonance assignment of the 1H NMR data, the two separate Cd3Cys9 metal binding clusters can be shown to reside in two distinct protein domains.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260311319
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