Vishwanath, CK and Easwaran, KRK (1982) Circular dichroism and nuclear magnetic resonance studies on the complexation of valinomycin with calcium. In: Biochemistry, 21 (11). pp. 2612-2621.
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Complexation of valinomycin (VM) with the divalent cation Ca2+ in a lipophilic solvent, acetonitrile (CH3-CN), has been studied by using circular dichroism and proton and carbon- 13 nuclear magnetic resonance (‘H NMR and I3C NMR). From analyses of the spectral data, it is concluded that VM forms a 2:l (peptideion-peptide) sandwich complex with Ca2+, at low concentration of VM. At moderate conocentrations of the salt, in addition to the sandwich complex, an equimolar (1:l) complex different from those observed for potassium and sodium is also observed. At very large concentrations of the calcium salt, the data suggested a complex with a conformation similar to that of the free VM in polar solvents. Possible conformations for the sandwich and the equimolar VM-calcium complexes are proposed.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to American Chemical Society.|
|Department/Centre:||Division of Biological Sciences > Molecular Biophysics Unit|
|Date Deposited:||22 Jul 2009 07:11|
|Last Modified:||19 Sep 2010 05:38|
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