Stellacyanin, Umecyanin, and Mung Bean Blue Protein

Stellacyanin, Umecyanin, and Mung Bean Blue Protein 

The ligands of Cu2+ bound to stellacyanin have been probed with the electron nuclear double resonance (ENDOR) technique by Rist et al. 28). These authors have drawn the following conclusions about the immediate structure of the Cu2+ complex of stellacyanin (a) It is not readily accessible to solvent water molecules, consistent with previous observations of Peisach et al. 24) (b) More than one set of N-atoms contributes to the ENDOR signal and (c) The unpaired electron of the Cu2+ ion is quite strongly coupled to at least one proton in the oxidized protein which in the native oxidized form is not readily exchangeable with solvent protons. 

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