1H-NMR sequential assignments and cation-binding studies of spinach plastocyanin.
The essentially complete assignment of the 1H-NMR spectrum of the Cu(i) form of spinach plastocyanin has been achieved using two-dimensional NMR techniques and sequence-specific resonance assignment procedures. A variety of pH and temperature conditions was utilised to overcome the problems of resonance overlap in the spectrum, degeneracy of C alpha H and solvent H2O chemical shifts, and cross-saturation of labile NH resonances. A qualitative analysis of the long-range nuclear Overhauser effects observed indicates that the backbone fold of spinach plastocyanin is very similar to that of poplar plastocyanin, whose structure has been solved by X-ray crystallography and differs in 22 of its 99 amino acid residues. The assignments provide a basis for further investigations into the structural and ion- and protein-binding properties of plastocyanin in solution.
Inorganic Chemistry Laboratory, University of Oxford, England.
P C
PC
Driscoll
H A
HA
Hill
C
C
Redfield
D001665:Binding Sites; D002412:Cations; D006859:Hydrogen; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D010970:Plastocyanin / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D013045:Species Specificity
D002412:Cations; D010940:Plant Proteins; D006859:Hydrogen; D010970:Plastocyanin