Correlation between structure and spectroscopy of copper proteins

2 Correlation between structure and spectroscopy of copper proteins 

On the basis of the electronic, resonance Raman, and EPR spectra, the cysteine-containing copper proteins have been divided into four groups axial type 1 (e.g. plastocyanin), rhombic type 1 (e.g. nitrite reductase and stellacyanin), type 1.5, and type 2 (mutant) copper proteins [81]. We have studied the spectra of members of each group with the CASPT2 method [33,34,36,38]. 

The only protein that does not fit into the above description is stellacyanin. The structure of this protein is clearly trigonal, with a p angle of 84°, similar to plas-tocyanin. However, the ratio for stellacyanin is significantly higher than 

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