Multicenter metalloproteins

There may, however, be specific reasons to study a signal over an extended temperature range. For one, a linear increase in EPR amplitude with the inverse of the temperature (Curie s law) is proof that a spin system is a two-level system, i.e., an S = 1/2 or an effective S = 1/2 system. More importantly, in complex multicenter metalloproteins, overlapping spectra may be deconvoluted by virtue of their Tu value being different if two centers, a and b, have rMa < TMb then at TMb the spectrum of center a is broadened and that of center b is not. It is once more emphasized that these types of studies require determination of (anisotropic) saturation behavior at all relevant temperatures. 

Hagen, W.R., Hearsen, D.O., Harding, L.J., and Dunham, W.R. 1985d. Quantitative numerical analysis of g strain in the EPR of distributed systems and its importance for multicenter metalloproteins. Journal of Magnetic Resonance 61 233-244. 

Magnetic susceptibility studies can be difficult to interpret for multicentered metalloproteins particularly when paramagnetic impurities are present, whereas with MCD spectroscopy the magnetic properties of individual centers can be investigated independently. However, it should be emphasized that MCD studies... 

Cytochrome C4 A Prototype for Microscopic Electronic Mapping of Multicenter Redox Metalloproteins... 

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