High-spin ferric proteins

Yang, A.-S. and B. J. Gaffney (1987). Determination of relative spin concentration in some high-spin ferric proteins using E/D distribution in electron paramagnetic resonance simulations. Biophys. J. 51 55-67. 

Figure 11. The reduction of dihistidine hemichrome of hemoglobin H as studied by EPR The features of the EPR absorption derivative, labelled gx, gy, and gt, arise from the hemichrome. The feature at g = 2 is the high field end of the EPR spectrum of the high-spin ferric protein not yet converted to hemichrome.

Table 1. References for Representative High-Spin Ferric Proteins Characterized by EPR, X-Ray Structure, and Calculation...

In high-spin ferric iron this a-valuc is the result of the Fermi contact interaction alone. Hence, this a-value comprises an experimental determination of the Fermi contact interaction of the ferric iron in this protein. The value of —2gsPPx is, by the above procedure, equal to... 

Electronic absorption maxima for LIP, MnP, horseradish peroxidase (HRP) and various llganded forms of these enzymes are shown in Table I. The spectra of native LIP and MnP are characteristic of high-spin ferric heme proteins, with Soret and visible maxima ( 407, 502 and... 

---