Ferroheme undecapeptide

Figure 8. Absorption spectrum of ferriheme undecapeptide (—) and of ferroheme undecapeptide (hemochromogen) (- ) in 0.05 M sodium tetraborate, pH 9. The right-hand ordinate is for the Soret (y) band and for the absorbances at wavelengths shorter than 210 nm. The hemochromogen bands are labelled a-s. As there are no residues in the undecapeptide with chromophores absorbing at wavelengths greater than 240 nm, the 280 nm, e and S bands are clearly due to the heme chromophore. Reproduced, with permission, from [11],...

Figure 36. Circular dichroism of the Soret (y) band of the ferroheme undecapeptide. Dotted curve, in the presence of imidazole which causes hemes to dissociate with a resulting monomer spectrum that is a simple near-Gaussian curve. The dashed and solid curves are at different stages of association and show at least three bands within the envelope of the simple appearing absorption spectrum (upper curve), which is plotted with respect to the right ordinate. Reproduced, with permission, from [16].

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