Simultaneous determination of hemes a, b, and c from pyridine hemochrome spectra

doi:10.1016/0003-2697(87)90643-9

Analytical Biochemistry

Volume 161, Issue 1, 15 February 1987, Pages 1-15

https://doi.org/10.1016/0003-2697(87)90643-9 Get rights and content

Abstract

Two procedures for analyzing overlapping optical spectra of mixtures of pyridine hemochromes are described, and extinction coefficients of pyridine hemochromes are provided for use with these methods. In the first procedure, absorbance is measured at a number of wavelengths equal to the number of components to be analyzed. This is the minimum amount of spectral data from which the concentration of each species can be calculated. In the second procedure, absorbance is measured at a number of wavelengths greater than the number of components to be analyzed. This redundancy of information makes it impossible to fit spectra which contain contributions from additional components, unless the spectra of the additional components are equal to linear combinations of the spectra of the species being analyzed. These two procedures are generally applicable to analyses of absolute or difference spectra of mixtures of components obeying Beer's law. The sensitivity to error in the absorbance measurements is only slightly greater than that for measuring a pure component at a single wavelength.

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^☆: A hemochrome is defined as a complex of ferroporphyrin with a nitrogenous base. If the iron is in the ferric state the compound is a hemichrome (24). However, to avoid repetition of “hemichrome or hemochrome,” we have used the term hemochrome loosely to refer to nitrogenous complexes of iron-porphyrin without respect to the oxidation state of the iron. This is analogous to use of the term “heme” as in “heme proteins” without respect to oxidation state, as “heme” strictly refers to the reduced moiety.

²: Current address: University of Illinois at Urbana-Champaign, Department of Physiology and Biophysics, 524 Burrill Hall, 407 S. Goodwin Avenue, Urbana, IL 61801.

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Simultaneous determination of hemes a, b, and c from pyridine hemochrome spectra☆

Abstract

Arch. Biochem. Biophys

Biochim. Biophys. Acta

Biochim. Biophys. Acta

Biochim. Biophys. Acta

Biochim. Biophys. Acta

J. Biol. Chem

Biochim. Biophys. Acta

Biochim. Biophys. Acta

J. Biol. Chem

Anal. Biochem

J. Biol. Chem