title: On the use of iron octa-alkylporphyrins as models for protoporphyrin IX-containing heme systems in studies employing magnetic circular dichroism spectroscopy.
abstract: The magnetic circular dichroism (MCD) properties of numerous oxidation and ligation state derivatives of myoglobin and horseradish peroxidase reconstituted with an iron octa-alkylporphyrin (mesoheme IX) have been investigated in order to establish the utility of such porphyrins as models for protoporphyrin IX-containing systems. The MCD spectra of the mesoheme-reconstituted proteins are blue-shifted (4-12 nm) and are somewhat more intense (1.5-2.5 fold) when compared to the spectra of analogous derivatives of native myoglobin and horseradish peroxidase. However, the spectral band patterns of the mesoheme-reconstituted proteins closely resemble those of the native proteins in essentially all cases. These data demonstrate that octa-alkylporphyrins can be productively used as models for protoporphyrin IX in studies of heme proteins with MCD spectroscopy.
authors.affiliation: Department of Chemistry and Biochemistry, School of Medicine, University of South Carolina, Columbia 29208.
authors.forename: J H
authors.initials: JH
authors.lastname: Dawson
authors.forename: S
authors.initials: S
authors.lastname: Kadkhodayan
authors.forename: C
authors.initials: C
authors.lastname: Zhuang
authors.forename: M
authors.initials: M
authors.lastname: Sono
mesh_terms: D000818:Animals; D002942:Circular Dichroism; D006418:Heme / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D006736:Horses; D008280:Magnetics; D008652:Mesoporphyrins / Q000737:chemistry*; D009211:Myoglobin / Q000737:chemistry; D011524:Protoporphyrins / Q000737:chemistry*; D014907:Whales
chemical_list: D008652:Mesoporphyrins; D009211:Myoglobin; D011524:Protoporphyrins; D006418:Heme; C031468:mesoporphyrin IX; C028025:protoporphyrin IX; D006735:Horseradish Peroxidase