On the use of iron octa-alkylporphyrins as models for protoporphyrin IX-containing heme systems in studies employing magnetic circular dichroism spectroscopy.
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.
Dawson
J H
JH
Department of Chemistry and Biochemistry, School of Medicine, University of South Carolina, Columbia 29208.
Kadkhodayan
S
S
Zhuang
C
C
Sono
M
M
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
D008652:Mesoporphyrins; D009211:Myoglobin; D011524:Protoporphyrins; D006418:Heme; C031468:mesoporphyrin IX; C028025:protoporphyrin IX; D006735:Horseradish Peroxidase