Correlations between Optical Rotatory Dispersion and Other Spectroscopic Properties of Ferricytochrome c (Horse Heart)

1971 ◽  
Vol 49 (4) ◽  
pp. 441-447 ◽  
Author(s):  
K. Skov ◽  
G. R. Williams
Keyword(s):  
Spectral Properties ◽  
Spectroscopic Properties ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Ferricytochrome C ◽  
Soret Region

One transition in the Soret region of ferricytochrome c has essentially the same pH, temperature, solvent, and conformational requirements as the 695 nm band. An important role for tyrosine in maintaining a structure with these spectral properties is indicated.

The effect of ligand binding and acid splitting on the optical rotatory dispersion of ferric horseradish peroxidase

1968 ◽  
Vol 46 (10) ◽  
pp. 1231-1235 ◽  
Author(s):  
William D. Ellis ◽  
H. Brian Dunford
Keyword(s):  
Horseradish Peroxidase ◽  
Ligand Binding ◽  
Protein Conformation ◽  
Spectral Region ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Helical Content ◽  
Protein Moiety ◽  
Soret Region

The optical rotatory dispersion of horseradish peroxidase and its cyanide, fluoride, and hydroxide complexes was studied in the spectral region 215–450 mμ, and that of the azide complex at 350–450 mμ. The effect that splitting the heme from the protein of peroxidase has on the optical rotatory dispersion in the 215–450 mμ region was also studied. Results of measurements of the reduced mean residue rotation at 233 mμ, lead to the conclusion that there are no significant changes in gross protein conformation upon the binding of ligands to peroxidase, but that the splitting of the heme causes a reduction of the helical content of the protein. Pure peroxidase was estimated to have 43% α-helical content, which was reduced to 33% when the heme was split from the protein. Results of studies in the Soret region indicate that the binding of various ligands does not cause an alteration of the geometry of the heme with respect to the protein moiety.

The Effect of Ligand Binding on the Optical Rotatory Dispersion of Lactoperoxidase

1971 ◽  
Vol 49 (6) ◽  
pp. 666-670 ◽  
Author(s):  
R. James Maguire ◽  
H. Brian Dunford
Keyword(s):  
Protein Conformation ◽  
Cotton Effect ◽  
Optical Rotatory Dispersion ◽  
Rotatory Dispersion ◽  
Optical Rotatory ◽  
Heme Group ◽  
Negative Cotton Effect ◽  
Fluoride Complexes ◽  
Protein Moiety ◽  
Soret Region

The optical rotatory dispersion of lactoperoxidase and its cyanide and fluoride complexes was studied over the spectral region 210–500 nm, and that of the azide complex from 350–450 nm. Results of the measurements of the reduced mean rotation at 233 nm lead to the conclusion that there are no significant changes in gross protein conformation upon the binding of these ligands to lactoperoxidase. Lactoperoxidase was estimated to have 17% α-helical character at pH 7.0. Results of studies in the Soret region indicate that lactoperoxidase, unlike horseradish peroxidase, hemoglobin, and myoglobin, exhibits a negative Cotton effect as do its cyanide, azide, and fluoride complexes. The binding of these ligands apparently causes an alteration of the geometry of the heme group with respect to the protein moiety.

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