Spectroscopic characterization of heme A reconstituted myoglobin.
The focus of this study was to examine the functional role of the unusual peripheral substitution of heme A. The effects of heme A stereochemistry on the reconstitution of the porphyrin have been examined in the heme A-apo-myoglobin complex using optical absorption and resonance Raman and electron paramagnetic resonance spectroscopies. The addition of one equivalent of heme A to apo-Mb produces a complex which displays spectroscopic signals consistent with a distribution of high- and low-spin heme chromophores. These results indicate that the incorporation of heme A into apo-Mb significantly perturbs the protein refolding.
Larsen
R W
RW
Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena 91125.
Nunez
D J
DJ
MacLeod
J
J
Shiemke
A K
AK
Musser
S M
SM
Nguyen
H H
HH
Ondrias
M R
MR
Chan
S I
SI
D000818:Animals; D002417:Cattle; D004121:Dimethyl Sulfoxide; D004578:Electron Spin Resonance Spectroscopy; D005290:Ferric Compounds / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry; D006418:Heme / Q000031:analogs & derivatives* / Q000737:chemistry; D009211:Myoglobin / Q000737:chemistry*; D011487:Protein Conformation; D013057:Spectrum Analysis; D013059:Spectrum Analysis, Raman; D013329:Structure-Activity Relationship
D005290:Ferric Compounds; D005296:Ferrous Compounds; D009211:Myoglobin; C027728:heme a; D006418:Heme; D004121:Dimethyl Sulfoxide