Temperature-dependent spin-state equilibrium in an azide-ferric heme octapeptide complex. A model system for the spin equilibriums of ferric heme proteins

1979 ◽  
Vol 101 (19) ◽  
pp. 5807-5810 ◽  
Author(s):  
Ya-Ping Huang ◽  
Richard J. Kassner
Keyword(s):  
Spin State ◽  
Heme Proteins ◽  
Model System ◽  
Temperature Dependent ◽  
State Equilibrium ◽  
Ferric Heme

scholarly journals Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies

2020 ◽  
Vol 117 (36) ◽  
pp. 21914-21920 ◽  
Author(s):  
Camila Bacellar ◽  
Dominik Kinschel ◽  
Giulia F. Mancini ◽  
Rebecca A. Ingle ◽  
Jérémy Rouxel ◽  
...  
Keyword(s):  
Heme Proteins ◽  
Thermal Relaxation ◽  
Major Protein ◽  
Edge Structure ◽  
X Ray ◽  
Electron Transfer Protein ◽  
Cyt C ◽  
Ferric Heme ◽  
Function Relationship ◽  
X Ray Absorption

The structure–function relationship is at the heart of biology, and major protein deformations are correlated to specific functions. For ferrous heme proteins, doming is associated with the respiratory function in hemoglobin and myoglobins. Cytochromec(Cyt c) has evolved to become an important electron-transfer protein in humans. In its ferrous form, it undergoes ligand release and doming upon photoexcitation, but its ferric form does not release the distal ligand, while the return to the ground state has been attributed to thermal relaxation. Here, by combining femtosecond Fe Kαand KβX-ray emission spectroscopy (XES) with Fe K-edge X-ray absorption near-edge structure (XANES), we demonstrate that the photocycle of ferric Cyt c is entirely due to a cascade among excited spin states of the iron ion, causing the ferric heme to undergo doming, which we identify. We also argue that this pattern is common to a wide diversity of ferric heme proteins, raising the question of the biological relevance of doming in such proteins.

Ultrafast Observation of a Solvent Dependent Spin State Equilibrium in CpCo(CO)

2012 ◽  
Vol 134 (6) ◽  
pp. 3120-3126 ◽  
Author(s):  
Justin P. Lomont ◽  
Son C. Nguyen ◽  
Jacob P. Schlegel ◽  
Matthew C. Zoerb ◽  
Adam D. Hill ◽  
...  
Keyword(s):  
Spin State ◽  
State Equilibrium

Iron(II) complexes of 2,4-Bis(2-pyridyl)thiazole

1968 ◽  
Vol 21 (12) ◽  
pp. 2881 ◽  
Author(s):  
HA Goodwin ◽  
RN Sylva
Keyword(s):  
Temperature Dependence ◽  
Spectral Data ◽  
Spin State ◽  
State Equilibrium ◽  
Infrared Spectral

Mono and bis iron(11) complexes of 2,4-bis(2-pyridyl)thiazole have been described. Conductivity and visible and infrared spectral data suggest that the mono complexes are five-coordinate. The magnetism of the bis complexes, in contrast to that of the mono complexes, shows unusual temperature dependence. This has been ascribed to the presence, in the bis complexes, of a spin-state equilibrium. Bis[2,4-bis(2-pyridyl)thiazole]cobalt(11) perchlorate has been shown to be a simple paramagnetic compound.

Heteroactivator effects on the coupling and spin state equilibrium of CYP2C9

2006 ◽  
Vol 449 (1-2) ◽  
pp. 115-129 ◽  
Author(s):  
Charles W. Locuson ◽  
Peter M. Gannett ◽  
Timothy S. Tracy
Keyword(s):  
Spin State ◽  
State Equilibrium
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