TY - JOUR
T1 - The stability of the cytochrome c scaffold as revealed by NMR spectroscopy
AU - Berners-Price, Susan
AU - Bertini, I.
AU - Gray, H.B.
AU - Spyroulias, G.A.
AU - Turano, P.
PY - 2004
Y1 - 2004
N2 - NMR spectroscopy was used to study the effect of guanidinium chloride on the unfolding of horse heart and yeast iso-1 cytochrome c under mild alkaline conditions. The structural changes on the horse heart protein were detected through NOESY (Nuclear Overhauser Effect SpectroscopY) experiments whereas N-15-H-1 heteronuclear NMR was used to monitor the behavior of the yeast protein. The latter represents the first characterization through N-15-H-1 heteronuclear NMR spectroscopy of the guanidinium chloride induced unfolding of mitochondrial cytochrome c. The presence of denaturants decreases the temperature at which the native Met80 axial ligand is displaced from the iron center under the present mild alkaline conditions. The process can be described in terms of protein fragments behaving as unfolding units of different stability. The comparison between the two proteins indicates that the loop + helix connecting the proximal and distal sites, as well as the long Met80-containing loop immediately after a short helix, are structural characteristics of mitochondrial cytochrome c that appear to be responsible for the Met80-iron(III) bond fragility. (C) 2003 Elsevier Inc. All rights reserved.
AB - NMR spectroscopy was used to study the effect of guanidinium chloride on the unfolding of horse heart and yeast iso-1 cytochrome c under mild alkaline conditions. The structural changes on the horse heart protein were detected through NOESY (Nuclear Overhauser Effect SpectroscopY) experiments whereas N-15-H-1 heteronuclear NMR was used to monitor the behavior of the yeast protein. The latter represents the first characterization through N-15-H-1 heteronuclear NMR spectroscopy of the guanidinium chloride induced unfolding of mitochondrial cytochrome c. The presence of denaturants decreases the temperature at which the native Met80 axial ligand is displaced from the iron center under the present mild alkaline conditions. The process can be described in terms of protein fragments behaving as unfolding units of different stability. The comparison between the two proteins indicates that the loop + helix connecting the proximal and distal sites, as well as the long Met80-containing loop immediately after a short helix, are structural characteristics of mitochondrial cytochrome c that appear to be responsible for the Met80-iron(III) bond fragility. (C) 2003 Elsevier Inc. All rights reserved.
U2 - 10.1016/j.jinorgbio.2003.12.010
DO - 10.1016/j.jinorgbio.2003.12.010
M3 - Article
VL - 98
SP - 814
EP - 823
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
SN - 0162-0134
ER -