Structural dynamics in an electron-transfer complex.
The dynamic behaviour of the complex of horse cytochrome c with cytochrome c peroxidase, an electron-transfer complex, was studied in solution by a hydrogen exchange labelling method together with two-dimensional NMR analysis. Although cytochrome c hydrogens in the expected binding region exhibit slowed exchange, the measured slowing factors are very small, indicating that hydrogen-exchange occurs with little hindrance from within the binding interface. The complex in solution must therefore be highly mobile rather than rigidly defined, as implied by the crystalline complex. This result is in conflict with the concept that biological electron transfer occurs by way of predetermined covalent pathways.
Jeng
M F
MF
Johnson Research Foundation, Department of Biochemistry & Biophysics, University of Pennsylvania School of Medicine, Philadelphia 19104-6059, USA.
Englander
S W
SW
Pardue
K
K
Rogalskyj
J S
JS
McLendon
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D003574:Cytochrome c Group / Q000737:chemistry* / Q000235:genetics; D003578:Cytochrome-c Peroxidase / Q000737:chemistry*; D004579:Electron Transport; D006736:Horses; D006859:Hydrogen / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D017510:Protein Folding
D003574:Cytochrome c Group; D006859:Hydrogen; D003578:Cytochrome-c Peroxidase