| Autor: |
Lange, Reinhard, Gaston Hui Bon Hoa, Debey, Pascale, Gunsalus, Irwin C. |
| Předmět: |
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| Zdroj: |
European Journal of Biochemistry; 8/1/77, Vol. 77 Issue 3, p479-485, 7p |
| Abstrakt: |
The kinetic rate constants of formation and dissociation of the cytochrome-P-450 · camphor complex (Fe3+ · RH) have been obtained by low-temperature (+ 5 °C to - 20 °C) stopped-flow experiments. Similarly the high-spin/low-spin equilibrium of this complex has been studied as a function of temperature and protonic activity. Both the camphor-binding mechanism and the high-spin/low-spin thermodynamic parameters of Fe3+ · RH depend on the protonic activity of the medium in the physiological pH range. The binding rate constants are shown to depend on the ionization of a residue of the protein, probably a histidine. Linear enthalpy-entropy compensation is observed for the camphor binding as well as for the spin-state transition. A camphor-binding-induced change of the electrostatic potential is discussed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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