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On the energetics of conformational changes and pH dependent redox behaviour of electron transfer proteins
Author(s) -
Rogers Neil K.,
Moore Geoffrey R.
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)80587-8
Subject(s) - energetics , redox , electron transfer , chemistry , conformational change , biophysics , electron transport chain , chemical physics , electron , crystallography , biochemistry , thermodynamics , photochemistry , inorganic chemistry , biology , physics , quantum mechanics
Calculations of the electrostatic interaction energies for four metalloproteins that carry out electron transfer are reported. Each protein has a pH dependent redox potential from which the measured electrostatic interaction energy is obtained. The calculations were made using the X‐ray structure coordinates and a semimacroscopic model of the interactions. For cytochrome c ‐551 and HIPIP the calculated and observed interaction energies were found to be approximately the same, in agreement with the fact that significant conformational changes do not accompany the ionisations. For cytochrome c 2 and azurin, however, major differences were found between the calculated and observed values. These are accounted for primarily by the occurrence of significant conformational changes accompanying the ionisations. The reorganisation energies for these conformational changes are ∼7.0 and ∼11.1 kJ·mol −1 , respectively.