ELECTRON-TRANSFER IN AZURIN AND THE ROLE OF AROMATIC SIDE GROUPS OF THE PROTEIN

Intramolecular electron-transfer reaction in azurin, studied experimentally by Farver and Pecht, is examined with respect to the electronic coupling between the redox centers. The electronic factor is calculated by using a tight-binding method for two possible pathways, one with aromatic groups and one without such groups. Although the former pathway has a larger electronic factor, closer inspection of the results shows that this is not due to electron-transfer-promoting properties of the aromatic groups but can be explained as differences in the peptide backbone interactions.