Jahn-Teller effect in biomolecules

The role played by the Jahn-Teller effect for a correct interpretation of the spectroscopic and structural data of some biological systems is stressed and a short review of the investigations so far performed is presented. Afterwards, on the basis of the angular overlap model, several expressions are given for the coupling constants of the transition metal ions, which mainly occur in biomolecules (Fe, Co, Cu, Mo) in order to have an approximate evaluation of the Jahn-Teller effect magnitude. The above expressions are then applied to obtain the vibronic coupling constants of the deoxygenated hemoglobin and myoglobin. The results obtained are compared with the predictions previously made by the author on these systems. (Auth.)