Semiconductivity in proteins

The Hartree-Fock gap for the main chain is 12.4 eV (which decreases to 11.6 eV due to the long-range correlation), while for the hydrogen-bonded chain its value is (due to the smaller bandwidths) still larger ( 14.8 eV). Owing to this large gap intrinsic semiconduction in proteins seems to be negligible and the role of various impurities becomes important.99... 

The gap varies between about 16 and 11 eV. These values are far too large to allow intrinsic semiconductivity in proteins (however, according to the discussion in Section 2.3.1, the use of a better basis set and the... 

The experimental evidence is increasing that the electrical properties of proteins play an essential role in their biological functions (9). Since the early suggestions of Szent-Gybrgyi (10) and of Laki (11) concerning the possibility of semiconduction in proteins and its relation to cancer (12) a number of theoretical investigations has been devoted to the determination of the energy band structures (13) and of the possible pathways for electron delocalization (14) in these systems. 

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