Electronic specific heat of an α3-helical polypeptide and its biochemical variants

We perform a theoretical study of the temperature dependent electronic specific heat at constant volume C V ( T ) for a fibrous α3-helical polypeptide, which has the amino acid sequence (Leu-Glu-Thr-Leu-Ala-Lys-Ala)3, considering only its primary structure. We focus also on two different variants of the α3-helical polypeptide, namely those with (5Qα3 variant, mutation Ala5Gln) and without (7Qα3 variant, mutation Ala7Gln) fibrous assemblies. The energy spectra are calculated using a two-dimensional Schrödinger equation within a tight-binding approximation in which the isolated amino acid vertical ionization energy and the hopping terms are found using density functional theory computations.