We perform a theoretical study of the temperature dependent electronic specific heat at constant volume CV(T) for a fibrous α 3 -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 α 3 -helical polypeptide, namely those with (5Qα 3 variant, mutation Ala5Gln) and without (7Qα 3 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.