Collagen-based biomaterials are expected to become a useful matrix substance for various biomedical applications in the future. By taking advantage of the crystallographic data of the triple-helical peptide T3-785, a collagen-like peptide whose homotrimeric structure presents large conformational similarity to the human type III collagen, we present a quantum biochemistry study to unveil its detailed binding energy features, taking into account the inter-chain interaction energies of 90 amino acid residues distributed into three interlaced monomers. Our theoretical model is based on the density functional theory (DFT) formalism within the molecular fragmentation with conjugate caps (MFCC) approach. We predict the individual relevance (energetically) of the amino acid triplets Pro–Hyp–Gly, Ile–Thr–Gly, Ala–Arg–Gly and Leu–Gly–Ala, as well as the influence of the N-terminal, central and C-terminal regions, looking for the integrity of the collagen's triple helix. We found that the amino acid residues comprising the peptide T3-785 have an interaction energy that depends not only on the chemical nature of the side chain, but also the surrounding solvent molecules and inter-chain intermolecular interactions. The energy profile of this collagen-model molecule depicts a character essentially attractive to its conformational stability, encouraging research focusing on the development and synthesis of artificial collagen with high stability for bioengineering applications.