Tuning energy transport in helical protein nanotubes through side-chain modifications.

Fibrous proteins are widely used as materials due to their biocompatibility, flexibility, and mechanical properties. With advancements in bioelectronics and flexible materials, there is increasing demand for biocompatible materials with tunable thermal conductivity. Understanding the mechanisms of thermal transport in proteins can facilitate the design of biomaterials with tailored thermal properties. In this study, we use non-equilibrium molecular dynamics (NEMD) to investigate how side-chain mass affects thermal transport in α-helix proteins. We analyze four representative residues - glycine (G), alanine (A), leucine (L), and phenylalanine (F) - and demonstrate that variations in side-chain mass significantly influence thermal conductivity. Results show that heavier side chains hinder heat transport, while lighter side chains enhance it. Phonon analysis reveals that side-chain mass primarily affects the properties of low-frequency acoustic and semi-optical phonons, which are critical for energy transfer. These findings provide insights into the design of protein-based biomaterials with customized thermal properties, offering potential applications in bioelectronics, medical devices, and sustainable materials. STATEMENT OF SIGNIFICANCE: This research explores how side chains in α-helix proteins influence their thermal conductivity through the application of molecular dynamics simulations. By analyzing four types of amino acids with differing side-chain masses, the study demonstrates that lighter side chains enhance heat transport, whereas heavier ones diminish it. This work establishes a direct correlation between protein structural features and their thermal properties, providing the groundwork that could enable the engineering of biomaterials with tailored heat conduction capabilities. The findings have implications for applications in bioelectronics, medical devices, and sustainable materials, where precise thermal management is essential, rendering this research highly relevant to scientists and engineers focused on advancing biocompatible materials with specific thermal characteristics.