The solvent is an integral component in all cellular processes and solvent composition is actively regulated in the living cell. Changes in solvent environment constitute a chemical signal that is transduced into a mechanical response: a chemically induced change of mechanical properties of a protein system. In this study, steered molecular dynamics simulations are used to stretch mechanical proteins set in non-aqueous solvent environment to reveal details and mechanism of protein - solvent interactions. We explore the atomic level mechanism and measure the effect of solvent substitution on the mechanical properties of proteins. We investigate the distance to the transition state during force induced unfolding as a function of solvent molecule size and the atomistic detail and timescale of participation of solvent molecules in the transition state structure. Resulting constant velocity and constant force extension profiles showed increased stability and resistance to unfolding force by proteins solvated in deuterium oxide vs. proteins solvated in water. Solvent molecules were found present the transition state structure and involved in forming a stabilizing bridge between the force-bearing sheer topology elements. Features of the simulations were also matched with previously reported experimental results.