No / This chapter gives an introduction to protein simulation methodology aimed at experimentalists and graduate students new to in silico investigations. More emphasis is placed on the knowledge needed to select appropriate simulation protocols, leaving theoretical and mathematical depth for other texts to take care of. The chapter explains some of the more practical considerations of performing simulations of proteins, in particular, the additional considerations required when studying protein folding where nonnative environments are modeled. Forced unfolding simulations are highly relevant and invaluable in characterizing proteins naturally exposed to mechanical stress as a component of their biological function. The chapter illustrates this utility by discussing research that has been done primarily on the giant muscle protein titin. Using Molecular dynamics (MD) simulations to investigate protein folding faces two main challenges. The most obvious relates to the timescale of protein folding and the computational expense required for adequate sampling. / NIH