To test the "shroud" model hypothesis with respect to the altered local environment along the protein backbone, molecular dynamics (MD) simulations were performed for three systems: Gal3C, Gal3C-PEG 600 Da and Gal3C-PEG 5 kDa. The root mean squared displacement (RMSD) of protein residues was computed to assess the equilibrium of the simulated proteins, which shows that the structure reaches a stable state for the last 30 ns out of the 100 ns trajectory (Figure ). As a result, all structural analyses were conducted using the final 30 ns of the trajectory. To visualize the effects of the short and long PEG chain, flexible and long enough to cover a substantial portion of the protein surface, particularly the back and sides, giving the appearance of a "backpack". Consequently, Gal3C-PEG 5 kDa has more "shrouding"