Huanget al. also suggested that the presence of ��hairpin segments and extended hydrophobic surfaces facilitated the aggregation of hIAPP. In addition, several molecular dynamics simulations also detected that ��-hairpin structure played an important role in the assembly of a range of peptides associated with amyloid formation such as A�� and amylin. In this study, we find that the A117V PMSF mutated PrP106-126 acquires more ��-hairpin structures than the WT PrP106-126 and its H111S mutant, which may provide a plausible molecular basis for why the A117V mutant exhibits stronger propensity of aggregation. To better visually assess the differences in the contact maps upon mutations, we also produced substracted contact maps between A117V and WT and between H111S and WT. As shown in Fig8, the three species show significant differences in the residue-residue contact propensity. Compared to WT, the inclusion of hydrophobic residue Val117 makes the short ranged Tazobactam contacts among the residues decrease, especially the interactions between the114thand the 117th residues. In WT, the contacts between Gly114 and Ala117represent the strongest interaction among residues with probability of 40%, while the probability of contacts between two residues in the A117V mutant is 26%. In contrast with the impaired short-ranged interactions, the long-ranged interactions are enhanced by the inclusion of the A117V mutation, which indicate that the A117V mutation may increase the conformational freedom of PrP106126. The enhanced conformational freedom may make the peptide be more inclined to acquire ��-sheet structures. Compared to WT, H111S significantly enhances short-range interactions among N-terminal residues of the peptide. The most notable effect is a significant increased contact probability between Asn108 and Ser111. Meanwhile, Met109-Met112 and Asn108-Met112 pair-wise contact probabilities are also relatively higher than that in WT. Compared to histidine, the more hydrophilic serine displays much weaker interactions with the hydrophobic C-terminal residues.