Then, we assessed the effect of mimosine in the conformational preferences of short peptides, relative to its most similar amino acids, Phe and Tyr. In contrast to both of them, we observed the off-register stacking of the Mms rings, due to the higher atomic charges on its ring and b carbon. The MD simulations showed that polypeptides containing various Mms amino acids in their sequence go under considerably less conformational changes than their analogues. This is caused by the highly favored Mms ring stacking. Most conformations that these polypeptides adopted throughout the simulations had their rings stacked, severely limiting the diversity of observed conformations. In the ff99SB force field the ring stacking of Mms peptides separated by the Gly-Pro-Gly chain the ring is favoured over others, dictating the behavior of the polypeptides containing this sequence. In the ff03 force field multiple ring stacking arrangements are prevalent, resulting in a greater variability of conformations.