In this work we have studied the properties of mimosine and its influence on polypeptides containing it using atomistic molecular dynamics (MD) simulations. MD has become a standard tool for the characterization of structural propensities of peptides and disordered proteins in aqueous solution. However, for non-protein amino acids like mimosine, parameters for running simula- tions are not widely available. To that end we have parametrized the mimosine residue for two widely used Amber force fields, ff99SB and ff03. We have then run simulations of two peptides of different lengths relevant as metal chelators, and studied the effects of mimosine residues.