CONICET | Buscador de Institutos y Recursos Humanos

The structure and dynamics of thyroxine (T4), distal and proximal conformers of 3′,3,5-triiodo-L-thyronine(T3d and T3p), and 3,5-diiodo-L-thyronine (T2) upon interaction with DMPC membranes were analyzed bymeans of molecular dynamics simulations. The locations, the more stable orientations, and the structuralchanges adopted by the hormones in the lipid medium evidence that the progressive iodine substitution onthe ring lowers both the possibility of penetration and the transversal mobility in the membrane. However,the results obtained for T3d show that the number of iodine atoms in the molecule is not the only relevantfactor in the hormone behavior but also the orientation of the single iodine substitution. The electrostaticinteractions between the zwitterion group of the hormones with speciﬁc groups in the hydrophilic region ofthe membrane as well as the organization of the alkyl chains around the aromatic ring of the hormone wereevaluated in terms of several radial distribution functions.