Fig 4.

a) Radial distribution function (RDF) of polycation amine groups around O1P and O2P siRNA atoms for each molecular system reported in figure legend. Only charged amine groups are considered for the calculation. b) Average number of amine groups of each polycationic chain interacting with siRNA O1P and O2P atoms averaged over the last 20 ns of each Replica Exchange Molecular Dynamics trajectory at 300K. c) Radial distribution function (RDF) of polycation amine groups around electronegative atoms in siRNA grooves for each molecular system reported in figure legend. Only charged amine groups are considered for the calculation. The siRNA base edges that could participate in hydrogen bonds are N6 and N7 of adenine, O4 of uracil, O6 and N7 of guanine, and N4 of cytosine d) Average number of amine groups of each polycationic chain interacting with electronegative atoms in siRNA groves averaged over the last 20 ns of each Replica Exchange Molecular Dynamics trajectory at 300K.