Based on the Peyrard–Bishop–Dauxois (i.e. the extendedPeyrard–Bishop) model of DNA dynamics, the transversal hydrogeninteraction is modelled by Morse potential and the impact of the Morseparameters on the DNA dynamics is investigated. In particular, we showhow modulation of the signal, moving through the DNA chain, depends onthose parameters. It is also shown that the DNA dynamics represents theinterplay between dispersion and nonlinearity. Finally, we discuss thevalues of coupling constants k and K.