Biocompatible branched polymers can be used in many biomedical applications, including drug and gene delivery. In previous articles, we applied a computational approach to study complexes of positively charged lysine branched polymers and their complexes with some negatively charged regulatory oligopeptides. The goal of this article is to test the possibility of complex formation between peptide dendrimer and therapeutic oligopeptide molecules. A system consisting of one dendrimer, 16 oligopeptide molecules and counterions in water was studied by the molecular dynamics method. For this purpose, the Gromacs molecular modeling software package and the Amber force field were used. First of all, the process of complexation was studied and it was shown that negatively charged oligopeptide molecules are attracted by the dendrimer and quickly form a stable complex with it. After reaching a plateau of all characteristics of the complex, its average equilibrium dimensions, shape anisotropy, and internal structure were calculated. They turned out to be similar to the characteristics of the complexes formed by other branched lysine molecules with similar molecular weights and charges.