Molecular modeling of the complex between the xWNT8 protein and the CRD domain of the mFZD8 receptor

Structural and dynamic characterization of human Wnt2-Fzd7 complex using computational approaches

Wnt and Frizzled (Fzd) family members play crucial roles in the self-renewal of tumor-initiating cells. Until now, only a few studies have addressed the distinct mechanism of Wnt-Fzd interactions. In this study, we suggest a possible interaction mode of Wnt2 with the Fzd7 cysteine-rich domain (CRD)-both of which are up-regulated in some types of cancer. A combination of homology modeling, molecular docking and molecular dynamics (MD) simulations was carried out to study this ligand-receptor complex in great detail. The results demonstrated the unique dynamic behavior of Wnt2 upon binding to Fzd7. Interestingly, the β-strand content of the C-terminal binding site of Wnt2 was obviously reduced when bound to Fzd7 CRD. Moreover, the N-terminal and C-terminal binding sites of Wnt2 appeared to interact with the C-terminal and N-terminal binding sites of Fzd7, respectively. Calculation of the binding energies uncovered the pivotal role of electrostatic and hydrophobic interactions in the binding of Wnt2 to Fzd7 CRD. In conclusion, this study provides valuable insights into the mechanism of the Wnt2-Fzd7 CRD interaction for application in colorectal cancer prevention programs. Graphical abstract Flowchart representation of different steps used in this study.

Molecular modeling of modified peptides, potent inhibitors of the xWNT8 and hWNT8 proteins

Signaling pathways of Wnt-proteins and Fzd-receptors play important role in processes of growth and development of stem cells and in many types of cancers. The binding of the Wnt-proteins and Fzd-receptors is a complicated process, in which 19 Wnt-proteins and 10 Fzd-receptors are involved. Such a large number of combinations of Wnt-Fzd pairs leads to many different influences of Fzd-Wnt-complexes on the development and differentiation of stem cells. The molecular models of xWnt8, hWnt8, mFzd8, hFzd8-proteins and their complexes were constructed and studied in the present work. The amino acids of the binding sites of proteins which participate in these complexes formation and the protein-protein interactions were studied. The pharmacophoric model of the binding site on the xWnt8 and hWnt8-proteins was constructed. In this work we suggested the peptidomimetic ligands, which can be used for the inhibition of the xWnt8-mFzd8 and hWnt8-hFzd8 proteins formation. The de novo design method of Allegrow software was used for the predictions of most prospective functional groups of the peptidomimetic ligands. These ligands can be used as inhibitors of xWnt8-mFzd8 and hWnt8-hFzd8 complex formation and also can be used for drug design by other methods.