In silico protein-protein interaction: C-phycocyanin has potential for block proliferation and adhesion proteins in cancer

The pathophysiology of cancer is related to diverse cellular and molecular dysfunctions. Unregulated proliferation can occur due to changes in pathways such as MAP kinase (ERK is the effector kinase). Metastasis linked to the worst prognosis is related to the unregulated function of adhesion proteins (like E-cadherins/ ECAD). The C-phycocyanin (C-PC) is a photosynthetic pigment with several biological activities, with the potential to inhibit ERK and ECAD in tumors. In this work, we evaluated the possible interaction of C-PC with ERK and ECAD to deepen the knowledge about the anti-tumor mechanisms of C-PC. Using the PRISM web server (algorithm based on structural matching) the interaction of the C-PC was verified (PDB ID: 1GH0) in its complete form (Full) or F chain with ERK (PDB ID: 2ZOQ) and ECAD (PDB ID: 2O72). Full C-PC interacted with ECAD with -5.77 of binding energy (BE). The F chain interacted with ERK (-20.99 BE) and ECAD (-41.71 BE). UCSF Chimera program revealed that the F chain binding to ECAD by 179 varied connections (polar, nonpolar, favorable and unfavorable), without establishing Hydrogen bonds. The chain F binding to ERK by 5 Hydrogen bonds and 264 varied connections. The chain F of C- seems to have greater biological action (in relation to the complete structure), because it was linked to the two targets. The greater BE demonstrates the greater stability of the protein complex, so the greatest action must occur on ECAD. However, the interaction in ERK by 5 hydrogen bonds should favor the role of C-PC on this protein. Thus, the interaction of C-PC with ERK and ECAD demonstrates its potential to reduce proliferation and metastasis, encouraging in vitro studies.