Computationally Exploring FKBP65’s Interaction with Collagen

FKBP65, a 4-domain FK506-binding protein, acts as a peptidyl-prolyl cis/trans isomerase (PPIase). It catalyzes the cis/trans isomerization of proline in collagen and assists in collagen maturation. Overexpressed collagen creates a microenvironment favorable to tumors, promotes tumor growth, facilitates metastasis, and induces heavy fibrosis. Therefore, finding a chemical compound that can decrease FKBP65’s interaction with collagen might improve cancer outcomes. Despite this target's importance, relatively little is known about each putative PPIase domain. We used ChimeraX to evaluate each domain and found that domains 1, 2, and 3 have probable PPIase activity, while domain 4 likely did not. We then identified portions of the collagen sequence likely recognized by each domain. Next, we identified target regions on each domain for inhibition. Finally, we used small molecule docking to identify potential inhibitors. We discuss the prospects for these inhibitors as potential cancer drugs.