Abstract
The human S100 calcium-binding protein A11 (S100A11) is a member of S100 protein family. Once S100A11 proteins bind to calcium ions at EF-hand motifs, S100A11 will change its conformation promoting interaction with target proteins. The receptor for advanced glycation end products (RAGE) consists of three extracellular domains, including V domain, C1 domain and C2 domain. In this case, V domain is the target for mS100A11 binding. RAGE binds to the ligands result in cell proliferation, cell growth and several signal transduction cascades. We used NMR and fluorescence spectroscopy to demonstrate the interactions between S100A11 and V domain. The Tranilast molecule is a drug used for treating allergic disorders. We found out that V domain and Tranilast would interact with S100A11 by using 1H-15N HSQC NMR titrations. According to the results, we obtained two binary complex models from the HADDOCK program, S100A11-RAGE V domain and S100A11-Tranilast, respectively. We superimposed these two models with the same orientation of S100A11 homodimer and demonstrated that Tranilast molecule would block the binding site between S100A11 and V domain. We further utilized the WST-1 assay to indicate that Tranilast indeed can inhibit the cell proliferation which is induced by the S100A11-V domain interaction. These results will be potentially useful in the development of derivative or new anti-cancer drugs for RAGE-dependent diseases.