Molecular docking
Molecular docking study was carried out using the SYBYL-X 2.0 version to explore the binding mode of tacrolimus with MRGPRX2. The Xray crystal structure of MRGPRX2 (PDB code: 7S8N) was downloaded from PDB Bank. Water molecules were removed, and hydrogen was added. Tripos force field and Pullman charge were applied to minimize the molecular energy. Each drug molecule was depicted by the Sybyl/Sketch module (Tripos Inc.), optimized by Powell’s method with the Tripos force field with convergence criterion at 0.005 kcal/(Å mol), and assigned using the Gasteiger–Hückel method.