Tiagabine could bind in Sudlow site II of HSA and BSA.

Metandienone (MET) is an exogenous anabolic androgenic steroid. The interaction between MET and human serum albumin (HSA) was investigated by molecular modeling and different optical techniques. There was no possibility of energy transfer, and the fluorescence quenching of HSA induced by MET was mainly due to the complex formation. The differences of binding ability between MET and compounds 1-5 were significantly caused by space steric hindrance. The single crystallographic data of two steroids (compounds 4 and 5) were obtained in the methanol at the first time. In addition, the binding ability was slightly affected by -OH, -CH , and -COCH . The results of displacement experiment demonstrated that the MET binding site was mainly located in site 1 of HSA. H-bonding and van der Waals forces were significant in the MET-HSA binding. MET played an insignificant role on the local conformation change in HSA.