Theoretical Analyses on Interactions between GPCR and Ligand Compounds with Fragment Method

用片段密度泛函理论分析了β肾上腺素能受体中氨基酸残基与配体化合物的相互作用能，并对其活性中心进行了归属。在β-1、β-2、β-3受体的相同位置观察到配体与天冬氨酸的强相互作用。此外，在相同的位置，SER与激动剂有很好的相互作用，但与拮抗剂几乎没有作用。SER与激动剂之间的相互作用能与EC50值相对应。因此，受体中的天冬氨酸和SER分别是主要的结合部位和活性部位。

The interaction energies between the amino acid residues inβadrenergic receptors and ligand compounds were analyzed with Fragment Density Functional Theory (FDFT), to assign active sites of these complexes. The strongly attractive interactions between the ligands and ASP at the same positions of the respectiveβ1,β2,β3receptors, were observed. Furthermore, SER at the same positions attractively interacted with the agonists, but hardly with the antagonists. The interaction energies between the SER and the agonists were found to be corresponding to the EC50 values. Therefore, it was concluded that the ASP and SER in the receptors were the major binding and active sites, respectively.