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

用碎片密度泛函理论（FDFT）分析了β肾上腺素能受体氨基酸残基与配体化合物之间的相互作用能，并对复合物的活性位点进行了归属。在β1、β2、β 3受体的相同位置上，配体与ASP之间存在强吸引作用。此外，在相同的位置，SER与激动剂的吸引相互作用，而几乎没有与拮抗剂。SER和激动剂之间的相互作用能被发现对应于EC 50值。因此，可以得出结论，ASP和SER的受体的主要结合和活性位点，分别。

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.