Increasing the Efficiency Efficiency of Ligands for the FK506-Binding Protein 51 by Conformational Control: Complex of FKBP51 with compound 1-[(9S,13R,13aR)-1,3-dimethoxy-8-oxo-5,8,9,10,11,12,13,13a-octahydro-6H-9,13-epiminoazocino[2,1-a]isoquinolin-14-yl]-2-(3,4,5-trimethoxyphenyl)ethane-1,2-dione
