... Preparation of Protein Structures Nine different PKA structures in complex with different ligands were obtained from the Protein Data Bank [12] (PDB Page 2. ... 1SZM 2.5 6 1YDR 2.2 7 1YDS 2.2 8 1YDT 2.3 9 Page 3. ... Letters in Drug Design & Discovery, 2009, Vol. 6, No. 5 329 ...