title: Differential Large-Amplitude Breathing Motions in the Interface of FKBP12-Drug Complexes.
abstract: The tight complexes FKBP12 forms with immunosuppressive drugs, such as FK506 and rapamycin, are frequently used as models for developing approaches to structure-based drug design. Although the interfaces between FKBP12 and these ligands are well-defined structurally and are almost identical in the X-ray crystallographic structures of various complexes, our nuclear magnetic resonance studies have revealed the existence of substantial large-amplitude motions in the FKBP12-ligand interfaces that depend on the nature of the ligand. We have monitored these motions by measuring the rates of Tyr and Phe aromatic ring flips, and hydroxyl proton exchange for residues clustered within the FKBP12-ligand interface. The results show that the rates of hydroxyl proton exchange and ring flipping for Tyr26 are much slower in the FK506 complex than in the rapamycin complex, whereas the rates of ring flipping for Phe48 and Phe99 are significantly faster in the FK506 complex than in the rapamycin complex. The apparent rate differences observed for the interfacial aromatic residues in the two complexes confirm that these dynamic processes occur without ligand dissociation. We tentatively attribute the differential interface dynamics for these complexes to a single hydrogen bond between the ζ-hydrogen of Phe46 and the C32 carbonyl oxygen of rapamycin, which is not present in the KF506 complex. This newly identified Phe46 ζ-hydrogen bond in the rapamycin complex imposes motional restriction on the surrounding hydrophobic cluster and subsequently regulates the dynamics within the protein-ligand interface. Such information concerning large-amplitude dynamics at drug-target interfaces has the potential to provide novel clues for drug design.
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , 1-1 minami-ohsawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Chun-Jiun
authors.initials: CJ
authors.lastname: Yang
authors.affiliation: Structural Biology Research Center, Graduate School of Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Takeda
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , 1-1 minami-ohsawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Terauchi
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , 1-1 minami-ohsawa, Hachioji, Tokyo 192-0397, Japan.
authors.forename: JunGoo
authors.initials: J
authors.lastname: Jee
authors.affiliation: Department of Chemistry, Graduate School of Science and Engineering, Tokyo Metropolitan University , 1-1 minami-ohsawa, Hachioji, Tokyo 192-0397, Japan.|Structural Biology Research Center, Graduate School of Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Masatsune
authors.initials: M
authors.lastname: Kainosho
mesh_terms: D006801:Humans; D006860:Hydrogen Bonding; D007166:Immunosuppressive Agents / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D009038:Motion; D011485:Protein Binding; D011487:Protein Conformation; D020123:Sirolimus / Q000737:chemistry / Q000378:metabolism*; D016559:Tacrolimus / Q000737:chemistry / Q000378:metabolism*; D022061:Tacrolimus Binding Protein 1A / Q000737:chemistry / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D007166:Immunosuppressive Agents; D008024:Ligands; D022061:Tacrolimus Binding Protein 1A; D020123:Sirolimus; D016559:Tacrolimus