title: Rigid backbone moiety of KNI-272, a highly selective HIV protease inhibitor: methanol, acetone and dimethylsulfoxide solvated forms of 3-[3-benzyl-2-hydroxy-9-(isoquinolin-5-yloxy)-6-methylsulfanylmethyl-5,8-dioxo-4,7-diazanonanoyl]-N-tert-butyl-1,3-thiazolidine-4-carboxamide.
abstract: When crystals of kynostatin (KNI)-272, a highly selective HIV protease inhibitor containing allophenylnorstatine [(2S,3S)-3-amino-2-hydroxy-4-phenylbutyric acid], were grown in three different solvent systems (methanol, acetone and dimethylsulfoxide solutions), the local conformations around the hydroxymethylcarbonyl (HMC) moiety, which mimics the structure of the transition state, were similar in all three forms. The peptide backbones were slightly bent, but their structures differed from typical sheets, turns or helixes. Although the isoquinoline ring at the N-terminal showed conformational variations, a remarkable similarity was observed in the C-terminal region, including the HMC moiety. Moreover, the conformational characteristics of the uncomplexed forms resembled those of the inhibitor within the KNI-272-HIV protease complex. This suggests that the structure of the C-terminal region of KNI-272 is rigid or very stable.
authors.affiliation: Osaka University of Pharmaceutical Sciences, Nasahara, Takatsuki, 569-104, Japan. doit@gly.oups.ac.jp
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Doi
authors.forename: Tooru
authors.initials: T
authors.lastname: Kimura
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Ishida
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kiso
mesh_terms: D000096:Acetone; D018360:Crystallography, X-Ray; D004121:Dimethyl Sulfoxide; D017320:HIV Protease Inhibitors / Q000737:chemistry*; D000432:Methanol; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D009842:Oligopeptides / Q000737:chemistry*; D012997:Solvents
chemical_list: D017320:HIV Protease Inhibitors; D009842:Oligopeptides; D012997:Solvents; D000096:Acetone; C077822:kynostatin 272; D000432:Methanol; D004121:Dimethyl Sulfoxide