Solution conformations of KNI-272, a tripeptide HIV protease inhibitor designed on the basis of substrate transition state: determined by NMR spectroscopy and simulated annealing calculations.
KNI-272, a highly selective and potent HIV protease inhibitor containing allophenylnorstatine [(2S,3S)-3-amino-2-hydroxy-4-phenylbutyric acid], named Apns, has been studied in dimethylsulfoxide-d6 by NMR spectroscopy and simulated annealing calculations. 1H and 13C spectra showed the presence of two conformers characterized by the configuration of the imide bond between the Apns and Thz residues, i.e., trans and cis forms, respectively. Rotating frame Overhauser effect spectra revealed that the trans conformer is dominant. The solution structure calculated from the distance information resulting from nuclear Overhauser effects experiments is similar overall to those observed in the solid states, either as a single crystal or as complex with the protease. The results from both molecular dynamics simulations and experimental 13C longitudinal relaxation times indicate that the backbone of KNI-272 has a fairly rigid conformation.
Institute for Protein Research, Osaka University, Japan.
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Ohno
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Kiso
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Kobayashi
D018360:Crystallography, X-Ray; D015195:Drug Design; D017320:HIV Protease Inhibitors / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry*; D011487:Protein Conformation
D017320:HIV Protease Inhibitors; D009842:Oligopeptides; C077822:kynostatin 272