title: Nuclear magnetic resonance and molecular modeling study on mycophenolic acid: implications for binding to inosine monophosphate dehydrogenase.
abstract: The conformation of the sodium salt of mycophenolic acid (MPA), a potent inhibitor of inosine monophosphate dehydrogenase (IMPD), derived from 1D DIFNOE and 2D ROESY experiments in water and molecular dynamics (MD) is described. The hexenoic acid side chain conformation consistent with the NMR data was similar to that seen in the X-ray structure of MPA. The solution conformation was applied in a molecular modeling study in order to explore the potential features of enzyme binding. Our results, based on striking similarities in molecular volume and electrostatic isopotential between MPA and cofactor NAD+, lead to the suggestion that MPA is capable of binding to the nicotinamide site of IMPD and mimicking the NAD+ inverse regulation of the enzyme. In addition, our proposed model is in good agreement with the observed high affinity of the dinucleotide analogues thiazole- and selenazole-4-carboxamide adenine dinucleotide to IMPD.
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, State University of New York at Buffalo, 14260, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Makara
authors.forename: G M
authors.initials: GM
authors.lastname: Keserû
authors.forename: M
authors.initials: M
authors.lastname: Kajtár-Peredy
authors.forename: W K
authors.initials: WK
authors.lastname: Anderson
mesh_terms: D004791:Enzyme Inhibitors / Q000737:chemistry*; D007168:IMP Dehydrogenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D009173:Mycophenolic Acid / Q000737:chemistry* / Q000378:metabolism; D009243:NAD / Q000737:chemistry
chemical_list: D004791:Enzyme Inhibitors; D009243:NAD; D007168:IMP Dehydrogenase; D009173:Mycophenolic Acid