Discovery of Novel Human Phenylethanolamine N-methyltransferase (hPNMT) Inhibitors Using 3D Pharmacophore-Based in silico, Biophysical Screening and Enzymatic Activity Assays

• Published in: Molecules and cells 2010, 29(6), , pp.595-602
• Main Authors: Kang, D.I., Konkuk University, Seoul, Republic of Korea, Lee, J.Y., Konkuk University, Seoul, Republic of Korea, Kim, W.H., Konkuk University, Seoul, Republic of Korea, Jeong, K.W., Konkuk University, Seoul, Republic of Korea, Shin, S.Y., Konkuk University, Seoul, Republic of Korea, Yang, J.Y., Konkuk University, Seoul, Republic of Korea, Park, E.J., Konkuk University, Seoul, Republic of Korea, Chae, Y.K., Sejong University, Seoul, Republic of Korea, Kim, Y.M., Konkuk University, Seoul, Republic of Korea
• Format: Article
• Language: English
• Subjects: ADRENALINE; Biochemistry; Biomedical and Life Sciences; Biomedicine; Biophysical Phenomena; Biotechnology; Cell Biology; Chromatography, High Pressure Liquid; Combinatorial Chemistry Techniques; Drug Discovery - instrumentation; Drug Discovery - methods; Drug Evaluation, Preclinical - instrumentation; Drug Evaluation, Preclinical - methods; Enzyme Assays; Enzyme Inhibitors - chemistry; Enzyme Inhibitors - isolation & purification; Enzyme Inhibitors - metabolism; Enzyme Inhibitors - pharmacology; EPINEFRINA; EPINEPHRINE; Humans; Hydrogen Bonding; in silico screening; Life Sciences; Models, Chemical; Molecular Conformation; pharmacophore; Phenylethanolamine N-Methyltransferase - antagonists & inhibitors; Phenylethanolamine N-Methyltransferase - metabolism; PNMT; Protein Binding; 생물학
• ISSN: 1016-8478; 0219-1032
• DOI: 10.1007/s10059-010-0074-3

With the aid of receptor-oriented pharmacophore-based in silico screening, we established three pharmacophore maps explaining the binding model of hPNMT and a known inhibitor, SKnF 29661 (Martin et al., 2001). The compound library was searched using these maps. Nineteen selected candidate inhibitors of hPNMT were screened using STD-NMR and fluorescence experiments. An enzymatic activity assay based on HPLC was additionally performed. Consequently, three potential hPNMT inhibitors were identified, specifically, 4-oxo-1,4-dihydroquinoline-3,7-dicarboxylic acid, 4-(benzo[d][1,3]dioxol-5-ylamino)-4-oxobutanoic acid, and 1,4-diaminonaphthalene-2,6-disulfonic acid. These novel inhibitors were retrieved using Map Ⅱ comprising one hydrogen bond acceptor, one hydrogen bond donor, one lipophilic feature, and shape constraints, including a hydrogen bond between Lys57 of hPNMT and a hydrogen bond donor of the inhibitor, and stacked hydrophobic interactions between the side-chain of Phe182 and an aromatic region of the inhibitor. Water-mediated interactions between Asn267 and Asn39 of hPNMT and the amide or amine group of three potent inhibitors were additional important features for hPNMT activity. The binding model presented here may be applied to identify inhibitors with higher potency. Moreover, our novel compounds are valuable candidates for further lead optimization of PNMT inhibitors.