title: Inhibitory potential of flavonoids on PtdIns(3,4,5)P3 binding with the phosphoinositide-dependent kinase 1 pleckstrin homology domain.
abstract: Many membrane-associated proteins are involved in various signaling pathways, including the phosphoinositide 3-kinase (PI3K) pathway, which has key roles in diverse cellular processes. Disruption of the activities of these proteins is involved in the development of disease in humans, making these proteins promising targets for drug development. In most cases, the catalytic domain is targeted; however, it is also possible to target membrane associations in order to regulate protein activity. In this study, we established a novel method to study protein-lipid interactions and screened for flavonoid-derived antagonists of PtdIns(3,4,5)P3binding with the phosphoinositide-dependent kinase 1 (PDK1) pleckstrin homology (PH) domain. Using an enhanced green fluorescent protein (eGFP)-tagged PDK1 PH domain and 50% sucrose-loaded liposomes, the protein-lipid interaction could be efficiently evaluated using liposome pull-down assays coupled with fluorescence spectrophotometry, and a total of 32 flavonoids were screened as antagonists for PtdIns(3,4,5)P3binding with the PDK1 PH domain. From this analysis, we found that two adjunct hydroxyl groups in the C ring were responsible for the inhibitory effects of the flavonoids. Because the flavonoids shared structural similarities, the results were then subjected to quantitative structure-activity relationship (QSAR) analysis. The results were then further confirmed by in silico docking experiments. Taken together, our strategy presented herein to screen antagonists targeting lipid-protein interactions could be an alternative method for identification and characterization of drug candidates.
authors.affiliation: Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
authors.forename: Yelin
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Department Forest Resources, Gyeongnam National University of Science and Technology, 33 Dongjin-ro, Jinju-si, Gyeongsangman-do 660-758, Republic of Korea.
authors.forename: Bong-Gyu
authors.initials: BG
authors.lastname: Kim
authors.affiliation: Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
authors.forename: Sunghoon
authors.initials: S
authors.lastname: Kim
authors.affiliation: Division of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea.
authors.forename: Youngshim
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Department of Environmental Health Science, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea. Electronic address: yyoon21@gmail.com.
authors.forename: Youngdae
authors.initials: Y
authors.lastname: Yoon
mesh_terms: D064413:3-Phosphoinositide-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001665:Binding Sites; D047309:Flavones / Q000737:chemistry / Q000378:metabolism; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism*; D044948:Flavonols; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D062105:Molecular Docking Simulation; D018129:Phosphatidylinositol Phosphates / Q000737:chemistry / Q000378:metabolism; D000070539:Pleckstrin Homology Domains; D011485:Protein Binding; D021281:Quantitative Structure-Activity Relationship
chemical_list: D047309:Flavones; D005419:Flavonoids; D044948:Flavonols; D008081:Liposomes; D018129:Phosphatidylinositol Phosphates; C060974:phosphatidylinositol 3,4,5-triphosphate; D064413:3-Phosphoinositide-Dependent Protein Kinases; C017875:fisetin; C043562:flavone
keywords: Flavonoid; PDK1; Pleckstrin homology (PH) domain; PtdIns(3,4,5)P(3); QSAR