title: In silico Screening of Chemical Libraries to Develop Inhibitors That Hamper the Interaction of PCSK9 with the LDL Receptor.
abstract: OBJECTIVE
  Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to the low density lipoprotein receptor (LDLR) and promotes degradation of the LDLR. Inhibition of PCSK9 either by reducing its expression or by blocking its activity results in the upregulation of the LDLR and subsequently lowers the plasma concentration of LDL-cholesterol. As a modality to inhibit PCSK9 action, we searched the chemical library for small molecules that block the binding of PCSK9 to the LDLR.
  
  
  METHODS
  We selected 100 chemicals that bind to PCSK9 where the EGF-AB fragment of the LDLR binds via in silico screening of the ChemBridge chemical library, using the computational GOLD algorithm analysis. Effects of chemicals were evaluated using the PCSK9-LDLR binding assay, immunoblot analysis, and the LDL-cholesterol uptake assay in vitro, as well as the fast performance liquid chromatography assay for plasma lipoproteins in vivo.
  
  
  RESULTS
  A set of chemicals were found that decreased the binding of PCSK9 to the EGF-AB fragment of the LDLR in a dose-dependent manner. They also increased the amount of the LDLR significantly and subsequently increased the uptake of fluorescence-labeled LDL in HepG2 cells. Additionally, one particular molecule lowered the plasma concentration of total cholesterol and LDL-cholesterol significantly in wild-type mice, while such an effect was not observed in Pcsk9 knockout mice.
  
  
  CONCLUSIONS
  Our findings strongly suggest that in silico screening of small molecules that inhibit the protein-protein interaction between PCSK9 and the LDLR is a potential modality for developing hypercholesterolemia therapeutics.
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul, Korea.|Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dong-Kook
authors.initials: DK
authors.lastname: Min
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyun-Sook
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul, Korea.|Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Narae
authors.initials: N
authors.lastname: Lee
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul, Korea.|Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chan Joo
authors.initials: CJ
authors.lastname: Lee
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Song
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ga Eul
authors.initials: GE
authors.lastname: Yang
authors.affiliation: Department of Biochemistry, Catholic Kwandong University College of Medicine, Gangneung, Korea.
authors.forename: Dojun
authors.initials: D
authors.lastname: Yoon
authors.affiliation: Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.|Department of Biochemistry and Molecular Biology, Institute of Genetic Science, Integrated Genomic Research Center for Metabolic Regulation, Yonsei University College of Medicine, Seoul, Korea. swpark64@yuhs.ac.
authors.forename: Sahng Wook
authors.initials: SW
authors.lastname: Park
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood; D056945:Hep G2 Cells; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases / Q000378:metabolism*; D011973:Receptors, LDL / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism*; D054852:Small Molecule Libraries
chemical_list: D008078:Cholesterol, LDL; D011973:Receptors, LDL; D054852:Small Molecule Libraries; D002784:Cholesterol; C472125:PCSK9 protein, human; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases; D012697:Serine Endopeptidases
keywords: LDL receptor; PCSK9; hypercholesterolemia; in silico; inhibitor; protein-protein interaction