title: L655,240, acting as a competitive BACE1 inhibitor, efficiently decreases β-amyloid peptide production in HEK293-APPswe cells.
abstract: OBJECTIVE
  To identify a small molecule L655,240 as a novel β-secretase (BACE1) inhibitor and to investigate its effects on β-amyloid (Aβ) generation in vitro.
  
  
  METHODS
  Fluorescence resonance energy transfer (FRET) was used to characterize the inhibitory effect of L655,240 on BACE1. Surface plasmon resonance (SPR) technology-based assay was performed to study the binding affinity of L655,240 for BACE1. The selectivity of L655,240 toward BACE1 over other aspartic proteases was determined with enzymatic assay. The effects of L655,240 on Aβ40, Aβ42, and sAPPβ production were studied in HEK293 cells stably expressing APP695 Swedish mutant(K595N/M596L) (HEK293-APPswe cells). The activities of BACE1, γ-secretase and α-secretase were assayed, and both the mRNA and protein levels of APP and BACE1 were evaluated using real-time PCR (RT-PCR) and Western blot analysis.
  
  
  RESULTS
  L655,240 was determined to be a competitive, selective BACE1 inhibitor (IC(50)=4.47±1.37 μmol/L), which bound to BACE1 directly (K(D)=17.9±0.72 μmol/L). L655,240 effectively reduced Aβ40, Aβ42, and sAPPβ production by inhibiting BACE1 without affecting the activities of γ-secretase and α-secretase in HEK293-APPswe cells. L655,240 has no effect on APP and BACE1 mRNA or protein levels in HEK293-APPswe cells.
  
  
  CONCLUSIONS
  The small molecule L655,240 is a novel BACE1 inhibitor that can effectively decreases Aβ production in vitro, thereby highlighting its therapeutic potential for the treatment of Alzheimer's disease.
authors: School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China.
authors: Qin
authors: Q
authors: Lu
authors: Wu-Yan
authors: WY
authors: Chen
authors: Zhi-Yuan
authors: ZY
authors: Zhu
authors: Jing
authors: J
authors: Chen
authors: Ye-Chun
authors: YC
authors: Xu
authors: Morakot
authors: M
authors: Kaewpet
authors: Vatcharin
authors: V
authors: Rukachaisirikul
authors: Li-Li
authors: LL
authors: Chen
authors: Xu
authors: X
authors: Shen
mesh_terms: D053829:Amyloid Precursor Protein Secretases / Q000037:antagonists & inhibitors* / Q000235:genetics; D016229:Amyloid beta-Peptides / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors* / Q000235:genetics; D057055:Aspartic Acid Proteases / Q000037:antagonists & inhibitors; D001667:Binding, Competitive; D015153:Blotting, Western; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D031541:Fluorescence Resonance Energy Transfer; D057809:HEK293 Cells; D006801:Humans; D007211:Indoles / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology; D020349:Surface Plasmon Resonance; D014162:Transfection
chemical_list: D016229:Amyloid beta-Peptides; D007211:Indoles; D010446:Peptide Fragments; D054852:Small Molecule Libraries; C052517:L 655240; D053829:Amyloid Precursor Protein Secretases; D057055:Aspartic Acid Proteases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human