title: Natural biflavones as novel inhibitors of cathepsin B and K.
abstract: Cathepsin B and K, two important members in lysosomal proteases, involve in many serious human diseases, such as tumor and osteoporosis. In order to find their novel inhibitors, we performed the inhibition assays of cathepsin B and cathepsin K in vitro, randomly screened compounds from plants, and found six biflavones, named AMF1-5 and HIF, can potently inhibit cathepsin B and cathepsin K, especially AMF4 and HIF with IC(50) of 0.62 and 0.58 microM against cathepsin B. They are novel inhibitors for cathepsin B and K. Inhibition and flexible docking studies indicated that these biflavones are reversible inhibitors of cathepsin B, and their binding patterns and interaction modes with cathepsin B made them more specific to cathepsin B endopeptidase.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China.
authors.forename: G-Z
authors.initials: GZ
authors.lastname: Zeng
authors.forename: X-L
authors.initials: XL
authors.lastname: Pan
authors.forename: N-H
authors.initials: NH
authors.lastname: Tan
authors.forename: J
authors.initials: J
authors.lastname: Xiong
authors.forename: Y-M
authors.initials: YM
authors.lastname: Zhang
mesh_terms: D002401:Cathepsin B / Q000037:antagonists & inhibitors*; D056657:Cathepsin K; D002403:Cathepsins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008958:Models, Molecular; D008968:Molecular Conformation; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D011480:Protease Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D032489:Taxodium / Q000737:chemistry*
chemical_list: D047309:Flavones; D010936:Plant Extracts; D011480:Protease Inhibitors; D002403:Cathepsins; D002401:Cathepsin B; C534130:CTSK protein, human; D056657:Cathepsin K