Abstract
Butein, a plant polyphenol, was shown to be a specific protein tyrosine kinase inhibitor. This compound inhibited not only the epidermal growth factor (EGF)-stimulated auto-phosphotyrosine level of EGF receptor in HepG2 cells but also tyrosine-specific protein kinase activities of EGF receptor (IC50 = 65 microM) and p60c-src (IC50 = 65 microM) in vitro. The inhibition was competitive to ATP and non-competitive to the phosphate acceptor, poly (Glu, Ala, Tyr) 6:3:1 for EGF receptor tyrosine kinase. In contrast, butein non-significantly inhibited the activities of serine- and threonine-specific protein kinases, such as protein kinase C (PKC) and cAMP-dependent protein kinase (PKA).
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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CSK Tyrosine-Protein Kinase
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Carcinoma, Hepatocellular / enzymology
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Chalcone / analogs & derivatives*
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Chalcone / pharmacology
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Chalcones
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Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
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Enzyme Inhibitors / pharmacology*
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Epidermal Growth Factor / pharmacology
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ErbB Receptors / metabolism
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Flavonoids*
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Humans
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Kinetics
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Molecular Structure
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Phenols / pharmacology
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Phosphorylation
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Polymers / pharmacology
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Polyphenols
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Protein Kinase C / antagonists & inhibitors
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Protein-Tyrosine Kinases / antagonists & inhibitors
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Receptor Protein-Tyrosine Kinases / antagonists & inhibitors*
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Tumor Cells, Cultured
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src-Family Kinases
Substances
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Chalcones
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Enzyme Inhibitors
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Flavonoids
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Phenols
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Polymers
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Polyphenols
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butein
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Chalcone
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Epidermal Growth Factor
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ErbB Receptors
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Protein-Tyrosine Kinases
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Receptor Protein-Tyrosine Kinases
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CSK Tyrosine-Protein Kinase
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src-Family Kinases
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CSK protein, human
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Cyclic AMP-Dependent Protein Kinases
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Protein Kinase C