title: TPCK and quercetin act synergistically with vanadate to increase protein-tyrosine phosphorylation in avian cells.
abstract: We have found four compounds that act synergistically with the phosphotyrosine phosphatase inhibitor sodium orthovanadate (Na3VO4) to greatly increase the extent of protein-tyrosine phosphorylation in both uninfected chick embryo fibroblasts (CEF) and their Rous sarcoma virus-transformed counterparts (RSV-CEF). These four inhibitors fall into two categories: the chymotrypsin-specific protease inhibitors, tosyl-phenylalanine-chloromethyl ketone (TPCK) and N-carbobenzoxy-1-phenylalanine-chloromethyl ketone (ZPCK); and certain bioflavonoids which can competitively inhibit ATP-binding, quercetin and phloretin.
authors.affiliation: Program in Molecular Biology, University of Texas, Dallas, Richardson 75080.
authors.forename: J E
authors.initials: JE
authors.lastname: Van Wart-Hood
authors.forename: M E
authors.initials: ME
authors.lastname: Linder
authors.forename: J G
authors.initials: JG
authors.lastname: Burr
mesh_terms: D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology*; D000818:Animals; D001358:Avian Sarcoma Viruses; D002642:Chick Embryo; D004357:Drug Synergism; D005419:Flavonoids / Q000494:pharmacology*; D015688:Oncogene Protein pp60(v-src) / Q000037:antagonists & inhibitors; D010693:Phloretin / Q000494:pharmacology; D010766:Phosphorylation; D011506:Proteins / Q000378:metabolism*; D011794:Quercetin / Q000494:pharmacology*; D015842:Serine Proteinase Inhibitors; D014108:Tosylphenylalanyl Chloromethyl Ketone / Q000494:pharmacology*; D014268:Trifluoperazine / Q000494:pharmacology; D014443:Tyrosine / Q000378:metabolism*; D014638:Vanadates / Q000494:pharmacology*
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D005419:Flavonoids; D011506:Proteins; D015842:Serine Proteinase Inhibitors; D014268:Trifluoperazine; D014638:Vanadates; D014108:Tosylphenylalanyl Chloromethyl Ketone; D014443:Tyrosine; D011794:Quercetin; D015688:Oncogene Protein pp60(v-src); D010693:Phloretin