TPCK and quercetin act synergistically with vanadate to increase protein-tyrosine phosphorylation in avian cells
Van Wart-Hood, J.E.; Linder, M.E.; Burr, J.G.
Oncogene 4(10): 1267-1271
1989
ISSN/ISBN: 0950-9232 PMID: 2552375 Document Number: 339984
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.