title: Tyrosine protein kinase activity in the DMBA-induced rat mammary tumor: inhibition by quercetin.
abstract: Tyrosine protein kinase activity was measured in membranes from DMBA-induced mammary tumors, with Angiotensin II as substrate. The apparent Km for the peptide was 3.3 mM. This enzymatic activity is inhibited by Ca+2; Mn+2 can replace Mg+2 with an increase in the Km for ATP from 47 /microM to 172 microM. The enzymatic activity was not affected by cyclic AMP but was inhibited in dose dependent manner by quercetin, a bioflavonoid which is known to inhibit proliferation of malignant cells in vitro.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000804:Angiotensin II; D000818:Animals; D002413:Cations, Divalent; D002462:Cell Membrane / Q000201:enzymology; D000242:Cyclic AMP / Q000494:pharmacology; D005260:Female; D005419:Flavonoids / Q000494:pharmacology*; D007700:Kinetics; D008325:Mammary Neoplasms, Experimental / Q000201:enzymology*; D010446:Peptide Fragments / Q000032:analysis; D010748:Phosphopeptides / Q000032:analysis; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D011505:Protein-Tyrosine Kinases; D011794:Quercetin / Q000494:pharmacology*; D051381:Rats
chemical_list: D002413:Cations, Divalent; D005419:Flavonoids; D010446:Peptide Fragments; D010748:Phosphopeptides; D047428:Protein Kinase Inhibitors; D000804:Angiotensin II; D015127:9,10-Dimethyl-1,2-benzanthracene; D011794:Quercetin; D000242:Cyclic AMP; D011505:Protein-Tyrosine Kinases