Tyrosyl protein kinases in normal rat liver: identification and partial characterization.
Rat livers were fractionated and subcellular components were assayed for tyrosyl protein kinase activity. About 60% of the kinase activity in the cytoplasm sedimented with the microsomal fraction, whereas 40% remained in the supernatant. Purification of cytosolic and microsomal kinases by ion-exchange and gel filtration chromatography resolved a major species whose molecular mass was 75 kilodaltons (referred to as TPK 75) and a minor one whose molecular mass was greater than 160 kilodaltons. Partially purified TPK 75 phosphorylated a protein of the same molecular mass on tyrosine residues. The activity associated with TPK 75 was not stimulated by growth factors and was sensitive to thiol re-agents.
D000818:Animals; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D005260:Female; D008099:Liver / Q000201:enzymology*; D008970:Molecular Weight; D010750:Phosphoproteins / Q000032:analysis; D011494:Protein Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000201:enzymology
D010750:Phosphoproteins; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases