title: Partial purification and characterization of protein tyrosine kinases from normal tissues.
abstract: Three membranous protein tyrosine kinases (PTKs) have been partially purified from human placenta and pig brain. The two placental enzymes (PTK-1 and -2) are distinct with respect to solubility in detergents, molecular weight, and enzymatic properties. The brain protein tyrosine kinase resembles placental PTK-1 with respect to molecular weight and some kinetic properties. However, stimulation of brain PTK is greater with Mn2+ than with Mg2+ whereas placental PTK-1 gives higher rates with Mg2+ than with Mn2+. All three enzymes are inhibited about 50% by 0.1 M NaCl. A monoclonal antibody raised in vitro against the brain enzyme inhibits brain PTK as well as placental PTK-2, but has no effect against PTK-1 or pp60src. It thus appears that these three enzymes are distinct entities that differ from each other both kinetically and immunologically. With synthetic tyrosine-glutamic acid polymers as a substrate, protein tyrosine kinase activity can be detected in crude extracts of membranes.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D001921:Brain / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007120:Immunochemistry; D036341:Intercellular Signaling Peptides and Proteins; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D010920:Placenta / Q000201:enzymology; D011247:Pregnancy; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D011685:Purine Nucleotides / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013552:Swine
chemical_list: D000911:Antibodies, Monoclonal; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D011685:Purine Nucleotides; C027606:L-glutamic acid-L-tyrosine copolymer; D008345:Manganese; D012965:Sodium Chloride; D011505:Protein-Tyrosine Kinases; D008274:Magnesium