title: A cyclic adenosine 3',5'-monophosphate-dependent histone kinase from pig brain. Purification and some properties of the enzyme.
abstract: A cyclic adenosine 3',5'-monophosphate-dependent histone kinase (ATP: protein phosphotransferase, EC 2.7.1.37) was isolated from pig brain. The enzyme has been purified 1140-fold; it is homogeneous on polyacrylamide gel electrophoresis and gel filtration. The estimated molecular weight of the enzyme is 120 000. Histone kinase dissociates into a catalytic subunit and a regulatory one (molecular weights 40 000 and 90 000, respectively). The catalytic subunit has been obtained in homogeneous state as evidenced by sodium dodecylsulphate-polyacrylamide gel electrophoresis. At all purification steps, enzymatic activity is stimulated 5-fold by cyclic AMP. An apparent Km value for cyclic AMP is about 3.3 - 10- minus 7 M. In the presence of cyclic AMP(5 - 10- minus 6 M), the Km value for ATP and F1 histone were 1.2 - 10- minus five and 3 - 10- minus 5 M, respectively. Optimum pH value for histone kinase is 6.5, its isoelectric point is situated at pH 4.6. The purified enzyme displays high specificity for the lysine-rich and moderately lysine-rich histones F1, F2a2 and F2b. Arginine-rich histones and other known protein substrates for cyclic AMP-dependent protein kinases (casein, Escherichia coli RNA polymerase, etc.) are extremely poor substrates for this enzyme.
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002845:Chromatography; D002850:Chromatography, Gel; D000242:Cyclic AMP / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D006656:Protamine Kinase / Q000302:isolation & purification* / Q000378:metabolism; D011485:Protein Binding; D011494:Protein Kinases / Q000302:isolation & purification*; D013329:Structure-Activity Relationship; D013552:Swine
chemical_list: D046911:Macromolecular Substances; D000242:Cyclic AMP; D011494:Protein Kinases; D006656:Protamine Kinase