title: A modified paper-binding procedure for the assay of nucleus-associated protein phosphokinases.
abstract: Previously existing paper-binding assay procedures gave results with large variations when employed for the measurement of nucleus-associated protein phosphokinase activities. However, a modified method, utilizing the binding of 32P-labeled phosphoprotein substrates to paper and employing washing procedures in 20% trichloroacetic acid at 60 degrees to 70 degrees C, gave highly reproducible results. This modified procedure was satisfactory with either chromatin or a nonhistone protein fraction derived therefrom as a source of enzyme, and dephosphophosvitin, lysine-rich histones, or casein as phosphoprotein substrates.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology*; D002843:Chromatin / Q000201:enzymology; D008722:Methods; D010209:Paper; D006656:Protamine Kinase / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D013997:Time Factors; D014238:Trichloroacetic Acid
chemical_list: D002843:Chromatin; D014238:Trichloroacetic Acid; D011494:Protein Kinases; D006656:Protamine Kinase