A placental polypeptide activator of a membranous protein kinase and its relation to histone 1.
Crude transforming growth factor preparations of placenta contain a polypeptide that is required for the activity of a protein kinase that has been purified from plasma membrane preparations of Ehrlich ascites tumor cells. The kinase activator has been separated from transforming growth factor beta by reversed-phase HPLC and affinity chromatography. Like the transforming growth factor, it is heat stable and trypsin labile, but it is not inactivated by dithiothreitol. In sodium dodecyl sulfate/polyacrylamide gel electrophoresis the purified preparation shows a major double band at about 31,000 daltons. Comparisons of electrophoretic mobility, protein kinase stimulatory activity, and cross-reactivity with an antibody against histone 1 suggest that the placental activator is identical with histone 1.
D002462:Cell Membrane / Q000201:enzymology; D002851:Chromatography, High Pressure Liquid; D004789:Enzyme Activation; D005260:Female; D006657:Histones / Q000502:physiology; D006801:Humans; D007700:Kinetics; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000302:isolation & purification / Q000502:physiology*; D011494:Protein Kinases / Q000378:metabolism*
D006657:Histones; D011257:Pregnancy Proteins; D011494:Protein Kinases