The phosphatidylinositol kinase of rat brain

Abstract
The presence of a phosphatidylinositol kinase in homogenates of adult rat brain was shown by using labeled ATP [adenosine triphosphate] or labeled phosphatidylinositol. The kinase was activated by Mg2+ or Mn2+ and inhibited by Ca2+, Cu2+, K+, Na+ and F-. The detergents sodium deoxycholate, Cutscum and Triton X-100 markedly stimulated the reaction; sodium taurocholate, Tween-20 and cetyltrimethylammonium bromide were less effective. The activity of the enzyme was dependent on SH groups. The subcellular distribution of the kinase in brain resembled that of Na+-plus-K+-stimulated adenosine triphosphatase and 5[image] -nucleotidase.