title: Purification and characterization of bovine brain type I phosphatidylinositol kinase.
abstract: Investigation into the phosphatidylinositol kinase activities in bovine brain has revealed the presence of a type I PtdIns kinase activity. This classification is based upon potent inhibition by neutral detergent and the production of a phosphatidylinositol phosphate that can be distinguished from phosphatidyl-inositol-4-phosphate [PtdIns(4)P] by thin-layer chromatography. The enzyme has been substantially purified and the activity is associated with an 85-kDa polypeptide on SDS/polyacrylamide gel electrophoresis. Analysis of the product confirms the identification of the enzyme as a type I PtdIns kinase. The purified kinase has been characterized with respect to substrate dependence (Mg2+, ATP, PtdIns), substrate presentation (pure lipid versus mixed micelle) and specificity [PtdIns versus PtdIns(4)P and phosphatidylinositol 4,5-bisphosphate].
authors.affiliation: Department of Chemical Pathology, University College and Middlesex School of Medicine, London, England.
authors.forename: S J
authors.initials: SJ
authors.lastname: Morgan
authors.forename: A D
authors.initials: AD
authors.lastname: Smith
authors.forename: P J
authors.initials: PJ
authors.lastname: Parker
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D002845:Chromatography; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D008274:Magnesium / Q000494:pharmacology; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000378:metabolism; D010770:Phosphotransferases / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; C037178:phosphatidylinositol 4-phosphate; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; D019870:1-Phosphatidylinositol 4-Kinase; D008274:Magnesium