Biomaterial Database

Bovine brain contains two types of phosphatidylinositol kinase. 1987

G Endemann, and S N Dunn, and L C Cantley

Department of Physiology, Tufts University, Boston, Massachusetts 02111.

Two phosphatidylinositol (PI) kinases from bovine brain were separated by rate zonal sucrose gradient centrifugation of detergent-solubilized membranes. Of the total PI kinase activity, 43% migrates on sucrose gradients with a size of approximately 55 kilodaltons (kDa); this kinase has properties similar to one of two PI kinase activities characterized in fibroblasts [Whitman, M., Kaplan, D. R., Roberts, T., & Cantley, L. (1987) Biochem. J. (in press)] and has been termed type 2. The remainder of the activity migrates in a second peak with a size of approximately 230 kDa. This enzyme possesses properties which are unlike both fibroblast PI kinase activities and has been termed type 3. The type 2 and type 3 enzymes have very different affinities for adenine nucleotides and are readily distinguishable by their sensitivities to inhibition by adenosine. The KMs of types 2 and 3 kinases for ATP are 54 and 742 microM, and the Kis for adenosine are 18 and 1520 microM, respectively. The two enzymes also differ in their affinities for PI, phosphatidylinositol 4-phosphate, and Mg2+ as well as in stimulation and inhibition by other phospholipids. When PI kinase from erythrocyte ghosts is fractionated by sucrose gradient centrifugation, only one peak of activity is observed which is indistinguishable from brain type 2 PI kinase.

UI	MeSH Term	Description	Entries
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D010770	Phosphotransferases	A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.	Kinases,Phosphotransferase,Phosphotransferases, ATP,Transphosphorylase,Transphosphorylases,Kinase,ATP Phosphotransferases
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D004910	Erythrocyte Membrane	The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.	Erythrocyte Ghost,Red Cell Cytoskeleton,Red Cell Ghost,Erythrocyte Cytoskeleton,Cytoskeleton, Erythrocyte,Cytoskeleton, Red Cell,Erythrocyte Cytoskeletons,Erythrocyte Ghosts,Erythrocyte Membranes,Ghost, Erythrocyte,Ghost, Red Cell,Membrane, Erythrocyte,Red Cell Cytoskeletons,Red Cell Ghosts
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man