title: Rat brain and liver soluble phospholipase C: resolution of two forms with different requirements for calcium.
abstract: Two forms of phospholipase C, hydrolyzing specifically inositol phospholipids, are resoluted and partially purified from rat brain as well as liver cytosol by DEAE-cellulose followed by heparin-Sepharose, Sephacryl S-400, and aminohexyl-Sepharose column chromatographies. With phosphatidylinositol as substrate, at pH 7.4 one is most active at 10(-6) M Ca2+ (Type I) whereas the other requires 10(-3) M Ca2+ (Type II). At pH 5.5 both Type I and II are active at 10(-3) M Ca2+ but essentially inactive at lower concentrations of this divalent cation. Both Type I and II hydrolyze preferentially polyphosphoinositides particularly at lower concentrations of Ca2+.
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D002118:Calcium / Q000378:metabolism; D003600:Cytosol / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000302:isolation & purification* / Q000378:metabolism; D008099:Liver / Q000032:analysis*; D008970:Molecular Weight; D010716:Phosphatidylinositols / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity; D010738:Type C Phospholipases / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D010716:Phosphatidylinositols; D010738:Type C Phospholipases; D002118:Calcium