title: Conversion of protein kinase C from a Ca2+-dependent to an independent form of phorbol ester-binding protein by digestion with trypsin.
abstract: Tryptic fragments of protein kinase C containing the kinase (45 KDa) and phorbol ester-binding activity (38 KDa) were separated by Mono O column chromatography. The purified phorbol ester-binding fragment exhibits a higher affinity for phosphatidylserine than the native enzyme but comparable Kd for [3H]phorbol 12,13-dibutyrate as the native enzyme. This proteolytic fragment binds phorbol ester equally efficient either in the presence or absence of Ca2+ and the addition of the kinase fragment did not restore the Ca2+-requirement for the binding. These results indicate that protein kinase C is composed of two functionally distinct units which can be expressed independently after limited proteolysis with trypsin.
authors.forename: K P
authors.initials: KP
authors.lastname: Huang
authors.forename: F L
authors.initials: FL
authors.lastname: Huang
mesh_terms: D000818:Animals; D029742:Caenorhabditis elegans Proteins; D002118:Calcium / Q000494:pharmacology*; D002352:Carrier Proteins; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000378:metabolism; D010718:Phosphatidylserines / Q000494:pharmacology; D011493:Protein Kinase C / Q000032:analysis*; D011494:Protein Kinases / Q000032:analysis*; D051381:Rats; D011955:Receptors, Drug; D011971:Receptors, Immunologic / Q000032:analysis*; D014316:Tritium; D014357:Trypsin / Q000494:pharmacology*
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D010703:Phorbol Esters; D010718:Phosphatidylserines; D011955:Receptors, Drug; D011971:Receptors, Immunologic; C083141:phorbol ester binding protein; C027776:phorbol ester receptor; D014316:Tritium; D015240:Phorbol 12,13-Dibutyrate; D011494:Protein Kinases; D011493:Protein Kinase C; D014357:Trypsin; D002118:Calcium