Isoenzyme patterns of protein kinase C and a phospholipid‐dependent but Ca²⁺‐inhibited enzyme fraction in the crude extracts of different tissues

Abstract

We compared the protein kinase C isoenzyme patterns of crude extracts of rabbit brain, cerebellum, spleen, thymus and human and pig granulocytes. The isoenzymes were fractionated by hydroxyapatite chromatography and the protein kinase C activity was determined with a synthetic oligopeptide substrate. In the extracts of several tissues we also observed an enzyme fraction which was activated by phosphatidylserine + diacylglycerol but inhibited by Ca z÷.Protein kinase C; Synthetic ofigopeptide substrate; Isoenzyme; Ca2+-inhibited enzyme fraction

Two components of type III protein kinase C with different substrate specificities and a phospholipid‐dependent but Ca2+‐inhibited protein kinase in rat brain

“…The crude cytosolic extract of rabbit brain showed a similar chromatographic pattern ( fig.l). Previously, we demonstrated a phospholipid-dependent but Ca2+-inhibited protein kinase fraction in extracts of rabbit brain, thymus and human and pig lymphocytes [22]. We attempted to demonstrate this enzyme in extracts of rat brain as well.…”

A protein kinase C‐related enzyme activity in Dictyostelium discoideum

“…Recently, also several PKC-related enzymes have been characterized [16][17][18][19][20][21]. Properties of these enzymes are similar, but not identical to those of the classical enzyme.…”

“…Furthermore, in the presence of PS plus DG, the activity of the D. discoideum enzyme is inhibited by Ca 2+, while the PS/DG stimulation of mammalian PKC is potentiated by Ca 2+. In this respect, the D. discoideum kinase more closely resembles a group of PKC-related enzymes that have been shown to be phospholipid-dependent, but Ca2÷-independent [17,18,20] or Ca2÷-inhibited [16,19].…”

Isoenzymes of protein kinase C in rat mammary tissue: changes in properties and relative amounts during pregnancy and lactation

“…Other antisera, peroxidase/anti-peroxidase (PAP) complexes and non-immune sera were from the Scottish Antibody Production Unit. The following synthetic peptides were prepared with an Applied Biosystems 43 lA solid-phase synthesizer: GS-peptide and PK-C pseudosubstrate inhibitor peptide ; Kemptide (Kemp et al, 1976); Walsh inhibitor peptide (Cheng et al, 1986); 'Farago' PK-C substrate peptide (Farago et al, 1989); SAMS peptide substrate for AMP-activated protein kinase (Davies et al, 1989). Lysine-rich histone (type Ills) was from Sigma.…”