Characterization of a 34 kDa immunoreactive peptide with the anti protein kinase C antibody which can recognize part of the C4 region.

Among the immunoreactive peptides from hamster tissues with the antibody (Ab-1) which can recognize part of the C4 conserved region of protein kinase C (PKC), a peptide with 34 kDa (34 kDa species) is constitutively detected in the soluble and the nuclear but not in the particulate fractions. The partially purified 34 kDa species demonstrates no phospholipid-dependent or independent PKC activity and no phorbol 12,13 dibutyrate (PDBu) binding, and is not phosphorylated under the assay condition of PKC activity. The species inhibits the enzymic activity of the partially purified PKC from hamster brain in an uncompetitive manner with Ki of 200 +/- 23 nM.