Protein kinases derived from the conditioned media of human peripheral blood mononuclear cells

Two classes of cyclic nucleotide-independent protein kinase from the conditioned media of human peripheral blood mononuclear cells were detected. The first one was specific for histone, and was not retained by the remazol blue-agarose column. The second one was specific for casein and phosvitin, and was retained by the remazol blue-agarose column. Histone kinase activity was elevated in Con A-conditioned media. These peripheral blood mononuclear cells were subsequently fractionated into adherent and nonadherent cell populations. It was clear that histone kinase was secreted by adherent cells while casein and phosvitin kinases were secreted by nonadherent cells.