Identification of a specific endogenous inhibitor of a casein kinase (G type) in bovine adrenal cortex as a glycosaminoglycan mixture

Abstract

Summary Bovine adrenal cortex contains an endogenous factor which selectively inhibits a particular class of cyclic nucleotide independent protein kinase activity (G type casein kinase). This previously purified inhibitor (D. JOB et al. , FEBS Lett., 98 , 303–308) was found to contain typical glycosaminoglycan components. Electrophoretic analysis and selective degradation procedures showed that the inhibitor preparation contained two major glycosaminoglycan moieties identified as heparin-like and chondroitin sulfate-like structures. The casein kinase G inhibitory properties appeared to require intact glycosaminoglycan chains. These findings may suggest a potential role of glycosaminoglycans in the modulation of intracellular protein phosphorylation processes by a particular type of messenger independent protein kinase.