Distribution and localization of adenosine 3':5'-monophosphate-dependent protein kinase in mammalian artery.
Among the three major vascular layers (the intima-inner, the media-middle smooth muscle, and the adventitia-outer connective tissue) over 90% of the total protein kinase activity was observed in the middle layer. Of various subcellular fractions of the vascular smooth muscle, the 105,000 g supernatant (cytosol fraction) showed the highest specific activity and represented more than two thirds of the total kinase present in this layer. DEAE-cellulose chromatography of the soluble enyzme revealed the existence of two major forms of cyclic AMP-dependent protein kinase, type I and type II, of which 60% of the total enzymatic activity was found in type II. A divalent cation was found to be essential for their phosphotransferase activity. Only Mg2+ and Co2+, but not Zn2+, Mn2+ or Ca2+ could satisfy the cation requirement. The phosphorylated substrate had the characteristics of a protein with a phosphoester bond.
D000818:Animals; D001158:Arteries / Q000201:enzymology*; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D000242:Cyclic AMP / Q000032:analysis / Q000502:physiology*; D008274:Magnesium / Q000494:pharmacology; D009119:Muscle Contraction; D009131:Muscle, Smooth, Vascular / Q000032:analysis; D010766:Phosphorylation; D011494:Protein Kinases / Q000032:analysis*
D000242:Cyclic AMP; D011494:Protein Kinases; D008274:Magnesium; D002118:Calcium