1973 Volume 23 Issue 4 Pages 515-522
Studies on the zonal function of CAMP-binding protein (regulatory protein) and CAMP-dependent protein kinases in bovine adrenal glands have been made. Partially purified CAMP-binding protein from bovine adrenal gland divided into three zones, the capsular (zona glomerulosa), the decapsulated (zona fasciculata and reticularis) and the medulla gland was found in microsomal and cytosol fractions. The affinity and activity of the protein binding to CAMP from the cortex (the capsular, Ka, 4.7×10-9 M ; activity, 4.6 p mole/mg protein, and the decapsulated, Ka, 4.2×10-9 M; activity, 4.7 p mole/mg protein) was higher than from the medulla (Ka, 17×10-9 M; activity, 2.2 p mole/mg protein). Two CAMP-dependent protein kinases, partly associated with CAMP-binding regulatory protein were partially purified from the cortex (the capsular and the decapsulated gland) and the medulla gland. The Km (8.6×10-8 M) for CAMP of protein kinases from the cortex (the decapsulated gland) was lower than the Km (1.7×10-7) from the medulla gland. Higher activity of CAMP-dependent protein kinases from the cortex than the medulla was discussed on the basis of differences in their regulatory proteins to which CAMP binds in an allosteric manner.
