These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Purification and characterization of adrenocortical adenosine 3',5'-monoposphate-dependent protein kinases.
    Author: Ahrens H, Aiyar NV, Sharma RK.
    Journal: Endocrinology; 1986 Jun; 118(6):2168-79. PubMed ID: 3009153.
    Abstract:
    In this manuscript we describe in detail the purification and biochemical and immunological characterization of cAMP-dependent protein kinases in bovine adrenal cortex, rat adrenal gland, and isolated fasciculata cells of the rat. DEAE-cellulose chromatography of bovine adrenal cortex extract yielded two major (type I and type II) cAMP-dependent protein kinase peaks and one minor cAMP-binding peak. The minor peak (peak A) eluted at 30-80 mM NaCl and corresponded to the typical type I tetrameric structure of the holoenzyme. Peak B, eluting at 80-130 mM NaCl, comprised 10-15% of the total cAMP-binding activity and was identified as dimeric type I cAMP-binding regulatory subunit of the enzyme. Peak C (major peak) eluting at high salt (130-220 mM NaCl), was different from the typical type II holoenzyme; its mol wt was relatively low (123,000), and its cAMP-binding subunit was type I rather than type II. The native enzyme contained dimeric cAMP-binding regulatory subunit and suggested the presence of only a single catalytic subunit. Based on these results and on the reduced activation of its kinase activity by cAMP, we suggest a type I trimeric structure, R I2 C, of this enzyme. Most of the bovine adrenocortical extracts (62 of 68) did not contain type II cAMP-binding regulatory subunit of the enzyme. When present, its concentration (free or part of the holoenzyme) was less than 15% of the total cAMP-dependent protein kinases. These results were further supported by the studies with rat adrenal glands and isolated fasciculata cells derived from these glands, where only the type I cAMP receptor was found. We, therefore, conclude that in contrast to the current notion, adrenal cortex contains little, if any, enzyme containing type II cAMP-binding receptor. The predominant form of the holoenzyme contains a typical type I cAMP-binding receptor, but possesses an anomalous type II-like high salt elution pattern. We suggest that the trimeric structure of this enzyme contains a typical dimeric type I cAMP-binding subunit and a single catalytic subunit, R I2 C.
    [Abstract] [Full Text] [Related] [New Search]