Nambu Z, Terayama H
J Biochem. 1976 Oct;80(4):845-52. doi: 10.1093/oxfordjournals.jbchem.a131346.
Plasma membranes from rat liver were found to contain at least two types of specific binding sites for cyclic [3H] adenosine 3', 5'-monophosphate (c[3H]AMP) with apparent dissociation constants of 0.51 +/- 0.14 and 2.9 +/- 0.6 nM (O degrees), respectively. The levels of these binding sites in liver plasma membranes were about 0.60 +/- 0.20 and 1.3 +/- 0.5 pmole/mg protein. The highest affinity binders for c[3H]AMP were found to be reduced in amount in plasma membranes of ascites hepatomas to 1/3 to 1/4 as compared with liver membranes in the cases of AH-130 and AH-7974 and to an almost undetectable level in the case of AH-130F(N). No difference in the endogenous phosphorylation of plasma membranes by (gamma-32P])ATP was, however, detected among liver and hepatoma plasma membranes. Addition of cAMP or cGMP at various concentrations did not affect the endogenous phosphorylation of plasma membranes of these cells.
发现大鼠肝脏的质膜含有至少两种类型的特异性结合位点，用于结合环化[³H]腺苷3',5'-单磷酸（c[³H]AMP），其表观解离常数分别为0.51±0.14和2.9±0.6 nM（0℃）。这些结合位点在肝脏质膜中的水平约为0.60±0.20和1.3±0.5 pmol/mg蛋白质。与AH-130和AH-7974的肝脏膜相比，腹水肝癌细胞膜中c[³H]AMP的最高亲和力结合剂数量减少至1/3至1/4，而在AH-130F(N)的情况下几乎检测不到。然而，在肝脏和肝癌质膜之间未检测到（γ-³²P）ATP对质膜的内源性磷酸化有差异。添加不同浓度的cAMP或cGMP并不影响这些细胞的质膜内源性磷酸化。
