Panter S S, Butley M S, Malkinson A M
J Neurochem. 1981 Jun;36(6):2080-5. doi: 10.1111/j.1471-4159.1981.tb10837.x.
The cyclic AMP binding proteins present in mouse, rat, bovine, and sheep brains were compared. Extracts were isotopically labeled with 8-azido-cyclic [32P]AMP, a photoaffinity analog specific for cyclic AMP binding sites, and then subjected to two-dimensional gel electrophoresis. The resulting autoradiographic patterns were generally similar, but showed consistent species variations. Proteins identified by their size and phosphorylatability as regulatory subunits of Type II protein kinase isozymes were present in all species, but with slight variations in pI. A series of charge variants identified as regulatory subunits of Type I kinase isozymes on the basis of their size was also ubiquitously present, as were several smaller proteins postulated to be proteolytic fragments derived from the regulatory subunits. The major species difference was a series of labeled proteins found only in rodent brains and not in the brains of any ruminant, or in other rodent tissues. These proteins had a molecular weight of 54,000 and a pI range of 5.89--6.26, and could not be endogenously phosphorylated. The identities of these proteins and their relationship to the protein kinase regulatory subunits are unknown.
对存在于小鼠、大鼠、牛和羊大脑中的环磷酸腺苷（cAMP）结合蛋白进行了比较。提取物用8-叠氮基环[32P]AMP进行同位素标记，8-叠氮基环[32P]AMP是一种对cAMP结合位点具有特异性的光亲和类似物，然后进行二维凝胶电泳。所得放射自显影片模式总体相似，但显示出一致的物种差异。根据其大小和磷酸化能力鉴定为II型蛋白激酶同工酶调节亚基的蛋白质在所有物种中均存在，但pI略有差异。一系列根据其大小鉴定为I型激酶同工酶调节亚基的电荷变体也普遍存在，还有几种较小的蛋白质被推测为源自调节亚基的蛋白水解片段。主要的物种差异是一系列仅在啮齿动物大脑中发现的标记蛋白，而在任何反刍动物的大脑或其他啮齿动物组织中均未发现。这些蛋白质的分子量为54,000，pI范围为5.89 - 6.26，且不能被内源性磷酸化。这些蛋白质的身份及其与蛋白激酶调节亚基的关系尚不清楚。
