Shiu R P, Friesen H G
Biochem J. 1974 May;140(2):301-11. doi: 10.1042/bj1400301.
Receptors for human, simian, ovine, bovine and murine prolactin, human growth hormone and human placental lactogen have been identified in plasma-membrane-containing subcellular particles isolated from rabbit mammary glands. The association and dissociation of (125)I-labelled prolactin are time- and temperature-dependent processes, both being maximal at 37 degrees C. (125)I-labelled prolactin prepared by the enzymic iodination procedure with lactoperoxidase binds better to receptors than does the preparation obtained by using chloramine-t as the oxidizing agent. The binding of (125)I-labelled prolactin to receptors is strongly influenced by pH and ionic composition but not by many low-molecular-weight compounds tested, e.g. steroids, nucleotides and several drugs. Receptor activity is sensitive to trypsin and phospholipase C digestion, suggesting that protein and phospholipid moieties are essential for the binding of (125)I-labelled prolactin. The binding of (125)I-labelled prolactin to receptors is a saturable and reversible process. Scatchard and Lineweaver-Burk analyses suggest that (125)I-labelled prolactin has a high affinity for its receptor. Binding of (125)I-labelled prolactin to receptors does not result in the destruction of the hormone. Considerable prolactin-binding activity is also observed in subcellular fractions isolated from the adrenal gland, liver, ovary and kidney of the pregnant rabbit, a finding that is consistent with other reported actions of prolactin in these organs.
在从兔乳腺分离出的含质膜亚细胞颗粒中，已鉴定出人类、猴、绵羊、牛和鼠催乳素、人类生长激素及人类胎盘催乳素的受体。（125）I标记催乳素的结合和解离是时间和温度依赖性过程，二者在37℃时均达到最大值。用乳过氧化物酶通过酶促碘化法制备的（125）I标记催乳素比使用氯胺 - t作为氧化剂制备的制剂与受体的结合更好。（125）I标记催乳素与受体的结合受pH和离子组成的强烈影响，但不受许多测试的低分子量化合物（如类固醇、核苷酸和几种药物）的影响。受体活性对胰蛋白酶和磷脂酶C消化敏感，表明蛋白质和磷脂部分对于（125）I标记催乳素的结合至关重要。（125）I标记催乳素与受体的结合是一个可饱和且可逆的过程。Scatchard分析和Lineweaver - Burk分析表明，（125）I标记催乳素对其受体具有高亲和力。（125）I标记催乳素与受体的结合不会导致激素的破坏。在从怀孕兔的肾上腺、肝脏、卵巢和肾脏分离出的亚细胞组分中也观察到相当大的催乳素结合活性，这一发现与这些器官中催乳素的其他报道作用一致。
