White A M, Varney M A, Maeda N, Mikoshiba K, Watson S P
University Department of Pharmacology, Oxford, UK.
Biochim Biophys Acta. 1993 Feb 17;1175(3):307-11. doi: 10.1016/0167-4889(93)90222-b.
Ins(1,4,5)P3 receptors in adrenal cortical and cerebellar membranes can be distinguished by their affinities for Ins(1,4,5)P3 as well as the potencies with which heparin and Mg2+ inhibit binding. We have found that the differences in Ins(1,4,5)P3 affinity and heparin inhibition are maintained upon receptor solubilization and purification. In contrast to this, heparin-agarose affinity purification of solubilized cerebellar receptors reduces the potency of Mg2+ inhibition to that in adrenal cortex. These results suggest that Ins(1,4,5)P3 receptors in adrenal cortex are structurally distinct from those in cerebellum. Monoclonal antibodies raised against C- and N-terminal regions of mouse cerebellar Ins(1,4,5)P3 receptors recognize 250-300-kDa proteins in both rat cerebellum and bovine adrenal cortex.
肾上腺皮质和小脑膜中的肌醇-1,4,5-三磷酸（Ins(1,4,5)P3）受体可以通过它们对Ins(1,4,5)P3的亲和力以及肝素和镁离子抑制结合的效力来区分。我们发现，在受体溶解和纯化后，Ins(1,4,5)P3亲和力和肝素抑制的差异得以保留。与此相反，用肝素-琼脂糖亲和纯化溶解的小脑受体可将镁离子抑制的效力降低至肾上腺皮质中的水平。这些结果表明，肾上腺皮质中的Ins(1,4,5)P3受体在结构上与小脑中的不同。针对小鼠小脑Ins(1,4,5)P3受体的C端和N端区域产生的单克隆抗体可识别大鼠小脑和牛肾上腺皮质中的250-300 kDa蛋白质。
