Fryxell K J, Balzer D R, Brockes J P
J Neurochem. 1983 Feb;40(2):538-46. doi: 10.1111/j.1471-4159.1983.tb11316.x.
This is the first report of a quantitative radioimmunoassay for PO. The assay uses antigen-coated plastic microwells, with antibody binding detected by 125I-labeled protein A. Either peripheral myelin proteins or purified PO may be used as the antigen. Optimal extraction of tissue samples for PO immunoassay requires careful attention to the sodium dodecyl sulfate-to-protein ratio. Sodium dodecyl sulfate interference with antibody binding can be minimized by adding an excess of nonionic detergent and carrier protein to the incubation buffer. This method allows the detection of 0.8 ng of PO (20 ng/ml). Results from this assay showed little or no immunoreactivity in extracts of brain, centra myelin, liver, purified myelin basic proteins, cultured, purified secondary Schwann cells, or membrane preparations from these cells. PO was clearly detectable in Schwann cell cultures from 3- to 4-day-old rats at 12-18 h after dissociation (4% of the level in adult sciatic nerve) and in extracts of one-day-old rat sciatic nerve (2% of the level in adult nerve). Myelin basic protein radioimmunoassays showed that the ratio of PO to myelin basic protein is essentially constant in extracts of sciatic nerve from ne-day-old, four-day-old, and young adult rats. Another result was that PO levels are reduced in the trembler mouse sciatic nerve.
这是关于髓鞘蛋白零（PO）定量放射免疫测定的首篇报告。该测定采用包被抗原的塑料微孔板，通过¹²⁵I标记的蛋白A检测抗体结合情况。外周髓鞘蛋白或纯化的PO均可用作抗原。进行PO免疫测定时，组织样本的最佳提取需要仔细关注十二烷基硫酸钠与蛋白质的比例。通过向孵育缓冲液中加入过量的非离子去污剂和载体蛋白，可将十二烷基硫酸钠对抗体结合的干扰降至最低。此方法可检测到0.8纳克的PO（20纳克/毫升）。该测定结果显示，在脑、中枢髓鞘、肝脏、纯化的髓鞘碱性蛋白、培养的纯化二级雪旺细胞或这些细胞的膜制剂提取物中，几乎没有或没有免疫反应性。在解离后12 - 18小时的3至4日龄大鼠的雪旺细胞培养物中（为成年坐骨神经水平的4%）以及1日龄大鼠坐骨神经提取物中（为成年神经水平的2%），可清晰检测到PO。髓鞘碱性蛋白放射免疫测定表明，在新生、4日龄和年轻成年大鼠的坐骨神经提取物中，PO与髓鞘碱性蛋白的比例基本恒定。另一个结果是，震颤小鼠的坐骨神经中PO水平降低。
