Skene J H, Willard M
J Neurosci. 1981 Apr;1(4):419-26. doi: 10.1523/JNEUROSCI.01-04-00419.1981.
We report here certain properties of three polypeptides that are rapidly transported in greatly increased amounts during the regeneration of toad optic nerves. All three of these growth-associated polypeptides (GAPs) are associated with a membrane(s) with a buoyant density similar to the plasma membrane. Since none of these GAPs are solubilized substantially by washing the membranes in either low or high ionic strength media, they may be "integral membrane proteins. All three GAPs contain a significant number of polar amino acids (judging from their isoelectric points and their rapid electrophoretic migration under their native charge), suggesting that portions of each molecule must extent away from the membrane surfaces. One of these proteins (GAP-50) is a fucosylated glycoprotein. GAP-50 and GAP-43 appear to be transported preferentially to axon tips; GAP-24 may be distributed more uniformly along the axons. GAP-24 has an extremely short half-life (4 to 6 hr), while the maximum half-lives of GAP-43 (2 to 3 days) and GAP-50 (approximately 1 day) are longer. We discuss the relevance of these properties to possible roles for these polypeptides in the control of nerve regeneration.
我们在此报告三种多肽的某些特性，这些多肽在蟾蜍视神经再生过程中被大量快速转运。所有这三种生长相关多肽（GAPs）都与一种膜相关，其浮力密度与质膜相似。由于通过在低离子强度或高离子强度介质中洗涤膜，这些GAPs都不会被大量溶解，它们可能是“整合膜蛋白”。所有三种GAPs都含有大量极性氨基酸（从它们的等电点以及在天然电荷下的快速电泳迁移判断），这表明每个分子的部分必须延伸到膜表面之外。其中一种蛋白质（GAP - 50）是一种岩藻糖基化糖蛋白。GAP - 50和GAP - 43似乎优先被转运到轴突末端；GAP - 24可能更均匀地分布在轴突上。GAP - 24的半衰期极短（4至6小时），而GAP - 43（2至3天）和GAP - 50（约1天）的最大半衰期更长。我们讨论了这些特性与这些多肽在神经再生控制中可能发挥的作用的相关性。
