Szaro B G, Faulkner L A, Hunt R K, Loh Y P
Brain Res. 1984 Apr 16;297(2):337-55. doi: 10.1016/0006-8993(84)90575-4.
Axonal transport of proteins in the Xenopus optic nerve was examined by labeling proteins in the eye with [35S]methionine injected intraocularly and then analyzing the labeled proteins in the eye, nerve, and tectum on linear gradient SDS polyacrylamide gels at different times after the injection. Because the optic nerve in Xenopus is short, in order to distinguish transported proteins from locally synthesized proteins, the optic nerve on one side of the animal was crushed at the orbit (to stop axonal transport) 5-30 min prior to injection and the crushed and normal nerve segments were compared. Proteins in the intact nerve which were absent in the crushed nerve were identified as axonally transported proteins. By such criteria several waves corresponding to transported material moving at greater than or equal to 6 mm/day, 1.6-2.8 mm/day, and approximately 0.2 mm/day were detected in the nerve. The most rapid phases of transport could be further resolved in the optic tectum into 3 additional components at 60-96 mm/day, 30-48 mm/day, and 6-11 mm/day. Analysis of labeled proteins in the crushed nerves distal to the crush, near the injury site, revealed several locally synthesized proteins (mol. wt. 54,000, 48,000, 43,000 daltons) which were not present in normal, uninjured nerves. Such proteins are probably synthesized by glia in response to injury.
通过眼内注射[35S]甲硫氨酸标记眼中的蛋白质，然后在注射后不同时间，在SDS聚丙烯酰胺线性梯度凝胶上分析眼、神经和视顶盖中的标记蛋白质，研究了非洲爪蟾视神经中蛋白质的轴突运输。由于非洲爪蟾的视神经较短，为了区分运输的蛋白质和局部合成的蛋白质，在注射前5 - 30分钟在眼眶处挤压动物一侧的视神经（以阻断轴突运输），并比较挤压侧和正常侧的神经节段。挤压神经中不存在而完整神经中存在的蛋白质被鉴定为轴突运输蛋白。根据这些标准，在神经中检测到几波对应于运输物质移动速度大于或等于6毫米/天、1.6 - 2.8毫米/天和约0.2毫米/天的波。运输的最快阶段在视顶盖中可进一步解析为另外3个成分，移动速度分别为60 - 96毫米/天、30 - 48毫米/天和6 - 11毫米/天。对挤压处远端、靠近损伤部位的挤压神经中的标记蛋白质进行分析，发现了几种正常未损伤神经中不存在的局部合成蛋白质（分子量分别为54,000、48,000、43,000道尔顿）。这些蛋白质可能是神经胶质细胞响应损伤而合成的。
