McKerracher L, David S, Jackson D L, Kottis V, Dunn R J, Braun P E
Center for Research in Neuroscience, Montreal General Hospital Research Institute, Quebec, Canada.
Neuron. 1994 Oct;13(4):805-11. doi: 10.1016/0896-6273(94)90247-x.
Contact-dependent axon growth inhibitory activity is present in CNS myelin, but the inhibitory proteins have not been fully characterized. We report here that at least two peaks of inhibitory activity can be separated by fractionating solubilized CNS myelin proteins by DEAE chromatography. A major peak of inhibitory activity corresponded to the elution profile of myelin-associated glycoprotein (MAG). Immunodepletion of MAG from these inhibitory fractions removed neurite growth inhibition, whereas recombinant MAG (ectodomain) was a potent inhibitor of neurite outgrowth. Immunodepletion of MAG from total extracts of CNS myelin restored neurite growth up to 63% of control levels. These results establish that MAG is a significant, and possibly the major, inhibitor in CNS myelin; this has broad implications for axonal regeneration in the injured mammalian CNS.
接触依赖性轴突生长抑制活性存在于中枢神经系统髓磷脂中，但抑制蛋白尚未得到充分表征。我们在此报告，通过用DEAE色谱法对溶解的中枢神经系统髓磷脂蛋白进行分级分离，至少可以分离出两个抑制活性峰。一个主要的抑制活性峰与髓磷脂相关糖蛋白（MAG）的洗脱图谱相对应。从这些抑制级分中免疫去除MAG可消除神经突生长抑制，而重组MAG（胞外域）是神经突生长的有效抑制剂。从中枢神经系统髓磷脂总提取物中免疫去除MAG可使神经突生长恢复至对照水平的63%。这些结果表明，MAG是中枢神经系统髓磷脂中的一种重要且可能是主要的抑制剂；这对受伤的哺乳动物中枢神经系统中的轴突再生具有广泛的意义。
