Chou K H, Nolan C E, Jungalwala F B
J Neurochem. 1985 Jun;44(6):1898-912. doi: 10.1111/j.1471-4159.1985.tb07186.x.
Subcellular fractionation of rat sciatic nerve was developed to determine the specific localization of gangliosides in the nerve membrane fractions. Myelin, microsomal, and a plasma membrane-like fraction were isolated and purified by sucrose density gradient centrifugation. These subfractions were characterized by electron microscopy, marker enzyme assays, and their protein and lipid profile. In rat sciatic nerve myelin, 90 mol% of the total gangliosides were monosialogangliosides. LM1 (sialosyl-lactoneotetraosylceramide) (61 mol%) and GM3 (21%) were the major gangliosides of the rat nerve myelin. Two other neolacto series of gangliosides, viz., sialosyl-lactoneonorhexaosylceramide and sialosyl-lactoneooctaosylceramide, were also localized mostly in the myelin fraction. GM1 was only a minor (less than 2%) ganglioside in myelin. The ganglioside patterns of the microsomal and plasma membrane-like fractions were similar with minor quantitative differences and were entirely different from that of myelin. Monosialogangliosides were approximately 70-75 mol% of the total in these fractions. The major gangliosides of the microsomal and plasma membrane-like fractions were GM3 (approximately 40%) and GM1 (approximately 20%). LM1 in these fractions was minimal (less than approximately 5%). Significant amounts of GM3 with N-glycolylneuraminic acid (approximately 10%) and GM1b (4-14%) were also identified in the microsomal and plasma membrane-like fractions but not in myelin. These and the higher lactoneo series of gangliosides have not been previously reported to be present in the rat nervous system. Almost exclusive localization of LM1 in myelin in rat peripheral nervous system is consistent with our previous observation that deposition of LM1 in the nerve with age was very similar to that of myelin marker lipids cerebrosides and sulfatides.
开发大鼠坐骨神经亚细胞分级分离法以确定神经节苷脂在神经膜组分中的特定定位。通过蔗糖密度梯度离心分离并纯化髓磷脂、微粒体和类质膜组分。这些亚组分通过电子显微镜、标记酶分析及其蛋白质和脂质谱进行表征。在大鼠坐骨神经髓磷脂中，总神经节苷脂的90摩尔%是单唾液酸神经节苷脂。LM1（唾液酸 - 乳糖新四糖神经酰胺）（61摩尔%）和GM3（21%）是大鼠神经髓磷脂的主要神经节苷脂。另外两种新乳糖系列神经节苷脂，即唾液酸 - 乳糖新六糖神经酰胺和唾液酸 - 乳糖新八糖神经酰胺，也主要定位于髓磷脂组分中。GM1在髓磷脂中只是次要的（不到2%）神经节苷脂。微粒体和类质膜组分的神经节苷脂模式相似，只是在数量上有微小差异，且与髓磷脂的模式完全不同。单唾液酸神经节苷脂约占这些组分总量的70 - 75摩尔%。微粒体和类质膜组分的主要神经节苷脂是GM3（约40%）和GM1（约20%）。这些组分中的LM1极少（不到约5%）。在微粒体和类质膜组分中还鉴定出大量含N - 羟乙酰神经氨酸的GM3（约10%）和GM1b（4 - 14%），但在髓磷脂中未发现。这些以及更高的乳糖新系列神经节苷脂此前尚未报道存在于大鼠神经系统中。LM1在大鼠外周神经系统的髓磷脂中几乎完全定位，这与我们之前的观察结果一致，即随着年龄增长，LM1在神经中的沉积与髓磷脂标记脂质脑苷脂和硫脂的沉积非常相似。
