Sharma S K, Bradford S, Babitch J A, Couch E F
Eur J Cell Biol. 1986 Mar;40(1):44-52.
Chick brain synaptosomes were fractionated by affinity chromatography on concanavalin A-Sepharose. Three subfractions were obtained. One, designated UBF, was not bound to the affinity adsorbent and represented 36% of the total synaptosomal protein treated with the beads. A second fraction, designated BF1, adhered to concanavalin A-Sepharose exclusively through its carbohydrate recognition site. The third fraction, called BF2, bound to the beads through hydrophobic interactions and represented about 20% of the total synaptosomal protein. About 20% of the total synaptosomal protein was found to be retarded on three ligand-less gels, with potential for only hydrophobic interactions. This binding can be reversed, however, by ethylene glycol, a result indicating hydrophobic binding sites on the synaptosomes. Enzyme marker studies and electron microscopy showed differences between UBF, BF1, and BF2, mainly with respect to mitochondrial contamination. Binding studies with [3H]-Con A show the absence of Con A-specific carbohydrates from the surface of UBF or BF2. As expected strong and specific binding between [3H]-Con A and [3H] BF1 was observed. These findings are discussed in relation to a model for the interior working of the synaptosomes.
鸡脑突触体通过伴刀豆球蛋白A - 琼脂糖亲和层析进行分离。得到了三个亚组分。一个命名为UBF，未与亲和吸附剂结合，占经珠子处理的突触体总蛋白的36%。第二个组分命名为BF1，仅通过其碳水化合物识别位点附着在伴刀豆球蛋白A - 琼脂糖上。第三个组分称为BF2，通过疏水相互作用与珠子结合，占突触体总蛋白的约20%。发现约20%的突触体总蛋白在三种无配体凝胶上迁移受阻，仅具有疏水相互作用的可能性。然而，这种结合可以被乙二醇逆转，这一结果表明突触体上存在疏水结合位点。酶标记研究和电子显微镜显示UBF、BF1和BF2之间存在差异，主要体现在线粒体污染方面。用[³H] - 伴刀豆球蛋白A进行的结合研究表明，UBF或BF2表面不存在伴刀豆球蛋白A特异性碳水化合物。正如预期的那样，观察到[³H] - 伴刀豆球蛋白A与[³H] BF1之间有强烈且特异性的结合。结合突触体内部工作模型对这些发现进行了讨论。
