STORAGE OF SEROTONIN AND SEROTONIN BINDING PROTEIN IN SYNAPTIC VESICLES
STORAGE OF SEROTONIN AND SEROTONIN BINDING PROTEIN IN SYNAPTIC VESICLES
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突触小泡中血清素和血清素结合蛋白的储存
DOI：
10.1111/j.1471-4159.1979.tb11703.x
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发表时间：
1979
影响因子：
4.7
通讯作者：
M. Gershon
中科院分区：
文献类型：
--
作者：
H. Tamir;M. Gershon
我们使用DeLorenzo & Freedman（1978）新引入的分离突触囊泡的方法来确定这些囊泡是否同时含有5-羟色胺（5-HT）和5-羟色胺结合蛋白（SBP）。得到两个级分。55，000 g级分形态不均匀，含有包被的囊泡。一个135，0000个囊泡（直径）。51.3 nm）级分在超微结构中是均匀的，并且不含包被的囊泡。该组分中SBP的比活性远高于上清液中的SBP比活性。与SBP不同，在135，000 g级分中出现非常少的乳酸脱氢酶活性。从囊泡中提取的可溶性蛋白质和SDS凝胶上的上清液蛋白质的多肽谱之间观察到定性和定量的差异。因此，在135，000 g级分的囊泡中胞质溶胶的截留是最小的。135，000 g囊泡的5-HT浓度为5.5 ng/mg蛋白，上清液中为11.3 ng/mg蛋白。135，000 g囊泡部分中的ATP浓度仅为0.8 ng/mg Pr。横切兔脊髓，以确定SBP是否通过快速轴突运输在轴突中向近端-远端移动，如预测的突触囊泡成分。SBP以与快速转运（78 mm/天）一致的速率在切割线以上累积。SBP活性下降到横断点的尾部，没有证据表明SBP可能逆行转运，例如病变下方的蓄积。这些实验表明，SBP可能是合成在多巴胺能神经元的细胞体和一些被迅速运输下来的轴突储存在终端的囊泡。
We have used the newly introduced method of DeLorenzo & Freedman (1978) for isolating synaptic vesicles to determine if such vesicles contain both serotonin (5‐HT) and serotonin binding protein (SBP). Two fractions were obtained. A 55, 000 g fraction was morphologically heterogeneous and contained coated vesicles. A 135, 0000 vesicle (dia. 51.3 nm) fraction was homogeneous in ultra‐structure and contained no coated vesicles. The specific activity of SBP in this fraction was much higher than that in the supernatant. Unlike SBP, very little lactic dehydrogenase activity appeared in the 135, 000 g fraction. Qualitative and quantitative differences were observed between the polypeptide profiles of soluble proteins extracted from the vesicles and supernatant proteins on SDS gels. Therefore, entrapment of cytosol in the vesicles of the 135, 000 g fraction was minimal. The 5‐HT concentration of the 135, 000 g vesicles was 5.5 ng/mg protein and in the supernatant, 11.3 ng/mg protein. The ATP concentration in the 135, 000 g vesicle fraction was only 0.8 ng/mg Pr. Rabbit spinal cords were transected in order to determine if SBP is moved proximo‐distally in axons by rapid axonal transport as would be predicted for a constituent of synaptic vesicles. SBP accumulated above the cut at a rate consistent with fast transport (78 mm/day). SBP activity fell caudal to the point of transection and there was no evidence, such as an accumulation below the lesion, that might indicate retrograde transport of SBP. These experiments indicate that SBP is probably synthesized in the cell bodies of serotonergic neurons and some is rapidly transported down axons to be stored in terminals in vesicles.