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α7-烟碱型乙酰胆碱受体 (α7受体 )广泛分布于中枢及外周神经系统 ,参与多种生理功能的调节并与老年性痴呆等疾病有重要联系。在培养的鸡胚睫状神经节及大鼠海马神经元上 ,我们发现牛血清白蛋白能大幅度 (达～ 10倍 )增强α7受体电流 ,这一作用不依赖膜电位 ,受体与激动剂亲合力增加也不是直接原因。再纯化实验及蛋白酶消化实验证明牛血清白蛋白的作用不大可能是由于与其结合的其他污染分子造成 ,而更可能是由于其本身的作用。牛、马、羊、狗、猪等动物的血清白蛋白有类似的增强作用 ,而鸡、大鼠、小鼠、人的血清白蛋白则无增强作用 ,表明白蛋白的作用有特异性。不同种动物血清白蛋白氨基酸顺序的差异提示我们可能能够用合成的小分子多肽来模拟血清白蛋白对α7受体的增强作用 ,并以此为线索来发现体内存在的内源性类似物。
The α7-nicotinic acetylcholine receptor (α7 receptor) is widely distributed in the central and peripheral nervous system, is involved in the regulation of various physiological functions and has an important connection with diseases such as senile dementia. In cultured chicken embryonic ciliary ganglion neurons and rat hippocampal neurons, we found that bovine serum albumin significantly (up to 10-fold) potentiates [alpha] 7 receptor currents, independent of membrane potential, receptor and agonist Agent affinity is not the direct cause of increase. Purification experiments and protease digestion experiments show that bovine serum albumin is less likely to be caused by other contaminating molecules associated with it and more likely by its own role. Serum albumin of cattle, horses, sheep, dogs, pigs and other animals had a similar enhancement effect, while serum albumin of chicken, rat, mouse and human had no enhancement effect, indicating the specificity of albumin. The differences in amino acid sequence of serum albumin from different species of animals suggest that we may be able to model the potentiation of α7 receptors by serum albumin using small molecule peptides synthesized, and use this as a clue to find endogenous analogues present in vivo.